Wafer sorting management method based on RFID tags

Abstract

The application discloses a wafer sorting management method based on an RFID label and relates to the technical field of semiconductors. The method sets a wafer RFID label on a wafer and prewrites wafer information, additionally sets an RFID reader at a corresponding station of a sorting machine, reads the RFID label in a wafer tray by using the RFID reader when wafer feeding is performed, and performs consistency comparison on information of a Bin value, a wafer ID and a wafer storage position. After threefold verification, the wafer is extracted and chip sorting is performed. By binding wafer inherent information by using the RFID label and combining with real-time reading and writing verification of the station, the method can effectively avoid problems of wrong chip mounting and mixed mounting, is favorable for information summarization and management in the sorting process, and is favorable for improving wafer sorting accuracy and sorting efficiency.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to a wafer sorting and management method based on RFID tags. Background Technology

[0002] Wafer sorting is a critical step in the semiconductor processing. Its main purpose is to sort chips of different grades (Bin values) on the wafer into different wafers based on the electrical test results from the wafer testing stage, in preparation for subsequent packaging.

[0003] Wafer sorting is performed by a sorting machine. The operator places wafer cassettes on the sorting machine's loading station, and the sorting machine loads the wafers from the cassettes. The operator uses the sorting machine's barcode scanner to scan the wafer's serial number (SN code). The sorting machine's control system reads the wafer's mapping map from the MES (Manufacturing Execution System) according to the wafer's serial number to determine the coordinates of each chip within the wafer and its tested Bin value. Then, chips with different Bin values ​​are picked up from the wafer and placed into different wafers. Chips with the same Bin value are placed into the same wafer, and chips with different Bin values ​​are placed into different wafers. Each wafer contains only one type of chip with a specific Bin value. In actual sorting scenarios, multiple wafers often need to be sorted, and a single wafer often contains multiple chips with different Bin values. This can easily lead to chip missorting and mixing, affecting sorting accuracy and effectiveness, and consequently impacting subsequent processing. Summary of the Invention

[0004] This application addresses the aforementioned problems and technical requirements by proposing a wafer sorting and management method based on RFID tags. The technical solution of this application is as follows:

[0005] A wafer sorting and management method based on RFID tags, the wafer sorting and management method comprising: The sorting record is queried according to the received sorting instruction. The sorting instruction indicates the target Bin value to be sorted. The sorting record records the sorting entries for each piece in the unloading bin. Each piece sorting entry records the piece information and chip loading information of the current piece. The piece information includes the piece ID, the piece storage location in the unloading bin, and the corresponding Bin value. The non-conductive area of ​​each piece in the unloading bin is fixed with a piece RFID tag and the piece information is pre-written. Based on the material sorting entries of each material in the sorting record, select the material corresponding to the target Bin value in the sorting instruction as the target material, and read the target material ID and target material storage location from the sorting record; The RFID reader at the material loading station of the sorting machine is used to read the material information in the RFID tag of the material at the storage location of the target material; When the chip ID in the chip information of the chip at the target chip storage location matches the target chip ID, the target chip at the target chip storage location in the lower hopper is extracted and pushed to the sorting machine's worktable. Chips with the target Bin value in the current wafer are sorted into the target chips, and the sorting record is dynamically updated during the sorting process.

[0006] The further technical solution is that the chip loading information of each chip includes real-time loading status and loading attribute parameters. The real-time loading status is empty, partially loaded or fully loaded. The real-time loading status of each chip is initialized to empty. Based on the material sorting entries in the sorting record, select a material piece corresponding to the target Bin value as the target material piece, and dynamically update the sorting record during the sorting process, including: When a wafer with the target Bin value and in a partially loaded state exists in the sorting record, the wafer with the target Bin value and in a partially loaded state is taken as the target wafer; otherwise, one of the wafers with the target Bin value and in an unloaded state is taken as the target wafer. The loading attribute parameters of the target wafer are read from the sorting record, and the chips with the target Bin value in the current wafer are sorted into the target wafers according to the loading attribute parameters of the target wafers, and the chip loading information of the target wafers is dynamically updated.

[0007] The further technical solution involves assigning loading attribute parameters for each wafer, including the number of loaded chips, maximum loading quantity, chip loading row and column specifications, and the row and column coordinates of the last chip on the wafer. Based on the loading attribute parameters of the target wafer, chips with the target Bin value in the current wafer are sorted into the target wafer, and the chip loading information of the target wafer is dynamically updated, including: Based on the chip loading row and column specifications and the row and column coordinates of the last chip on the target wafer, the chips with the target Bin value in the current wafer are loaded onto the target wafer in sequence, and arranged in rows and columns starting from the next row and column coordinate of the last chip on the target wafer. When the number of chips loaded in the target wafer reaches the maximum loading quantity, the target wafer is placed back in the target wafer storage location, the real-time loading status of the target wafer in the sorting record is updated to full load status, and the loading attribute parameters of the target wafer in the sorting record are updated; if there are still unsorted chips with target Bin values ​​in the current wafer, the step of selecting one of the wafers with the target Bin value and in an unloaded state as the target wafer is re-executed. When all chips with the target Bin value in the current wafer are loaded into the target wafer, and the number of chips loaded in the target wafer has not yet reached the maximum loading quantity, the target wafer is placed back into the target wafer storage location. The real-time loading status of the target wafer in the sorting record is kept in a partially loaded state or updated from an empty state to a partially loaded state, and the loading attribute parameters of the target wafer in the sorting record are updated.

[0008] A further technical solution is that the wafer sorting management method also includes: The RFID reader at the wafer loading station of the sorting machine reads the wafer information in the wafer RFID tag of the current wafer. Each wafer has a fixed wafer RFID tag in the non-conductive area and the wafer information is pre-written. The wafer information includes the wafer serial number and wafer attribute parameters. The wafer attribute parameters include the total number of chips, the list of Bin values ​​containing chips, the wafer warehouse ID of the wafer warehouse to which the wafer belongs, and the production batch information. The current wafer's mapping map is read based on its serial number. The chips on the current wafer are sorted according to the current wafer's mapping map, and the real-time sorting status statistics are displayed based on the wafer's attribute parameters.

[0009] The further technical solution is that the wafer information for each wafer also includes wafer specifications, and the wafer sorting and management method also includes: The size detection sensor at the wafer loading station of the sorting machine detects the actual specifications of the wafer at the target wafer storage location. When the wafer ID in the wafer information at the target wafer storage location matches the target wafer ID, and the actual specifications of the wafer at the target wafer storage location match the wafer specifications of the current wafer, the target wafer at the target wafer storage location is extracted from the unloading bin and pushed to the sorting machine's worktable; otherwise, loading is stopped and an alarm is triggered.

[0010] A further technical solution is that the wafer sorting management method also includes: Based on the received sorting instructions, the target wafer warehouse ID and its storage location are determined. The AGV is controlled to move to the target wafer warehouse storage location, and the RFID reader on the AGV reads the wafer warehouse ID from the wafer warehouse RFID tag at the target wafer warehouse storage location. Each wafer warehouse has a fixed wafer warehouse RFID tag with pre-written wafer warehouse information. The wafer warehouse information for each wafer warehouse includes the wafer warehouse ID and wafer warehouse parameters. The wafer warehouse parameters include the total number of wafer warehouse layers, the effective number of wafer layers arranged in the wafer warehouse, and product attribute information. The product attribute information includes the total number of chips in the wafer warehouse, the Bin value list, and the production batch information. When the wafer warehouse ID in the wafer warehouse RFID tag at the target wafer warehouse storage location matches the target wafer warehouse ID, the AGV is controlled to transport the wafer warehouse at the target wafer warehouse storage location to the wafer warehouse placement platform of the sorting machine. The RFID reader at the wafer warehouse placement platform of the sorting machine reads the wafer warehouse information from the wafer warehouse RFID tag. According to the wafer warehouse information, each wafer in the wafer warehouse is loaded and sorted in sequence. Real-time sorting status statistics are obtained based on the wafer warehouse parameters and displayed in real time.

[0011] The further technical solution is that the storage location of the target wafer includes the target unloading bin ID of the unloading bin where the target wafer is located and the target layer number of the target wafer within the unloading bin. Several unloading bins are placed at the unloading bin placement platform of the sorting machine. The wafer sorting management method also includes: The RFID reader at the material loading station of the sorting machine is used to read the material loading RFID tag information of each material loading bin. The material loading information of each material loading bin includes the material loading bin ID and material loading bin attribute parameters. The material loading bin attribute parameters include the total number of layers in the material loading bin, the effective number of material loading layers in the material loading bin, and the production batch information. If the effective number of material layers arranged in the feeding bin with the same ID as the target feeding bin includes the target number of layers, then the material layer with the target number of layers in the feeding bin with the target feeding bin ID is determined as the target material; otherwise, an alarm is triggered.

[0012] A further technical solution involves attaching RFID tags to the wafer tray frame. The wafer sorting and management method also includes: The chip loaded on the sheet is ejected at the sorting machine's discharge station. The RFID reader at the sorting machine's discharge station erases the sheet information from the RFID tag, discards the blue film of the sheet, and recycles the tray frame. The recycled material tray frame is fitted with a new blue film to obtain brand new material pieces. The RFID reader at the sorting machine's warehousing station is used to write the new material piece information into the material piece's RFID tag. After writing, the material piece is placed in the corresponding material piece storage location in the unloading hopper, and a new material piece sorting entry for the current material piece is added to the sorting record. The material piece information is written into the corresponding material piece sorting entry, and the chip loading information is initialized.

[0013] A further technical solution involves embedding a breakpoint antenna between each RFID tag and its adhesive surface. The breakpoint antenna breaks the circuit and disables the RFID tag when it is separated from the adhesive surface. The RFID tag can only be encrypted and read / written by RFID readers with modification permissions.

[0014] The further technical solution is that each RFID tag adopts an ultra-high frequency passive RFID tag with a ceramic substrate or flexible FPC anti-metal, and has ±10KV anti-static capability.

[0015] The beneficial technical effects of this application are: This application discloses a wafer sorting and management method based on RFID tags. The method involves setting RFID tags on wafers and pre-writing wafer information, and adding RFID readers to the corresponding workstations of the sorting machine. During the sorting process, when loading wafers, the RFID readers are used to read the RFID tags in the tray and compare the consistency of information such as Bin value, wafer ID, and wafer storage location. Only after passing the triple verification is the wafer extracted and chip sorted. By binding the inherent information of the wafer to the RFID tags and combining it with real-time read and write verification at the workstation, the problem of incorrect or mixed chip assembly can be effectively avoided. It is also beneficial to the information collection and management of the sorting process, and can improve the accuracy and efficiency of wafer sorting.

[0016] This method also involves attaching a wafer RFID tag to the wafer and writing wafer information onto it. During the wafer loading stage, this information is also verified before operation. Furthermore, the wafer information includes wafer specifications, allowing for a double check of the actual wafer specifications and the wafer specifications during the wafer loading stage, thus avoiding processing risks caused by mixing non-compliant wafers.

[0017] The method further sets up corresponding RFID tags on the wafer warehouse and unloading warehouse to record storage information, and sets up RFID tags at multiple workstations to read information, which facilitates real-time tracking of the sorting process and positioning of the sorting path, and facilitates supervision and traceability of the sorting process.

[0018] The RFID tags used in this application are all UHF passive RFID tags made of ceramic substrate or flexible FPC anti-metal, and have ±10KV anti-static capability. They require no modification to the cleanroom environment, have strong compatibility, and can address practical risks in mass production. Furthermore, authorized encrypted reading and writing between the RFID tags and the RFID reader / writer prevents information tampering and improves data security. Attached Figure Description

[0019] Figure 1 This is an application scenario diagram of a wafer sorting and management method in one embodiment of this application.

[0020] Figure 2 This is a schematic flowchart of a wafer sorting and management method in one embodiment of this application. Detailed Implementation

[0021] The specific embodiments of this application will be further described below with reference to the accompanying drawings.

[0022] This application discloses a wafer sorting management method based on RFID tags. This wafer sorting management method is applied in a sorting machine and can be implemented by the sorting machine control system. However, this method also requires an upgrade to the hardware structure of the sorting system. The hardware upgrade includes two aspects: setting RFID tags on the core components of the sorting system to record relevant information of the core components, and setting RFID readers / writers at the corresponding workstations of the sorting machine to read and write the RFID tags of the corresponding core components during the sorting process, thereby realizing information verification and flow control during the sorting process. These are described in detail below: 1. An RFID tag is fixed to the non-conductive area of ​​each material piece, and an RFID reader is installed at the material loading station of the sorting machine to ensure that the material pieces are pulled reasonably during the sorting process and to avoid missorting, mixing and other situations.

[0023] Please refer to Figure 1 The diagram illustrates an application scenario for a sorting machine. During sorting, the machine loads wafers 30 from wafer bins 20 on wafer bin placement platform 10 onto the worktable. Then, according to received sorting instructions, it sequentially loads the required wafers 60 from unloading bins 50 on unloading bin placement platform 40 onto the worktable, sorting chips of each Bin value on the wafers 30 into their respective wafers 60. In practical applications, one wafer bin 20 is placed on wafer bin placement platform 10 at a time, and the next wafer bin is replaced after sorting. Multiple unloading bins 50 are typically placed on unloading bin placement platform 40 simultaneously.

[0024] To ensure that the sheet material fed to the workbench is the correct one, this application sets an RFID tag 61 on each sheet material 60, and pre-writes the sheet material information into the RFID tag. The sheet material information includes the sheet material ID, the sheet material storage location in the unloading bin, and the corresponding Bin value. The sheet material ID is used to uniquely identify a sheet material, and the corresponding Bin value is pre-assigned. In one embodiment, the sheet material storage location in the unloading bin includes the unloading bin ID of the unloading bin where the sheet material is located, and the layer number of the unloading bin where the sheet material is located. The unloading bin ID is used to uniquely identify an unloading bin.

[0025] In addition, this application also maintains sorting records in real time. These sorting records record the sorting entries for each piece of material in the hopper. Each sorting entry for each piece of material records the material information and chip loading information of the current piece of material. The chip loading information indicates the current chip loading status in real time.

[0026] After receiving the sorting instructions, please refer to... Figure 2The flowchart shown first queries the maintained sorting records according to the sorting instructions. The sorting instructions indicate the target Bin value to be sorted. Based on the sorting entries of each piece in the sorting records, a piece corresponding to the target Bin value in the sorting instructions is selected as the target piece. The target piece ID and target piece storage location of the target piece are then read from the sorting records.

[0027] After reading the target material storage location, the material at the target material storage location is not directly collected as the target material. Instead, an automated information verification step is added. First, the RFID reader set at the material loading station of the sorting machine is used to read the material information in the RFID tag of the material at the target material storage location and compare it with the target material ID of the target material.

[0028] When the chip ID in the chip information at the target chip storage location matches the target chip ID, it means that the triple verification of Bin value, chip ID, and chip storage location has passed. The target chip at the target chip storage location in the lower hopper is then extracted and pushed to the sorting machine's worktable. Chips with the target Bin value in the current wafer are then sorted into the target chip, and the sorting record is dynamically updated during the sorting process. If the chip ID in the chip information at the target chip storage location does not match the target chip ID, it indicates a system error, and an alarm is triggered promptly to prevent sorting errors.

[0029] In one embodiment, the chip loading information for each wafer includes real-time loading status and loading attribute parameters. The real-time loading status of a wafer is either empty, partially loaded, or fully loaded. A wafer is in an empty state when no chips are loaded; in a partially loaded state when chips are loaded but not fully loaded; and in a fully loaded state when chips are loaded and fully loaded. The real-time loading status of each wafer is initialized to an empty state. Therefore, when selecting a target wafer based on the wafer sorting entries in the sorting record: First, the sorting record is checked to see if there is a piece that corresponds to the target Bin value and is in a partially loaded state. If there is a piece that corresponds to the target Bin value and is in a partially loaded state, it is prioritized as the target piece, meaning it is sorted into the loaded but not fully loaded piece category. If there is no piece that corresponds to the target Bin value and is in a partially loaded state, one of the pieces that corresponds to the target Bin value and is in an empty state is selected as the target piece.

[0030] It should be noted that this application pre-assigns a corresponding Bin value to each piece, thus showing that even pieces in an unloaded state have a corresponding Bin value. In practical applications, it is also possible not to pre-assign Bin values ​​to empty pieces. In this case, if there is no piece in the sorting record that corresponds to the target Bin value and is in a partially loaded state, an unloaded piece can be randomly selected as the target piece. However, this approach requires further writing the corresponding Bin value into the RFID tag of the target piece after selection, which is not ideal in practical applications. Therefore, this application adopts the method of pre-assigning Bin values ​​to the pieces.

[0031] After the target wafer is determined, in addition to reading the target wafer ID and target wafer storage location from the sorting record, the loading attribute parameters of the target wafer can also be read. When sorting the chip with the target Bin value in the current wafer into the target wafer, the sorting will be carried out according to the loading attribute parameters of the target wafer, and the chip loading information of the target wafer will be dynamically updated during the sorting process.

[0032] In one embodiment, the loading attribute parameters of each wafer include the number of loaded chips, the maximum number of chips loaded, the chip loading row and column specifications, and the row and column coordinates of the last chip on the wafer. The maximum number of chips loaded and the chip loading row and column specifications of each wafer are fixed, while the number of loaded chips and the row and column coordinates of the last chip on the wafer need to be updated dynamically. The number of loaded chips of a wafer in an unloaded state is 0, and the row and column coordinates of the last chip on the wafer can be initialized to empty.

[0033] When sorting chips with the target Bin value in the current wafer into the target wafer according to the loading attribute parameters of the target wafer, the chips with the target Bin value in the current wafer are loaded onto the target wafer in sequence based on the chip loading row and column specifications and the row and column coordinates of the last chip on the target wafer, and are arranged in rows and columns starting from the next row and column coordinate of the last chip on the target wafer.

[0034] When the number of chips loaded in the target wafer reaches the maximum loading capacity, the target wafer is placed back into its storage location. The real-time loading status of the target wafer in the sorting record is updated to full load, and the loading attribute parameters of the target wafer in the sorting record are also updated. If there are still unsorted chips with target Bin values ​​in the current wafer, the step of selecting one of the wafers with the target Bin value that is in an unloaded state as the target wafer is repeated. The next target wafer is then selected, and the above process is repeated to sort the remaining chips with target Bin values ​​in the current wafer into the next target wafer.

[0035] When all chips with the target Bin value in the current wafer are loaded into the target wafer, and the number of chips loaded in the target wafer has not yet reached the maximum loading quantity, the target wafer is placed back into the target wafer storage location. The real-time loading status of the target wafer in the sorting record is set to partially loaded, and the loading attribute parameters of the target wafer in the sorting record are updated: Before loading chips from the current wafer, the real-time loading status of the target wafer may be either empty or partially loaded. Therefore, when setting the real-time loading status of the target wafer to partially loaded, the real-time loading status of the target wafer in the sorting record is kept at partially loaded or updated from empty to partially loaded.

[0036] By using RFID tags carried by the material pieces to record material information, and combining this with the maintained sorting records, automated information verification can be performed during the sorting process. This avoids sorting errors or inefficiencies in scenarios without verification or manual verification, making it more suitable for error-proofing measures in automated operations.

[0037] Furthermore, the wafers are typically made by combining a tray frame with a blue film. In practical applications, the tray frame is generally reused. Therefore, in another embodiment, the wafer RFID tag is affixed to the tray frame. When the tray frame is made of metal (such as the commonly used stainless steel), the RFID tag is attached to the tray frame with insulating tape. Additionally, RFID readers are added to the discharge and receiving stations of the sorting machine. After the chip loading on the wafer is ejected at the discharge station of the sorting machine, the RFID reader at the discharge station erases the wafer information from the RFID tag, discards the blue film of the wafer, and recovers the tray frame and the RFID tag attached to it.

[0038] When reusing the material tray frame, a new blue film is installed on the recycled material tray frame to obtain brand new material pieces. Then, the RFID reader at the sorting machine's warehousing station is used to write the new material piece information into the material piece's RFID tag. After writing, the material piece is placed into the corresponding material piece storage location in the unloading hopper to realize warehousing. The current material piece sorting entry is added to the sorting record, the material piece information is written into the corresponding material piece sorting entry, and the chip loading information is initialized.

[0039] Second, a wafer RFID tag 31 is fixed in the non-conductive area of ​​each wafer 30, and an RFID reader is also set at the wafer loading station of the sorting machine to ensure the accuracy of wafer loading and information tracking.

[0040] As mentioned above, when the sorting machine performs the sorting operation, it loads wafers from the wafer bins at the wafer bin placement platform onto the worktable. Therefore, whether the loading is accurate according to the sorting instructions directly affects the subsequent sorting process. To ensure loading accuracy, in this embodiment, each wafer is also equipped with a wafer RFID tag. The wafer RFID tag is pre-written with wafer information, including a wafer serial number (SN code) and wafer attribute parameters. The wafer attribute parameters include the total number of chips contained in the wafer, a list of Bin values ​​for the chips contained in the wafer, the wafer bin ID to which the wafer belongs, and production batch information, such as batch number and / or work order number. The wafer serial number is used to uniquely identify a wafer, and the wafer bin ID is used to uniquely identify a wafer bin.

[0041] When loading wafers from the wafer warehouse onto the worktable, the RFID reader at the wafer loading station of the sorting machine is first used to read the wafer information in the wafer RFID tag of the current wafer. Each wafer has a fixed wafer RFID tag in the non-conductive area and the wafer information is pre-written. The wafer information includes the wafer serial number and wafer attribute parameters. The wafer attribute parameters include the total number of chips, the list of Bin values ​​containing the chips, the wafer warehouse ID to which the wafer belongs, and the production batch information.

[0042] The system reads the current wafer's mapping map based on its serial number, sorts the chips on the wafer according to the map, and displays real-time sorting status statistics based on wafer attribute parameters to dynamically show the sorting progress. The real-time sorting status statistics include not only wafer attribute parameters but also the total number of chips sorted on the wafer, the number of chips with each Bin value sorted, the current Bin value being sorted, and the wafer ID of the wafer used to load chips with each Bin value, facilitating dynamic management of the sorting process.

[0043] Furthermore, sorting machines handle wafers / wafers of different sizes during sorting, such as the common 8-inch and 6-inch wafers. The wafers loaded and the wafers unloaded may have different sizes; for example, the loaded wafers might be 8-inch while the unloaded wafers might be 6-inch. Mixing different sizes does not pose a risk during the sorting stage, but problems often arise in the next process using wafers of different shapes and sizes. Therefore, to avoid the risks associated with mixing different sizes, each wafer's information includes its wafer size. Additionally, size detection sensors (such as laser displacement sensors) are installed at the wafer loading station of the sorting machine. The RFID reader at the wafer loading station of the sorting machine can also read the current wafer size. When extracting the target wafer from the unloading hopper, the size detection sensor at the wafer loading station of the sorting machine is used to detect the actual specifications of the wafer at the target wafer storage location. When the wafer ID in the wafer information at the target wafer storage location matches the target wafer ID, and the actual specifications of the wafer at the target wafer storage location match the wafer specifications of the current wafer, that is, when the triple verification of Bin value-wafer ID-wafer storage location is confirmed to be passed and the specification verification is passed, the target wafer at the target wafer storage location in the unloading hopper is finally extracted and pushed to the sorting machine's worktable; otherwise, loading is stopped and an alarm is triggered to avoid wafer damage caused by incorrect tray size.

[0044] Third, in addition to setting RFID tags on wafers and wafers, RFID tags are also set on wafer silos and unloading silos to facilitate trajectory tracking of the entire sorting process and to facilitate AGV collaboration and unmanned docking.

[0045] In real-world applications, multiple wafer bins are placed on shelves. These bins are similar in appearance and easily confused. To facilitate differentiation between different wafer bins and quickly determine their storage information, each wafer bin is equipped with a fixed RFID tag pre-written with its information. This information includes a wafer bin ID and wafer bin parameters. The parameters include the total number of layers in the wafer bin, the effective number of wafer layers within the bin, and product attribute information. The product attribute information includes the total number of chips on all wafers in the bin, a list of Bin values ​​for all chips on all wafers in the bin, and production batch information.

[0046] Similarly, the sorting scenario also includes multiple unloading bins. These unloading bins are similar in appearance and easily confused. To facilitate the differentiation of different unloading bins and quickly determine their storage information, each unloading bin is equipped with a fixed unloading bin RFID tag containing unloading bin information, including the unloading bin ID and unloading bin attribute parameters. The unloading bin attribute parameters include the total number of layers in the unloading bin, the effective number of layers of material sheets arranged in the unloading bin, and production batch information.

[0047] After placing the wafer hopper onto the wafer hopper placement platform of the sorting machine, the RFID reader on the platform reads the wafer hopper information from the RFID tags. This allows for the sequential loading and sorting of wafers within the hopper according to the wafer hopper information, and real-time display of sorting status statistics based on wafer hopper parameters. Similarly, the RFID reader on the unloading hopper placement platform reads the unloading hopper information from the RFID tags, providing real-time sorting status statistics based on unloading hopper parameters. Furthermore, since both the wafer hopper and unloading hopper information carry valid documentation, there is no need to scan the wafer hopper and unloading hopper before operation to determine if there are still wafers / wafers in the corresponding layers.

[0048] Furthermore, the sorting machine can communicate with the AGV scheduling system through a standardized interface to achieve unmanned material handling and automatic docking with the machine. In actual sorting, it is often necessary to move the corresponding wafer silos from the racks to the sorting machine's wafer silo placement platform. This step can be automated using AGVs. Specifically: based on the received sorting instructions, the target wafer silo ID and its storage location are determined. The AGV is then controlled to move to the target wafer silo storage location, and its RFID reader reads the wafer silo ID from the RFID tag of the wafer silo at the target storage location. When the wafer silo ID in the RFID tag of the wafer silo at the target storage location matches the target wafer silo ID, the AGV is controlled to move the wafer silo from the target storage location to the sorting machine's wafer silo placement platform; otherwise, an error is reported.

[0049] After sorting, the ID of the unloading bin to be transferred is determined based on the received transfer instruction. Then, the AGV is controlled to move to the target wafer storage location, and the RFID reader on the AGV reads the unloading bin ID from the RFID tag of the unloading bin at the target wafer storage platform. The AGV then automatically transfers the unloading bin with the same ID to the designated temporary storage area or the next process step without manual intervention, reducing the risk of human error and improving production line efficiency.

[0050] In this application, since the wafer hopper and unloading hopper are mostly made of metal, they can cause shielding interference to RFID signals. Furthermore, cleanrooms have extremely high requirements for equipment cleanliness and electrostatic discharge (ESD) protection. Therefore, the packaging and installation of RFID tags are specifically designed for the working environment of semiconductor cleanrooms. RFID tags on various core components are all ultra-high frequency passive RFID tags with ceramic substrates or flexible FPC anti-metal properties. The RFID tags are adhered to non-conductive areas of the core components to avoid direct contact with metal that could cause signal attenuation. Cleanroom-specific 3M adhesive is used for adhesion, offering advantages such as UV resistance and no adhesive residue. Passive RFID tags require no power supply, are small in size, and have no circuit components, making them superior to active RFID tags in terms of security and environmental adaptability. The surface roughness of each RFID tag does not exceed 0.1μm, meeting the cleanliness requirements of Class 100 cleanrooms. The encapsulation rating reaches IP67, allowing it to withstand routine cleanroom wiping and cleaning, while also possessing ±10KV ESD protection to prevent ESD damage to the wafer or tag chip.

[0051] In addition, to prevent error-proofing failure due to human tampering with tag information or tag replacement, data security design is added, including hardware and software security measures: At the hardware level, tamper-proof passive RFID tags are selected, with a built-in breakpoint antenna between each RFID tag and its adhesive surface. The breakpoint antenna breaks the circuit and disables the RFID tag when it separates from the adhesive surface. At the software level, the RFID tags only support encrypted reading and writing by RFID readers with modification permissions, and an information protection lock is set. Only authorized workstations can unlock and modify the tags using encrypted commands. Furthermore, encrypted data transmission between the RFID reader and the RFID tag, such as using AES-128 encryption, is used to prevent information leakage or tampering caused by signal interception.

[0052] To ensure system compatibility, the RFID tags and RFID readers used support RS485, TCP / IP, etc. The final system reserved interface is designed to support MES and Secs / Gem(II) to meet the requirements of full-process traceability and data interoperability in semiconductor production.

[0053] When an RFID reader at any workstation fails to read or write an RFID tag, it automatically triggers a power fine-tuning (±3dBm) and performs multiple retries to reduce the impact of signal interference. When the number of failed RFID tag reads reaches a set threshold, a manual authorization emergency channel is set up. The relevant tag information is read using a barcode scanner, and after administrator confirmation, it is manually entered into the system for verification. Simultaneously, an emergency operation log is recorded. Additionally... The system also automatically associates the working status and signal strength data of RFID readers at each workstation. When inconsistencies or anomalies occur, the abnormal workstation is marked on the human-machine interface in real time, and troubleshooting guidance is pushed, such as checking whether the RFID tag has shifted or the RFID reader has deviated, thus improving the efficiency of fault handling.

[0054] In another embodiment, an edge computing middleware can be added between the sorting machine control system and the MES system. This middleware performs data preprocessing functions, including deduplication, filtering, and format standardization conversion (supporting JSON / XML / CSV formats) of the raw data collected by RFID readers at each workstation, eliminating invalid data and improving system response speed. The edge computing middleware automatically identifies and interfaces with the MES system and matches the corresponding data interaction protocol through built-in adapter plugins for different MES systems, eliminating the need for manual configuration. It then receives instruction data from the MES system and uploads relevant data to it. When the MES system network is interrupted, the edge computing middleware automatically caches sorting records and real-time sorting status statistics, automatically re-uploading them after the network is restored to ensure no data loss. The edge computing middleware also automatically generates a full-process traceability report for the material tray based on the cached data (including read / write time, verification results, and anomaly records for each workstation), supporting direct access to the MES system or local export, meeting semiconductor manufacturing compliance requirements.

[0055] The above descriptions are merely preferred embodiments of this application, and this application is not limited to the above embodiments. It is understood that other improvements and variations that can be directly derived or conceived by those skilled in the art without departing from the spirit and concept of this application should be considered to be included within the protection scope of this application.

Claims

1. A wafer sorting and management method based on RFID tags, characterized in that, The wafer sorting and management method includes: The sorting record is queried according to the received sorting instruction, which indicates the target Bin value to be sorted; the sorting record records the sorting entries for each piece in the unloading bin, and each piece sorting entry records the piece information and chip loading information of the current piece. The piece information includes the piece ID, the piece storage location in the unloading bin, and the corresponding Bin value; each piece in the unloading bin has a piece RFID tag fixed to its non-conductive area and the piece information is pre-written thereon. Based on the material sorting entries of each material in the sorting record, select the material corresponding to the target Bin value in the sorting instruction as the target material, and read the target material ID and target material storage location from the sorting record; The RFID reader at the material loading station of the sorting machine is used to read the material information in the RFID tag of the material at the storage location of the target material; When the chip ID in the chip information of the chip at the target chip storage location matches the target chip ID, the target chip at the target chip storage location in the lower hopper is extracted and pushed to the sorting machine's worktable. Chips with the target Bin value in the current wafer are sorted into the target chips, and the sorting record is dynamically updated during the sorting process.

2. The wafer sorting and management method according to claim 1, characterized in that, The chip loading information for each chip includes real-time loading status and loading attribute parameters. The real-time loading status is either empty, partially loaded, or fully loaded. The real-time loading status of each chip is initialized to empty. Based on the material sorting entries in the sorting record, select a material piece corresponding to the target Bin value as the target material piece, and dynamically update the sorting record during the sorting process, including: When a wafer with the target Bin value and in a partially loaded state exists in the sorting record, the wafer with the target Bin value and in a partially loaded state is taken as the target wafer; otherwise, one of the wafers with the target Bin value and in an unloaded state is taken as the target wafer. The loading attribute parameters of the target wafer are read from the sorting record, and the chips with the target Bin value in the current wafer are sorted into the target wafers according to the loading attribute parameters of the target wafers, and the chip loading information of the target wafers is dynamically updated.

3. The wafer sorting and management method according to claim 2, characterized in that, The loading attribute parameters for each wafer include the number of chips already loaded, the maximum number of chips loaded, the chip loading row and column specifications, and the row and column coordinates of the last chip on the wafer. Based on the loading attribute parameters of the target wafer, chips with the target Bin value in the current wafer are sorted into the target wafer, and the chip loading information of the target wafer is dynamically updated, including: Based on the chip loading row and column specifications and the row and column coordinates of the last chip on the target wafer, the chips with the target Bin value in the current wafer are loaded onto the target wafer in sequence, and arranged in rows and columns starting from the next row and column coordinate of the last chip on the target wafer. When the number of chips loaded in the target wafer reaches the maximum loading quantity, the target wafer is placed back in the target wafer storage location, the real-time loading status of the target wafer in the sorting record is updated to full load status, and the loading attribute parameters of the target wafer in the sorting record are updated; if there are still unsorted chips with target Bin values ​​in the current wafer, the step of selecting one of the wafers with the target Bin value and in an unloaded state as the target wafer is re-executed. When all chips with the target Bin value in the current wafer are loaded into the target wafer, and the number of chips loaded in the target wafer has not yet reached the maximum loading quantity, the target wafer is placed back into the target wafer storage location. The real-time loading status of the target wafer in the sorting record is kept in a partially loaded state or updated from an empty state to a partially loaded state, and the loading attribute parameters of the target wafer in the sorting record are updated.

4. The wafer sorting and management method according to claim 1, characterized in that, The wafer sorting and management method further includes: The RFID reader at the wafer loading station of the sorting machine reads the wafer information in the wafer RFID tag of the current wafer. Each wafer has a fixed wafer RFID tag in the non-conductive area and the wafer information is pre-written. The wafer information includes the wafer serial number and wafer attribute parameters. The wafer attribute parameters include the total number of chips, the list of Bin values ​​containing chips, the wafer warehouse ID of the wafer warehouse to which the wafer belongs, and the production batch information. The current wafer's mapping map is read based on its serial number. The chips on the current wafer are sorted according to the current wafer's mapping map, and the real-time sorting status statistics are displayed based on the wafer's attribute parameters.

5. The wafer sorting and management method according to claim 4, characterized in that, The wafer information for each wafer also includes wafer specifications, and the wafer sorting management method further includes: The size detection sensor at the wafer loading station of the sorting machine detects the actual specifications of the wafer at the target wafer storage location. When the wafer ID in the wafer information at the target wafer storage location matches the target wafer ID, and the actual specifications of the wafer at the target wafer storage location match the wafer specifications of the current wafer, the target wafer at the target wafer storage location is extracted from the unloading bin and pushed to the sorting machine's worktable; otherwise, loading is stopped and an alarm is triggered.

6. The wafer sorting and management method according to claim 1, characterized in that, The wafer sorting and management method further includes: Based on the received sorting instructions, the target wafer warehouse ID and its storage location are determined. The AGV is controlled to move to the target wafer warehouse storage location, and the RFID reader on the AGV reads the wafer warehouse ID from the wafer warehouse RFID tag at the target wafer warehouse storage location. Each wafer warehouse has a fixed wafer warehouse RFID tag with pre-written wafer warehouse information. The wafer warehouse information for each wafer warehouse includes the wafer warehouse ID and wafer warehouse parameters. The wafer warehouse parameters include the total number of wafer warehouse layers, the effective number of wafer layers arranged in the wafer warehouse, and product attribute information. The product attribute information includes the total number of chips in the wafer warehouse, the Bin value list, and the production batch information. When the wafer warehouse ID in the wafer warehouse RFID tag at the target wafer warehouse storage location matches the target wafer warehouse ID, the AGV is controlled to transport the wafer warehouse at the target wafer warehouse storage location to the wafer warehouse placement platform of the sorting machine. The RFID reader at the wafer warehouse placement platform of the sorting machine reads the wafer warehouse information from the wafer warehouse RFID tag. According to the wafer warehouse information, each wafer in the wafer warehouse is loaded and sorted in sequence. Real-time sorting status statistics are obtained based on the wafer warehouse parameters and displayed in real time.

7. The wafer sorting and management method according to claim 1, characterized in that, The target wafer storage location includes the target unloading bin ID and the target layer number of the target wafer within the unloading bin. Several unloading bins are placed on the unloading bin placement platform of the sorting machine. The wafer sorting management method further includes: The RFID reader at the material loading station of the sorting machine is used to read the material loading RFID tag information of each material loading bin. The material loading information of each material loading bin includes the material loading bin ID and material loading bin attribute parameters. The material loading bin attribute parameters include the total number of layers in the material loading bin, the effective number of material loading layers in the material loading bin, and the production batch information. If the effective number of material layers arranged in the feeding bin with the same ID as the target feeding bin includes the target number of layers, then the material layer with the target number of layers in the feeding bin with the target feeding bin ID is determined as the target material; otherwise, an alarm is triggered.

8. The wafer sorting and management method according to claim 1, characterized in that, The wafer sorting and management method further includes: RFID tags are affixed to the wafer tray frame; The chip loaded on the sheet is ejected at the sorting machine's discharge station. The RFID reader at the sorting machine's discharge station erases the sheet information from the RFID tag, discards the blue film of the sheet, and recycles the tray frame. The recycled material tray frame is fitted with a new blue film to obtain brand new material pieces. The RFID reader at the sorting machine's warehousing station is used to write the new material piece information into the material piece's RFID tag. After writing, the material piece is placed in the corresponding material piece storage location in the unloading hopper, and a new material piece sorting entry for the current material piece is added to the sorting record. The material piece information is written into the corresponding material piece sorting entry, and the chip loading information is initialized.

9. The wafer sorting and management method according to claim 1, characterized in that, Each RFID tag has a built-in breakpoint antenna between it and its adhesive surface. The breakpoint antenna breaks the circuit and disables the RFID tag when it is separated from the adhesive surface. The RFID tag can only be read and written encrypted by RFID readers with modification permissions.

10. The wafer sorting and management method according to claim 1, characterized in that, Each RFID tag is an ultra-high frequency passive RFID tag made of ceramic substrate or flexible FPC anti-metal, and has ±10KV anti-static capability.

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