Wireless tag testing

Abstract

A method of testing a wireless tag by a test unit includes: transmitting a signal that substantially simultaneously encourages a plurality of wireless tags within a test area of the test unit; waiting for a prescribed amount of time sufficient to allow all the wireless tags in the test area to have opportunity to respond with the transmitted messages, each transmitted message including a unique identifier of the wireless tag; which of the plurality of wireless tags are good and which of the plurality of wireless tags are bad are determined based on information about the identities of those wireless tags in the test area and sent messages (if any) received by the tester from the wireless tags in the test area containing respective unique identifiers.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. non-provisional patent application No. 17 / 804,734, filed on May 31, 2022, the contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to testing of wireless tags, such as Bluetooth wireless tags, to ensure that they are free of defects and therefore suitable for deployment. Background Art

[0004] Testing wireless tags one at a time is very time consuming. Usually, all functions of the wireless tags are tested, that is, all system paths of the wireless tags. Some wireless tags can be designed to collect electromagnetic energy of one or more frequencies to provide power for their operation. Each such collecting wireless tag is charged when it arrives at the test area, and then each wireless tag is fully tested. This test requires the start and stop process of transmitting wireless tags so that they stay in the test area long enough to be tested.

[0005] In various prior art test arrangements, the test area can (but not necessarily) be located in a chamber that is at least partially isolated from other radio waves. Regardless of whether the test area is a chamber, the wireless tag must remain in the test area of ​​the test arrangement for a long enough time to charge and fully test the wireless tag.

[0006] Another similar test mechanism uses a far-field antenna to charge each wireless tag, and then uses a near-field antenna to fully test each wireless tag. In addition, this test requires a start and stop process for the wireless tag transmission so that each wireless tag stops in the test area of ​​the test arrangement, specifically within the range of the near-field antenna, for a sufficient time to perform the test.

[0007] Another issue with testing is that some types of wireless tags may be expected to be able to communicate on multiple frequencies. However, before the wireless tag is "converted," it may only be able to communicate on a limited set of frequencies on which it is expected to eventually be able to communicate. Conversion is the process of adding additional layers to the wireless tag, which can change the characteristics of the wireless tag's antenna. Given the above, testing is usually performed after conversion and on multiple expected communication frequencies of the wireless tag.

[0008] Prior art wireless tag testing requires hundreds of milliseconds to several seconds per wireless tag. It would be advantageous to provide a solution that accelerates wireless tag testing properties. Summary of the invention

[0009] The embodiments disclosed herein are merely examples of many possible advantageous uses and implementations of the innovative teachings presented herein. In general, statements made in the specification of the present application do not necessarily limit any of the various claimed embodiments. In addition, some statements may apply to some inventive features but not to other features. In general, unless otherwise stated, singular elements may be plural and vice versa without loss of generality. In the accompanying drawings, the same numerals refer to the same parts in several views.

[0010] Certain embodiments disclosed herein include a method for testing wireless tags by a test unit. The method includes: sending a signal that substantially simultaneously excites a plurality of wireless tags within a test area of ​​the test unit; waiting a specified amount of time sufficient to allow all wireless tags in the test area to have an opportunity to respond with a sent message, each sent message including a unique identifier of the wireless tag; determining which of the plurality of wireless tags are good and which of the plurality of wireless tags are bad based on information about the identities of those wireless tags in the test area and the sent messages (if any) received by the tester from the wireless tags in the test area that include the respective unique identifiers.

[0011] Certain embodiments disclosed herein include a method of testing wireless tags by a test unit, comprising: determining which, if any, of the plurality of wireless tags in a test area are good based on responses received from one or more of the plurality of wireless tags in response to an excitation signal sent in the test area and information about which wireless tags constitute the plurality of wireless tags in the test area.

[0012] BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In the attached picture:

[0014] Figure 1 A schematic diagram of an illustrative wireless tag, such as an Internet of Things (IoT) wireless tag, is shown, which can be used to test various embodiments of the wireless tag;

[0015] Figure 2 According to an embodiment, a method for testing a wireless tag (e.g., Figure 1 A schematic diagram of a tester for the function of a wireless tag;

[0016] Figure 3 A wafer including a plurality of integrated circuits (ICs) or dies arranged in a matrix is ​​shown, and the dies are placed on a wireless tag substrate;

[0017] Figure 4 It shows that Figure 3 An array of wireless tags arranged in a matrix form is also shown, and a unique identifier of each wireless tag is also shown;

[0018] Figure 5 It shows that according to the embodiment Figure 2 Another view of an illustrative embodiment of a tester;

[0019] Figure 6 An illustrative process for a tester to test a group of wireless tags is shown in flowchart form;

[0020] Figure 7 An illustrative process for establishing a relationship between a die's position in a matrix and its unique ID is shown in flowchart form; and

[0021] Figure 8 is a more detailed diagram of an illustrative arrangement of a controller that may be used to implement a tester or wireless tag. DETAILED DESCRIPTION

[0022] It is worth noting that the embodiments disclosed herein are merely examples of many advantageous uses of the innovative teachings herein. In general, statements made in the specification of the present application do not necessarily limit any of the various claimed embodiments. In addition, some statements may apply to some inventive features but not to other features. In general, unless otherwise stated, singular elements may be plural and vice versa without loss of generality.

[0023] Unless otherwise expressly specified herein, the accompanying drawings are not drawn to scale.

[0024] In the description, components with the same number in different drawings refer to substantially the same components.

[0025] A method and system for rapidly testing multiple wireless tags in a matrix in a short period of time is disclosed. The method actually includes two stages. In the first stage, it is determined which wireless tags are under test. In the second stage, the wireless tags are stimulated and wireless tags that are known to be tested but not responding are declared bad, while all remaining tested wireless tags are declared good.

[0026] More specifically, the wireless tags can be arranged in a one-dimensional or two-dimensional matrix and located in the test area at the same time. Because the position of each wireless tag in the matrix is ​​known, it is known which wireless tags are in the test area. The wireless tags in the test area are charged and their respective calibrations are performed simultaneously. Due to the nature of wireless protocols, such as clear send or send and test protocols, such as ALOHA-type protocols, eventually all operable wireless tags will send a signal including a unique identifier (identifier, ID) of the wireless tag. The tester receives this transmitted signal. Because the tester knows which wireless tags are in the test area and what their respective IDs are, any wireless tag from which the tester does not receive a signal (including its ID) will be determined to be bad. The remaining wireless tags that receive the signal will be determined to be in good condition and have passed the test.

[0027] Figure 1 1 is a schematic diagram of an illustrative wireless tag 100 (e.g., an Internet of Things (IoT) wireless tag) that can be used to test various embodiments of the wireless tag. The wireless tag 100 includes an integrated circuit (IC or chip) 120 and at least one antenna (e.g., antennas 110-2, 110-1) placed on an inlay 105. In an embodiment, the inlay 105 is a single-layer inlay that includes the integrated circuit 120 connected to at least one antenna 110-1, 110-2 and can be mounted on a substrate (not shown). The substrate is a single-layer material that can be a single metal layer or any suitable integrated circuit mounting material, such as a printed circuit board (PCB), silicon, flexible printed circuits (FPC), low temperature co-fired ceramic (LTCC), polyethylene terephthalate (PET), polyimide (PI), and paper.

[0028] In the illustrative embodiment, the wireless tag 100 includes a pair of antennas 110-1 and 110-2, which are etched into the inlay 105. The first antenna 110-1 is used to harvest energy from the surrounding radio frequency (RF) signals, and the second antenna 110-2 is used for communication, such as sending and receiving signals (such as Bluetooth Low Energy (BLE) signals). Each of the antennas 110-1 and 110-2 can be a type including a loop antenna, a large loop with two feeds, a dipole antenna with two transformer feeds, and similar configurations. It should be noted that the transmitting second antenna 110-2 can also be used to harvest energy. In addition, in some configurations, multiple antennas can be used to harvest energy, each antenna being designed to receive signals of different frequencies.

[0029] In an embodiment, the wireless tag 100 further includes a capacitor 130, which may be implemented as an on-die capacitor, an external passive capacitor, etc. The energy harvesting function and energy usage are under the direction of the integrated circuit 120. In another embodiment, the wireless tag 100 may include a printed battery.

[0030] In order to ensure that the wireless tag 100 can operate correctly, it needs to be tested to ensure that it can receive signals, harvest energy, charge the capacitor, and send signals.

[0031] The first antenna 110-1 of the acquisition wireless tag 100 receives energy on the RF signal of one or more frequency bands. These frequency bands are specific to the parameters of the wireless tag, which include but are not limited to physical parameters such as antenna length, thickness, conductivity, resistivity, and antenna properties such as gain, radiation pattern, beam width, polarization, and impedance. It should be noted that even a slight difference or offset between the parameters of the two antennas may result in different acquisition frequencies.

[0032] According to the acquisition frequency, the acquisition first antenna 110-1 of the wireless tag 100 is tuned to a frequency band within which the wireless tag can most effectively receive the RF signal received through the frequency band and convert the signal into a direct current (DC) voltage. In an embodiment, the DC voltage is stored on a capacitor 130 or a similar power storage device.

[0033] The energy E on capacitor 130 is related to the DC voltage V by the following equation: Where C is the capacitance of the capacitor. As described above, the inlay 105 of the wireless tag 100 may include multiple antennas, more than one of which may be configured as a separate collector. In an embodiment, each collector is connected to a separate storage capacitor, while in another embodiment, a single storage capacitor is shared by multiple collectors, allowing the shared storage capacity of the wireless tag 100 to be increased.

[0034] Bluetooth Low Energy (BLE) is a personal area network protocol that supports wireless connections on the 2.4 GHz industrial, scientific and medical (ISM) band, with a range of even more than 250 meters. BLE signals are used for low-power devices, such as battery-fewer wireless tags, such as wireless tag 100. Bluetooth and Bluetooth Low Energy communications operate in the far field, and their protocols can support multiple connections and multiple device connections at the same time. Other low-energy communication protocols include LoRa, nRF, Ultra low energy ( Ultra LowEnergy, DECT ULE), Etc., can be used for wireless tags in a manner similar to Bluetooth and BLE. For simplicity and teaching purposes, the present disclosure may use BLE as an illustrative example, although the present disclosure is applicable to wireless tags and testers that employ such other low-energy communication protocols.

[0035] Some BLE devices may include an Advanced RISC Machines (ARM) processor, such as IC 120, having at least one or more antennas, such as antenna 110, patterned or designed for transmitting (TX) and receiving (RX) data via radio frequency (RF) communication signals. Additional one or more antennas and other components may be included for harvesting energy, such as RF energy harvesting, to power the operation of the wireless tag. In other configurations, one or more antennas may be used for harvesting as well as TX and / or RX. Energy harvesting may allow the wireless tag to operate by charging a capacitor using an air signal without the need for a battery source or other external power source.

[0036] IC 120 also includes firmware or accessible storage devices for storing program code and data. Such firmware or program code is hereinafter referred to as code.

[0037] In some embodiments, a BLE low-cost device, such as wireless tag 100, is initially implemented on a reel or web, much like those commonly used in radio frequency identification (RFID) tags, so that there are multiple wireless tags arranged in an array. The array can be one-dimensional, such as a vector, or more typically, as a matrix, such as two-dimensional. The substrate of the BLE wireless tag is typically made of PET, PI or other flexible materials, and each antenna (such as antenna 110) is typically made of copper, aluminum or silver metal.

[0038] For the purpose of clarity of the present disclosure and teaching, it will be assumed hereinafter that the wireless tags are on a roll and have a two-dimensional matrix arrangement.

[0039] As part of the manufacture of each wireless tag 100, each IC 120 is initially manufactured as part of a wafer comprised of many ICs, each IC being referred to as a die. Figure 3 A wafer 351 is shown that includes multiple ICs or dies 120 arranged in a matrix. Each IC 120 is programmed with a unique identifier (ID) by burning the ID into the firmware of each corresponding IC 120. The location of each die on the wafer and the unique ID assigned to it are recorded. The location of each die in the wafer can be represented as an X, Y coordinate pair. This record can be stored locally or in the cloud. Therefore, the unique ID of each die can be mapped to the location of the die in the array, and vice versa.

[0040] Next, as is well known, using a pick and place machine, which is a robotic machine used to place surface mount devices at a specified location on a surface (such as a printed circuit board), each die 120 is removed from the wafer 351 and placed on a substrate of a wireless tag 100. In this case, the substrate can be considered an antenna mesh because it already contains at least one pre-printed antenna for use with the wireless tag. Arrows 353 indicate the location of several ICs 120.

[0041] Therefore, among various other processes, the assembly of the wireless tag may include connecting each die 120 (eg, using anisotropic conductive paste (ACP)) to an antenna on the wireless tag 100 substrate.

[0042] The position of each die 120 in the matrix is ​​recorded so that there is a correspondence between the position of each die 120 in the matrix and its original position in the wafer. Therefore, by converting from the position in the matrix (e.g., using a lookup) to the position in the wafer and thus to the unique ID, a unique ID for each die 120 in the matrix can be obtained.

[0043] Figure 4 It shows that Figure 3 4 shows an array of wireless tags 100 arranged in a matrix format, and also shows a unique identifier 435 for each wireless tag 100. As described above, the wireless tag 100 can be part of a tape or on a belt. Note that Figure 4 The number of columns suitable for a pick and place machine in one illustrative embodiment is shown. Of course, in various embodiments, this number may be different. Figure 4 The number shown is not the same as the number of rows shown, as it depends on the specific implementation of the pick and place machine. Note also that this number of columns can be different than the number of columns that the tester 200 can accommodate. The location of each die in the matrix can also be expressed as an X, Y coordinate pair, where X is the number of rows and Y is the number of columns. Typically, the range of X will be fixed to the number of rows in the matrix, e.g. Figure 3-Figure 5 The number of columns will depend on the length of the tape or band comprising the wireless tags.

[0044] It is possible to determine which wireless tags are in the tester based on knowing that at least one wireless tag in the first column enters the tester 200. Thus, all wireless tags in that column and subsequent columns can be determined from the recorded information. The movement of the wireless tag column only needs to be tracked by the tester 200.

[0045] In another embodiment, the pick and place machine prints the number of columns on at least one of the wireless tags in the matrix of wireless tags, which is sized to fit the test area. Based on this, it can be determined which wireless tags are in the tester because their positions are known from the pick and place machine. This enables the tester to use machine vision to identify which columns are in the matrix of the test area. The number of columns can be universally unique or unique to each net.

[0046] Figure 2 A schematic diagram of a tester 200 configured to test the functionality of a plurality of wireless tags, such as the wireless tag 100, according to an embodiment is shown. As described above, the wireless tag being tested (such as the wireless tag 100) may be a battery-free wireless tag that performs energy harvesting, such as harvesting energy from a wireless signal affecting it, as described above.

[0047] The tester 200 is configured to determine whether each of the plurality of wireless tags 100 within a test area of ​​the tester 200 operates as expected. The tester 200 may be integrated into a machine that assembles wireless tags or performs other manufacturing processes thereon.

[0048] The tester 200 includes a transmitter / receiver (TX / RX) 210 connected to a far-field antenna 201. The TX / RX 210 is further connected to a microcontroller (MC) 230.

[0049] TX / RX 210 is configured to transmit signals to multiple wireless tags 100 via antenna 201. Each wireless tag 100 is configured to use at least some of the transmitted signals to charge a capacitor (e.g., capacitor 130) via its acquisition antenna. The signal transmitted by TX / RX 210 may include any wireless signal that a wireless tag can receive, and may include wireless signals such as FM radio, cellular, LoRa, nRF, Etc. In one embodiment, the signal that each wireless tag 100 can collect need not be the same type of signal that it uses for communication.

[0050] TX / RX 210 may be configured to simultaneously transmit multiple different signals, such as a BLE signal and an FM radio signal, to the wireless tag 100, for example, to charge the wireless tag 100 using its various acquisition antennas. In the case where TX / RX 210 is configured to transmit signals in different frequency bands, TX / RX 210 may operate according to instructions received from the microcontroller 230 indicating which type of signals are to be transmitted to the wireless tag 100, and the time frame in which they are to be transmitted.

[0051] The wireless tags 100 are manufactured on a mass production level, and therefore testing of such wireless tags needs to be performed accurately on a large scale within acceptable time limits.

[0052] As is well known, for example, the Bluetooth LE specification starts at 2400MHz and divides the adopted communication bandwidth into 40 channels of 1MHz and 2MHz intervals. Three of these channels are called "advertising" channels and are used exclusively by devices to send beacon packets called advertising packets. These packets contain information that allows other devices to connect, and they can also provide information about the device. The advertising channels of BLE are channels 37, 38 and 39, i.e. CH37, CH38 and CH39. In normal operation, the advertiser sends three identical ADV_IND BLE packets sequentially through channels CH37, CH38 and CH39. This is called an advertising event, or advEvent for short. In response, the wireless tag will send a message containing its unique ID.

[0053] It is readily understood by those of ordinary skill in the art that in order to operate a battery-less wireless tag, charging (i.e., energization) is necessary. Even a wireless tag with a battery may require some degree of charging, for example, to provide sufficient power for operation when the battery has a small capacity, or to charge the battery. In an illustrative embodiment, energy at approximately 2480 MHz may be used to energize the wireless tag so that it can operate. In another embodiment with two different collectors, energy at approximately 2480 MHz may be used by one collector for charging, while energy at approximately 915 MHz may be used by another collector. In some embodiments, the transmitted beacon may also be used to energize the wireless tag.

[0054] In some embodiments, since the wireless tag may be battery-less, at least sometimes, such as every time, during normal operation, when the wireless tag wakes up from a fully off state, the wireless tag must calibrate itself. Therefore, when the wireless tag wakes up, it may have to perform calibration. This is typically done at least when the wireless tag changes from fully off to open. If the wireless tag is in a hold mode, the wireless tag may not need to perform calibration again, but can use previously stored calibration values. However, the wireless tag can perform calibration periodically to account for any changes in the environment.

[0055] Generally speaking, as long as the tester 200 receives the appropriate expected response from a tested wireless tag 100 in a timely manner, the wireless tag 100 is considered qualified and enters the next manufacturing step. However, when the tester 200 does not receive the correct expected response from the specific wireless tag 100 under test in a timely manner, the wireless tag 100 is considered bad and is designated for discard.

[0056] In some embodiments, before initiating transmission on each frequency, the wireless tag may calibrate its transmitter to the specific frequency it will be transmitting on. This is part of the calibration mentioned above, and must be completed successfully before the wireless tag can be considered operational.

[0057] Figure 5 Another view of an illustrative embodiment of a tester 200 according to an embodiment is shown. For example, as described above, in Figure 5 In an embodiment, the tester 200 sends an appropriate signal from the far-field antenna 201 to excite and prepare each wireless tag 100 within range of the antenna 201 to send a response signal including its unique ID. During the test, the antenna 201 can be above or below the IoT wireless tag 100. In one embodiment, the far-field antenna (e.g., antenna 201) is located "above" the wireless tag matrix 100 in the middle of the test area.

[0058] exist Figure 5In some embodiments, the wireless tags 100 are arranged in an array or matrix, which may be part of a belt or located on a belt (not shown) with other wireless tags 100, all of which may be movable in the direction indicated by arrow 509. The arrangement of the array and how many wireless tags may be in the test area at one time is determined by the implementer. However, it should be understood that in some embodiments, for example, Figure 5 As shown, the number of columns that can be accommodated in the test area of ​​the tester 200 can be different from the number of columns that can be processed in the placement area of ​​the pick and place machine that places the die 120 on the wireless tag 100, as described above with respect to Figure 4 For example, Figure 3 and Figure 4 As shown, the pick and place machine accommodates four columns, while e.g. Figure 5 As shown, tester 200 accommodates only three columns.

[0059] Since the testing is performed using the far field, in one embodiment, the testing can be performed in a shielded environment. An opening can be formed in the chamber formed by the various shielding portions so that radio waves can pass between the far field antenna 201 and the wireless tag 100, and the antenna transmits to and receives from the wireless tag 100. In some embodiments, the conveyor belt (if used) is non-conductive to minimize communication interference between the far field antenna 201 and each wireless tag 100. Controller ( Figure 5 ) can synchronize the movement of the wireless tag 100 with the test process, for example, a signal sent by the antenna 201 and expected to be received by the antenna 201.

[0060] In another embodiment, there is no need to test in a shielded environment because the tester knows which wireless tags are in the test area and therefore can ignore any transmissions from other wireless tags not in the test area because the other wireless tags are not being tested.

[0061] Each wireless tag 100 enters the test area when crossing the boundary 503, and therefore expects to receive a signal from the antenna 201. It may take hundreds of milliseconds for the wireless tag to power up and perform a full calibration.

[0062] according to Figure 5 In one implementation of the illustrated embodiment, all wireless tags 100 can be charged and calibrated substantially simultaneously. This can reduce the test time required to collectively test all wireless tags 100 within a test area relative to the prior art, because only one charging and calibration time is required to enable the wireless tags 100 within the test area to transmit, relative to each wireless tag 100 requiring its own charging time.

[0063] according to Figure 5In another implementation of the illustrated embodiment, the antenna 201 continuously transmits a beacon pattern, and then there is a silent period, i.e., a period when the antenna 201 does not transmit, so the wireless tags have many opportunities to power on and calibrate, and also many opportunities to transmit. Once all wireless tags 100 have entered the test area, those IoT wireless tags 100 that are farthest from the entrance to the test area have the best chance to charge, calibrate, and transmit. Therefore, they may be the first to complete calibration and send a response, thereby minimizing the number of conflicts in the response. Since the signal that causes the wireless tag to respond is sent in a repeated manner, there is no loss for wireless tags 100 that enter the test area later.

[0064] A group of wireless tags 100 is moved into the test area of ​​the tester 200. Once the group of wireless tags 100 that fill the test area of ​​the tester 200 is in the test area, the wireless tags can stop moving for a specified period of time. The antenna 201 sends a signal to stimulate the wireless tags 100 that fill the test area of ​​the tester 200. As described above, the signal can be sent repeatedly, so once the first column of wireless tags 100 of the group enters the test area, their transmission can begin.

[0065] The good wireless tags perform their calibration and attempt to send a response. To this end, in one embodiment, the wireless tags that are ready to respond first evaluate the channel conditions. When the wireless tag makes an assessment that the channel is clear, for example, it senses the channel and does not detect that the energy on the channel is above a specified threshold, it sends a response including a version of its unique ID. If the channel is not clear, the wireless tag waits a certain amount of time, for example based on a timer, and then repeats the process of checking the channel again. Ultimately, all normally operating wireless tags, i.e., good wireless tags, will send a signal including a version of their unique identifier (ID).

[0066] In some embodiments, the version of the unique ID is an encrypted version of the unique ID. When the version of the unique ID is an encrypted version of the unique ID, the encrypted ID can be decrypted by another system to which the encrypted version of the unique ID is sent. This other system can be remote from the tester, such as another computer or a cloud. The remote system returns the decrypted ID to the tester. The tester then uses a mapping of the decrypted unique ID to the wafer position, and then a mapping of the wafer position to the matrix position, to determine where the wireless tag is located in the test area of ​​the tester 200.

[0067] In another embodiment, the wireless tag may transmit first and then detect whether a collision exists, for example, using an ALOHA-type protocol.

[0068] The tester receives such transmitted signals, if any, from the wireless tags.

[0069] In one embodiment, the unique ID is not sent in encrypted form, and the tester 200 can proceed to determine the unique ID number of the wireless tags in the test area, that is, the unique ID number of the specific wireless tags that make up the group once the wireless tags that make up the group enter the test area. To do this, the tester 200 obtains an indication that enables it to determine the position of each die 120 in the matrix determined by the pick and place machine. Using each position, the tester 200 is able to use the recorded correspondence between the position of each die 120 in the matrix and its original position in the wafer. Knowing the position in the wafer, the unique ID can be retrieved based on the record consisting of the position of each die on the wafer and the unique ID assigned to it.

[0070] The wireless tags remain in the test area long enough so that all wireless tags have a chance to respond and transmit their IDs. The tester can compare the received IDs with the IDs of wireless tags known to be in the group and declare those tags that have received the IDs to be good and those that have not received the IDs to be bad. Because the tester knows the location of the wireless tags corresponding to each ID, the tester can mark those wireless tags that receive a valid response with the ID as good. In one embodiment, this can be accomplished by having the tester print an indication on the good wireless tags that the good wireless tags are good. In another embodiment, a file can be created that specifies the location of the good wireless tags. This can be used to ensure that the good wireless tags are saved.

[0071] Similarly, since the tester knows the location of the wireless tags corresponding to each ID, and therefore knows which wireless tags are in the group, the tester can mark the wireless tags that did not receive a valid response for the ID as bad tags. In one embodiment, this can be done by having the tester print an indication on the bad wireless tag itself that the bad wireless tag is bad. In another embodiment, a file specifying the location of the bad wireless tags can be created and used to discard the bad wireless tags later.

[0072] Figure 6 An illustrative process for testing a group of wireless tags by a tester, such as an embodiment of tester 200, is shown in flowchart form as performed by the tester.

[0073] When a group of wireless tags (e.g., a group of wireless tags 100) moves into a test area (e.g., within the antenna range of a tester), the process is entered in S601. For example, the wireless tags may be brought within the range of antenna 201 of tester 200 ( Figure 3 ). This can be achieved by moving a conveyor belt or a wireless tag belt. Once the group of wireless tags 100 that fill the test area of ​​the tester 200 is in the test area, the wireless tags can stop moving within a specified time period.

[0074] Then, in S603, the tester determines which wireless tags 100 are in the group, i.e., the unique IDs of the wireless tags in the group. This is based on the recorded position of each die 120 in the matrix, and uses the correspondence between the position of each die 120 in the matrix and its original position in the wafer. Therefore, for each die 120 in the matrix in the tester, it can be obtained by converting from the position in the matrix (e.g., using a lookup) to the position in the wafer and thus to a unique ID. Machine vision can be used to help determine which columns are in the matrix in the test area, for example, by reading at least one column number printed on at least one wireless tag in the matrix by a pick and place machine.

[0075] Thereafter, in S605, the tester sends a repeated beacon in the far field. For example, the repeated beacon can be sent by the antenna 201 of the tester 200 ( Figure 5 ). The transmission of beacons is alternated with periods of silence so that the wireless tags have an opportunity to transmit.

[0076] Next, the tester waits and receives any responses from the wireless tags in S607. In one embodiment, this waiting is performed for a specified time. In another embodiment, if responses are received from all wireless tags known in the tester, the waiting ends before the specified time ends.

[0077] Conditional branch point S609 is executed at the end of the wait in S607 and tests to determine whether a timely response has been received (eg, via antenna 201 ) for each wireless tag known to be in the test area.

[0078] If the test result in S609 is yes, then for each wireless tag that receives a valid response in time, control is transferred to S611, in which the wireless tag that receives a valid response in time is declared good. Then, control is transferred to S613, in which the wireless tag is specified for the next manufacturing stage. This can be achieved by marking a record for each such wireless tag in the memory of the tester. In addition, the test unit may have printing capabilities and, if necessary, can appropriately print a visual indication of pass or fail on each wireless tag itself. For example, this next stage can be a conversion. Then, control is transferred to S615, and when there is a group of wireless tags that have not received a valid response, S615 is performed only when steps 617 and 619 have been performed, and the group of wireless tags is moved out of the test area.

[0079] If the test result in S609 is no, indicating that for at least some of the wireless tags in the group of wireless tags, a valid response was not received in time, then control is transferred to S617, in which each such wireless tag is declared bad. Control is then transferred to S619, in which such wireless tags are designated for discard. This can be achieved by marking a record of the wireless tags to be discarded in the memory of the tester. Then, control is transferred to S615, and when there is a group of wireless tags that received a valid response, S615 is executed only when steps 611 and 613 have been executed, and the group of wireless tags is removed from the test area.

[0080] Figure 7 An illustrative process for establishing a relationship between a die's location in the matrix and its unique ID is shown in flow chart form.

[0081] When a wafer with multiple dies is received, the process starts at S701. In S703, a unique ID is burned into each die.

[0082] Next, in S705, the position of the die on the wafer is recorded, which is associated with the unique ID burned on the wafer. Then, in S707, the pick and place machine places each die on the wireless tag substrate in the matrix. In S709, the position of each wireless tag placed in the matrix is ​​recorded.

[0083] Figure 8 For example, the MC 230 ( Figure 2 )) or a wireless tag (e.g., IC 120 ( Figure 1 )) is a more detailed diagram of an illustrative arrangement 800 of a controller of an embodiment of the present invention. The arrangement 800 includes a processing circuit 810 coupled to a memory 820, a storage device 830, and a network interface 840 coupled to at least an antenna arrangement 860. In an embodiment, the components of the arrangement 800 may be communicatively connected via a bus 850.

[0084] Processing circuit 810 may be implemented as one or more hardware logic components and circuits. For example, but not limited to, illustrative types of hardware logic components that may be used include field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), system-on-a-chip systems (SOCs), general-purpose microprocessors, microcontrollers, digital signal processors (DSPs), etc., or any other hardware logic components that can perform calculations or other information operations. Figure 8 When the arrangement is part of a wireless tag (e.g., wireless tag 100), the processing circuit 810 may at least partially implement the integrated circuit 120 ( Figure 1 ), and when Figure 8 When the arrangement is part of a tester, the processing circuit 810 may at least partially implement the MC 230 ( Figure 2 ).

[0085] The memory 820 may be volatile (e.g., random access memory (RAM), etc.), non-volatile (e.g., read-only memory (ROM), flash memory, etc.), or a combination thereof. In one configuration, computer-readable instructions implementing one or more embodiments disclosed herein may be stored in the storage device 830.

[0086] In another embodiment, the memory 820 is configured to store software. Software should be broadly interpreted as any type of instructions, whether referred to as software, firmware, middleware, microcode, hardware description language or other. Instructions may include code in source code format, binary code format, executable code format, or any other suitable code format. When executed by the processing circuit 810, these instructions cause the processing circuit 810 to perform the various processes described herein. Specifically, these instructions, when executed, cause the processing circuit 810 to create, generate, and manage the operation of the wireless tag or tester as described above.

[0087] The storage device 830 may be a magnetic storage device, an optical storage device, etc., and may be implemented as, for example, a flash memory or other storage technology, a CD-ROM, a digital versatile disk (DVD), or any other medium that can be used to store the required information. The storage device 830 may be optional.

[0088] When implemented by arrangement 800, network interface 840 allows a tag or tester to communicate with other elements external to arrangement 800. Network interface 840 may include a radio frequency module for wireless communication via antenna arrangement 860, which may include one or more antennas. When arrangement 800 is employed to implement a tester, network interface 840 may also interface with other components, such as components that move a wireless tag or control the position of a wireless tag or change the position of an antenna.

[0089] Antenna arrangement 860 represents any antenna architecture implemented for a wireless tag or tester. As described above, it can be one antenna or more than one antenna. Antenna arrangement 860 primarily represents one or more antennas for wireless communication, but it does not exclude the use of any of its antennas for energy harvesting or providing energy for energy harvesting. Although not shown in arrangement 800, arrangement 800 may include additional antennas and circuits for energy harvesting.

[0090] It should be understood that the embodiments described herein are not limited to Figure 8 While specific architectures are shown, other architectures may equally be used without departing from the scope of the disclosed embodiments.

[0091] The various embodiments disclosed herein may be implemented as hardware, firmware, software executable on hardware, or any combination thereof. In addition, the software is preferably implemented as an application program tangibly contained in a program storage unit or a computer-readable medium, which is composed of a part or some devices and / or a combination of devices for being executed by hardware. The application program can be uploaded to a machine including any suitable architecture and executed by the machine. Preferably, the machine is implemented on a computer platform (having hardware such as one or more central processing units ("CPU"), memory, and input / output interfaces). The computer platform may also include an operating system and microinstruction codes. The various processes and functions described herein may be parts of microinstruction codes or parts of application programs, or any combination thereof, which may be executed by a CPU, whether or not such a computer or processor is explicitly shown. In addition, various other additional units may be connected to a computer platform, such as additional data storage units and printing units. In addition, a non-transitory computer-readable medium is any computer-readable medium other than a temporary propagation signal.

[0092] All examples and conditional language described herein are intended for teaching purposes to help the reader understand the principles of the disclosed embodiments and the concepts contributed by the inventors to promote technological development, and should be understood as not being limited to such specifically enumerated examples and conditions. In addition, all statements of the principles, aspects, and embodiments of the disclosed embodiments described herein and their specific examples are intended to cover their structural and functional equivalents. In addition, it is intended that such equivalents include currently known equivalents and equivalents developed in the future, that is, any element developed to perform the same function, regardless of structure.

Claims

1. A method for testing a wireless tag by a testing unit, comprising: sending a signal that substantially simultaneously excites a plurality of wireless tags within a test area of ​​the test unit; waiting a specified amount of time, the waiting specified amount of time being sufficient to allow all of the wireless tags in the test area to have an opportunity to respond with a transmitted message, each transmitted message including a unique identifier of the wireless tag; Based on information about the identities of those wireless tags in the test area and the sent messages (if any) received by the tester from the wireless tags in the test area containing their respective unique identifiers, determine which of the multiple wireless tags are good and which of the multiple wireless tags are bad.

2. The method according to claim 1, wherein: The unique identifier is encrypted, further comprising decrypting the encrypted unique identifier.

3. The method according to claim 2, wherein: Decrypting the encrypted unique identifier also includes sending the encrypted unique identifier to a system remote from the test unit.

4. The method according to claim 1, wherein: Signals that excite the plurality of wireless tags are transmitted in the far field.

5. The method according to claim 1, wherein: Signals energizing the plurality of wireless tags are repeatedly transmitted in a pattern alternating with silent periods to allow transmissions by the wireless tags.

6. The method according to claim 1, wherein: When a transmitted message is received from the wireless tag within the prescribed amount of time, a wireless tag among the plurality of wireless tags is determined to be good.

7. The method according to claim 1, wherein: When a transmitted message is not received from the wireless tag within the prescribed amount of time, a wireless tag among the plurality of wireless tags is determined to be bad.

8. The method of claim 1, further comprising determining which wireless tags are among the plurality of wireless tags.

9. The method according to claim 1, wherein: At least some information about the identity of those wireless tags in the test area is provided by a pick-and-place machine, and the at least some information associates the position of each die on the wafer with the position where the pick-and-place machine places each die in a substrate matrix of wireless tags, and the wafer position of each die is associated with the unique identifier of the die.

10. The method according to claim 1, further comprising printing, by the test unit, an indication that the wireless tag is good on the wireless tag determined to be good.

11. The method according to claim 1, further comprising printing, by the test unit, an indication that the wireless tag is bad on the wireless tag determined to be bad.

12. The method according to claim 1, wherein: The plurality of wireless tags are arranged in a matrix, and wherein information about the identities of those wireless tags in the test area is determined by converting the position of at least one wireless tag in the matrix to the original position of the at least one wireless tag in the wafer.

13. The method according to claim 1, wherein: At least one wireless tag in the test area is identified using machine vision of indications printed on the at least one wireless tag.

14. The method of claim 1, further comprising moving the plurality of wireless tags into the testing area.

15. A method for testing a wireless tag by a testing unit, comprising: Determining which, if any, of the plurality of wireless tags in the test area are good based on responses received from one or more of the plurality of wireless tags in response to at least one excitation signal sent in the test area and information regarding which wireless tags constitute the plurality of wireless tags in the test area.

16. The method according to claim 15, wherein: The excitation signal is transmitted in a far field to be received by wireless tags of the plurality of wireless tags substantially simultaneously.

17. The method according to claim 15, wherein: The excitation signal is repeatedly transmitted in a pattern alternating with silent periods to allow transmission by the wireless tags.

18. The method according to claim 15, wherein: Also included is determining which, if any, of the plurality of wireless tags in the test area are bad based on responses received from one or more of the plurality of wireless tags in response to at least one excitation signal and information regarding which wireless tags constitute the plurality of wireless tags in the test area.

19. The method according to claim 15, further comprising: moving the plurality of wireless tags into the testing area; waiting a specified amount of time, the specified amount of time being sufficient for each wireless tag to respond to the at least one excitation signal with a transmitted message, each transmitted message including a unique identifier of the wireless tag; Based on information about the identities of those wireless tags in the test area and the sent messages (if any) received by the tester from the wireless tags in the test area containing their respective unique identifiers, determine which of the multiple wireless tags are good and which of the multiple wireless tags are bad.

20. The method according to claim 15, wherein: Each received response includes a unique identifier of those of the plurality of wireless tags that sent the response, and each unique identifier can be converted into a position in the matrix in which the plurality of wireless tags are arranged.

21. The method according to claim 15, wherein: Each received response includes an encrypted version of a unique identifier of those of the plurality of wireless tags that sent the response, each unique identifier being convertible to a position in a matrix in which the plurality of wireless tags are arranged, the method further comprising: sending each encrypted version with the unique identifier to a remote system; and A decrypted version of each encrypted version sent with the unique identifier is received.

22. The method according to claim 15, wherein: At least a portion of the message regarding which wireless tags constitute the plurality of wireless tags in the test area is based on information provided by a pick-and-place machine associating the location of each die on the wafer with a location in a wireless tag substrate matrix where the pick-and-place machine places each die, the wafer location of each die being associated with a unique identifier of the die.

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