Automatic wafer transfer method

Abstract

The invention discloses an intelligent nitrogen storage method for semiconductor wafers. The intelligent nitrogen storage method is applied to a system comprising transition purification equipment, a rotary table assembly, a sealing door assembly, a wafer manipulator, a roadway stacker and a gas circulation device. The method comprises the following steps: step 1, feeding and pre-purifying; 2, caching and carrying ring arrangement are conducted, specifically, a carrying ring carrier is cached to a goods shelf through a material taking mechanical arm; 3, rotary connection and posture adjustment are conducted, an air brake is achieved in cooperation with a sealing door, the carrier ring carrier rotates by about 180 degrees through a rotary table to face a roadway, and meanwhile an outer side door and an inner side door are alternately opened and closed to form the air brake; 4, transferring and storing in a roadway, wherein the wafer mechanical arm receives the ring carrying carrier and transfers the ring carrying carrier to a roadway stacking machine to be warehoused; and 5, nitrogen circulation and environment maintenance. Through cooperative control of feeding pre-purification, rotary connection, a double-door air brake and nitrogen circulation, non-contact, high-cleanliness and high-density automatic nitrogen storage of wafers is achieved, and pollution and nitrogen leakage are effectively prevented.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and more specifically to an automated wafer transfer method based on a rotary table and a robotic arm. Background Technology

[0002] Automated wafer transfer technology, belonging to the semiconductor manufacturing field, involves the efficient and safe transfer of wafers during wafer production and storage, and is a key link in ensuring product quality and production efficiency. With the rapid development of integrated circuit technology, wafer sizes are constantly increasing while process linewidths are continuously shrinking. The requirements for environmental cleanliness, oxygen content, humidity, and alignment accuracy in the manufacturing process are becoming increasingly stringent. Wafer transfer equipment needs to operate fully automatically under conditions of pollution prevention, oxidation prevention, and high-density storage. To this end, the industry has gradually introduced technologies such as robotic arms, rotary tables, and sealed isolation devices to optimize transfer paths and environmental control, reducing damage and contamination of wafers during transfer. However, how to simultaneously achieve efficient transfer, cleanliness assurance, and high-density storage in complex production environments remains a significant technological challenge.

[0003] Several systems and methods for automated wafer handling have been disclosed in the prior art. For example, Chinese Patent Publication No. CN118486623A provides an automated high-altitude wafer handling system and method. This system utilizes a lifting mechanism, a moving mechanism, a clamping mechanism, and a connecting conveyor line on a semiconductor main equipment, and sets up a first and second conveyor line on top of the equipment to achieve automated handling and unloading of wafer cassettes at high altitudes. The handling method uses the lifting mechanism in conjunction with the upper and lower conveyor lines to transport and change the height of the wafer cassettes at high altitudes. The lifting belt is wound and released by pulleys to lower the high-positioned wafer cassettes to the operating height, thus achieving relatively flexible high-altitude wafer cassette handling within the factory and reducing the cost and maintenance of traditional OHT (overhead crane) systems. However, this technical solution mainly addresses the problem of handling wafer cassettes between different workstations or equipment and does not provide an overall design for large-capacity storage scenarios under nitrogen protection.

[0004] In other existing transfer systems, wafer transfer typically relies on a combination of robotic arms and conveyor devices to move wafers from external to internal processes or storage areas. For example, conveyor belts or robotic arms transport wafers from external buffer areas to the production line or local storage units. However, these solutions often operate in open or semi-open environments, making it difficult to completely avoid direct contact between wafers and external air. Wafers are susceptible to particle or moisture contamination during transfer, leading to surface defects or oxidation. Wafers are often transferred as bare wafers or simply placed on pallets, lacking dedicated ring-shaped carriers for directional clamping. This can cause wobbling, misalignment, or even collisions during high-speed handling or complex path transitions, resulting in potential physical damage. Existing rotary tables or steering mechanisms generally only support simple linear motion or fixed angle transitions, lacking precise directional clamping mechanisms and fine angle control in conjunction with dedicated carrier rings. This makes it difficult to achieve high-precision attitude adjustment and shelf alignment of wafers when entering internal storage. When dealing with high-density storage needs, existing solutions do not make full use of the aisle cross-section and rack layout. The transfer path design and airflow organization are often carried out separately, which can easily form dust accumulation areas in the aisles and affect the cleanliness of wafers during long-term storage.

[0005] To improve storage conditions in a nitrogen environment, nitrogen cabinet solutions have emerged in the prior art. For example, Chinese Patent Publication No. CN221977879U discloses a wafer cassette storage device. Inside the nitrogen cabinet, there are shelves for storing wafer cassettes, nitrogen pipelines for replenishing nitrogen, and a stacker crane for transferring wafer cassettes between the shelves. A transfer cabinet is set on one side of the nitrogen cabinet, and a first sealing door and a second sealing door are respectively set in the passage between the nitrogen cabinet and the transfer cabinet. The wafer cassettes are picked up by servo grippers on the stacker crane, and with the help of the double sealing door structure, the automatic storage and retrieval of wafer cassettes between the nitrogen cabinet and the outside world and a certain degree of isolation between the internal and external environments are achieved. This solution enables automated storage and transfer of wafer cassettes in a nitrogen environment. However, it uses wafer cassettes as the basic carrier and focuses primarily on storage and retrieval within the nitrogen cabinet and between transfer cabinets. It does not address the pre-purification and buffering process of the wafer carrier ring between the transition purification equipment and the loading buffer rack. Furthermore, it does not disclose the setting of a rotating docking station facing the carrier ring at the aisle entrance to clamp, position, and rotate the carrier ring approximately 180° to complete the conversion between the external direction and the aisle direction. Moreover, it does not combine this rotating docking station with the alternating opening and closing of the outer and inner doors to form a methodological double-door airlock control.

[0006] In summary, existing technologies for automated wafer transfer and nitrogen storage still suffer from the following shortcomings: They lack an integrated process flow encompassing pre-purification of incoming materials, buffering and organizing of carrier rings, rotary docking and attitude adjustment, and contactless transfer within aisles to multi-row rack storage. The linkage control between the rotary docking station and the double-door airlock is insufficient, resulting in limited effectiveness in controlling nitrogen leakage and preventing external contamination. The high-density storage and airflow circulation design within aisles lack unified consideration, making it difficult to balance long-term storage cleanliness with system operational efficiency. A systematic switching method has not yet been established between nitrogen protection mode and oxygen supply mode required for personnel maintenance. Therefore, it is necessary to provide a new intelligent nitrogen storage method for semiconductor wafers based on a rotary table and robotic arms. This method, while achieving contactless automated wafer transfer, addresses the high contamination risk, insufficient directional adjustment accuracy, and inadequate airflow circulation optimization issues of existing technologies through a comprehensive design that integrates carrier ring directional clamping, aisle structure and multi-row rack coordination, and nitrogen circulation and oxygen supply control. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides an automated wafer transfer method. Its purpose is to achieve contactless transfer of wafers from external cache to internal storage. Through the coordinated operation of a rotary table and a robotic arm, combined with directional clamping and sealing isolation, wafer contamination and damage are prevented, airflow circulation in the aisle is optimized, dust accumulation is reduced, and the high-density storage requirements under a nitrogen environment are met.

[0008] A method for intelligent nitrogen storage of semiconductor wafers is applied to a storage system including a transition purification device, a material handling robot, a loading buffer rack, a carrier ring rotary table and rotary table assembly, a sealing door assembly, a wafer robot, an aisle stacker crane, multi-row racks, a gas circulation device, and an oxygen supply module. The method includes the following steps: Step 1, Feeding and Pre-purification Step: The wafer cassette loaded with wafers is fed into the transition purification equipment through the feeding device. The air in the feeding area is filtered and purified by the airflow purification unit inside the transition purification equipment. Step 2, Cache and Carrier Ring Arrangement: The material handling robot removes the carrier rings that carry the wafers one by one from the wafer box and places the carrier rings in the designated location of the loading cache shelf for caching. The loading cache shelf is used to store multiple carrier rings in an orderly manner. Step 3, Rotary Connection and Attitude Adjustment and Airlock Implementation with Sealing Door: Under the control of the control system, the buffer ring carrier is transferred from the loading buffer shelf to the rotary table on the rotary table assembly at the aisle entrance. The rotary table assembly clamps and positions the ring carrier and drives the rotary table to rotate around the central axis, turning the ring carrier from facing outward to facing inward into the aisle. At the same time, the outer and inner doors of the sealing door assembly are controlled to open and close alternately, so that the aisle entrance is always in an airlock state when the ring carrier enters and exits the aisle. Step 4, Transfer and Storage within the Aisle: When the inner door of the sealed door assembly is opened, the wafer robot, guided by the sealed guide mechanism, picks up the carrier ring from the rotary table assembly, clamps the carrier ring without contacting the wafer surface, and transfers it along the aisle direction to the platform position of the aisle stacker; subsequently, the aisle stacker receives the carrier ring and moves along the aisle and rack direction, transporting the carrier ring to the designated storage location of the multi-row racks to complete the warehousing; Step 5, Nitrogen Circulation and Environmental Maintenance: Nitrogen is supplied and circulated into the warehouse through a gas circulation device. The temperature-controlled and purified nitrogen flows through multiple rows of shelving areas in a directional airflow manner, and the return air is sent back to the gas circulation device for temperature, humidity and particle filtration.

[0009] Furthermore, in step one, the transition purification equipment is equipped with a filter unit and a guide air duct. The filter unit uses high-efficiency filter material to filter particles in the air entering the feeding area. The guide air duct is used to form a directional airflow from top to bottom and / or from back to front, so that the wafer cassette is always in a purified directional airflow environment before it is sent into the loading buffer shelf by the feeding device.

[0010] Furthermore, in step two, the loading buffer rack is a multi-layer structure arranged vertically, with each layer having a positioning position for limiting the carrier ring of the wafer; the material handling robot has a multi-degree-of-freedom gripping mechanism, configured to remove the carrier ring of the wafer from the wafer box one by one without contacting the wafer surface, and place the carrier ring in the positioning position of each layer for buffering in a predetermined order.

[0011] Furthermore, in step three, the buffer carrier ring is transferred from the loading buffer shelf to the hollow turntable on the rotary table assembly at the aisle entrance. The clamping assembly holds the outer edge of the carrier ring and / or the recessed positioning structure, and the sensor assembly detects the positioning status of the carrier ring. After detecting that the carrier ring is in place and the clamping is stable, the motor pulley assembly drives the hollow turntable to rotate around its central axis, causing the carrier ring to rotate approximately 180° relative to the aisle direction, from facing outwards to facing the wafer robot inside the aisle, thereby completing the adjustment of the carrier ring's posture and docking with the transfer direction within the aisle.

[0012] Furthermore, the clamping assembly includes at least two sets of clamping arms arranged opposite to each other, a guide post and a linear bearing slidably connected to the clamping arms, and a cylinder assembly connected to the clamping arms. The clamping arms open and close along a predetermined linear direction under the guidance of the guide post and the linear bearing, and apply a clamping force to the carrier ring under the action of the spring mechanism, thereby maintaining the directional stability of the carrier ring and improving the repeatability of the clamping and releasing actions during the approximately 180° rotation of the hollow turntable.

[0013] Furthermore, in step four, the sealing door assembly includes an outer door and an inner door located on the outside and inside of the tunnel entrance, a sealing panel located on the inner surface of the door body, and a sealing component arranged between the sealing panel and the edge of the tunnel entrance. When the carrier ring enters from the outside, the outer door is controlled to open and the inner door to close. After the carrier ring completes approximately 180° rotation and connection via the rotary table assembly, the outer door is closed, and then the inner door is opened as needed. When the door is closed, the sealing panel fits against the sealing component to form an airlock structure at the tunnel entrance when the outer door and the inner door are closed respectively, so that the carrier ring is always isolated from the external environment while the outer door and the inner door are alternately open during the process of entering and exiting the tunnel entrance.

[0014] Furthermore, the sealing door assembly also includes a motor pulley assembly for driving the reciprocating motion of the sealing panel and a limiting assembly for limiting the travel of the sealing panel. The motor pulley assembly includes a servo motor fixed on the frame and a synchronous belt connected to the sealing panel. The servo motor drives the sealing panel to slide open and close along the guide structure via the synchronous belt. The limiting assembly is located at the end of the guide structure and is used to limit the maximum open position and the minimum closed position of the sealing panel.

[0015] Furthermore, in step four, the wafer robot is mounted on a sealing screw module. The sealing screw module includes a linear guide rail arranged along the aisle direction, a ball screw that cooperates with the linear guide rail, and a linear displacement measurement sensor set at the bottom of the sealing screw module. The ball screw is used to guide the wafer robot to move laterally along the aisle direction, and the linear displacement measurement sensor is used to detect the displacement position of the wafer robot in the aisle direction in real time and feed the detection result back to the control system. This allows the wafer robot to accurately transfer the carrier ring from the rotary table assembly to the platform position of the aisle stacker while supporting the bottom and gripping the outer contour of the carrier ring.

[0016] Furthermore, in step four, the aisle stacker crane includes a platform assembly slidably mounted on the stacker crane track. The top of the platform assembly is provided with a clamping part, which has an arc-shaped clamping surface that matches the outer edge shape of the carrier ring. When the aisle stacker crane receives the carrier ring transferred from the wafer robot, during the acceleration, deceleration, and lifting / lowering process in the aisle direction and the shelf direction, the carrier ring is wrapped and clamped by the arc-shaped clamping surface, and the carrier ring is transported to the designated storage slot position of the multi-row shelf and the warehousing is completed.

[0017] Furthermore, in step five, the gas circulation device includes a temperature-regulating and purification component, a static pressure box, an air supply duct, and a return air duct. The temperature-regulating and purification component adjusts the temperature, humidity, and particulate matter concentration of the circulating gas. After being pressurized by the static pressure box, high-purity nitrogen is introduced into the multi-row shelf area through the air supply duct to form a directional airflow from top to bottom and / or from back to front. The return air duct draws gas from the bottom of the shelves and / or the lower part of the aisle and sends it back to the temperature-regulating and purification component, thereby forming a closed-loop circulating gas path. The oxygen supply module is connected to the internal space of the warehouse through pipelines and is used to replace the nitrogen circulation to supply oxygen or clean air to the inside of the warehouse when personnel maintenance or other abnormal operating conditions are required.

[0018] The automated wafer transfer method proposed in this invention has the following advantages: by sequentially integrating pre-purification of incoming materials, buffer organization, rotary docking and airlock control, contactless transfer within the aisle, and maintenance of a nitrogen environment into a continuous process flow, the wafers are kept in a controlled clean environment throughout the entire warehousing path. By setting up a transitional purification process before the wafers enter the internal storage, the wafer cassette is enveloped by a directional clean airflow before entering the buffer stage, thereby reducing the pollution load of external air on the subsequent environment and improving the system's front-end cleanliness assurance capability.

[0019] During the caching and sorting phase, a robotic arm is used to remove the wafer carrier rings from the wafer cassette one by one and place them sequentially in a multi-layered buffer rack. This ensures a continuous and stable feeding rhythm for discrete wafers arriving from external batches, providing a reliable intermediate buffer for the transfer station. This method avoids the batch imbalance problem caused by direct handling of wafer cassettes in traditional methods.

[0020] When the carrier ring enters the connection stage, the method adjusts the carrier ring from an outward-facing state to an inward-facing state by first clamping and positioning it, and then rotating it for orientation adjustment. The rotation is reliably completed with the help of clamping, preventing the carrier ring from shifting during the rotation process. At the same time, the method uses interlocking and alternating control of the outer and inner doors, ensuring that there is always a closed, sealed door when the carrier ring enters or exits the roadway entrance. This creates a double-door airlock effect, effectively suppressing nitrogen leakage and preventing external contaminants from entering.

[0021] After the carrier ring completes its orientation adjustment and passes through the inner door, it is transferred non-contactly within the aisle by a wafer robot. This method, through a combination of bottom support and lateral clamping, ensures that the force is always applied to the carrier ring rather than the wafer itself, significantly reducing the risk of wafer scratches or wafer slippage. Using linear guides, ball screws, and position detection, the wafer robot can precisely hand over the carrier ring to the aisle stacker, avoiding alignment errors and the risk of contamination from repeated gripping.

[0022] After receiving the carrier ring, the stacker crane smoothly delivers it to the corresponding storage slot on the rack using a wrapping gripping surface. Because the method employs directional force and regionalized stroke planning from receiving to warehousing, the carrier ring maintains stability even in high-density storage environments. This makes it suitable for multi-row, multi-layer inventory structures, improving warehouse space utilization and warehousing efficiency.

[0023] Throughout the entire transfer process, the nitrogen circulation system within the warehouse remains continuously operational. Through closed-loop control of temperature regulation, pressure equalization, air supply, and return, inert nitrogen is directed to cover the aisles and shelving areas in a directional airflow pattern, ensuring that each wafer is in a low-oxygen, low-particle environment during storage and transfer. This method combines continuous environmental control with real-time transfer operations, not only improving the stability of the internal environment but also reducing the risk of particle resuspension caused by localized turbulence.

[0024] Furthermore, this method also exhibits good scalability in anomaly handling and maintenance scenarios. When manual entry into the storage area is required, the method allows for reducing the nitrogen supply and switching to oxygen supply mode to ensure the internal environment meets the safety requirements for personnel operations. After maintenance, the nitrogen environment and automated processes are restored sequentially, achieving a smooth transition from maintenance to transfer.

[0025] Overall, the method of this invention achieves contactless transfer, orientation stability, clean isolation, and high-precision alignment of wafers throughout the entire warehousing process by sequentially integrating and conditionally interlocking the various links in the transfer link. This significantly reduces the risk of contamination and improves system operating efficiency, making it particularly suitable for high-cleanliness, high-stability, and high-density nitrogen storage scenarios required by advanced processes. Attached Figure Description

[0026] Appendix Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0027] Appendix Figure 2 This is a top view of the structure of the present invention.

[0028] Appendix Figure 3 This is a schematic diagram of the sealing door assembly structure of the present invention.

[0029] Appendix Figure 4This is a top view of the rotating platform and sealing door structure of the present invention.

[0030] Appendix Figure 5 This is a schematic diagram of the wafer manipulator and linear module structure of the present invention.

[0031] Appendix Figure 6 This is a three-dimensional structural diagram of the rotating docking platform of the present invention.

[0032] Appendix Figure 7 This is a top view of the rotating docking platform of the present invention.

[0033] Appendix Figure 8 This is a schematic diagram of the internal structure of the sealing door assembly of the present invention.

[0034] Appendix Figure 9 This is a schematic diagram of the carrier clamping part of the carrier ring of the present invention.

[0035] Appendix Figure 10 This is a flowchart of the automated wafer transfer method of the present invention.

[0036] Figure labels: 1-Transitional purification equipment; 2-Material handling robot; 3-Feeding buffer rack; 4-Carrier ring rotary table; 5-Aisle stacker crane; 6-Sealing door assembly; 7-Frame assembly; 8-Sealing assembly; 9-Electrical distribution panel assembly; 10-Rotary table assembly; 11-Wafer robot; 12-Drag chain assembly; 13-Sealing screw module; 14-Base assembly; 15-Rotary table support plate; 16-Sensor assembly; 17-Hollow rotary table; 18-Platform assembly; 19-Clamping assembly; 20-Cylinder assembly; 21-Fixing plate; 22-Sealing panel; 23-Motor pulley assembly; 24-Limiting assembly; 25-Guide column and bracket assembly; 26-Linear guide rail; 27-Ball screw; 28-Clamping part. Detailed Implementation

[0037] The technical solution of the present invention will now be clearly and completely described in conjunction with the accompanying drawings. In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The invention will be further described below with reference to the accompanying drawings.

[0039] This invention provides an automated wafer transfer system: such as Figure 1 and Figure 2 As shown, a transitional purification device 1 is installed in the area outside the entrance of the alley, and a feeding buffer shelf 3 is installed on the adjacent side. A material handling robot 2 is arranged between and above the two. The transitional purification device 1 is preferably a box structure, and an airflow purification device or filter unit and a guide air duct are installed in the top and / or rear of the device to form a directional clean airflow environment inside the device.

[0040] The loading buffer rack 3 adopts a multi-layer storage compartment structure, with several layers arranged vertically. Each layer has multiple storage positions with positioning slots or limiting blocks to define the placement posture of the wafer carrier rings or wafer boxes. The picking robot 2 is fixed to the equipment frame by a mounting base and has a multi-degree-of-freedom robotic arm and an end-effector gripping mechanism. Its workspace covers the discharge position of the transition purification equipment 1 and the storage positions of each layer of the loading buffer rack 3, so as to transfer the wafer carrier rings between the two.

[0041] like Figure 4 , Figure 6 and Figure 7 As shown, a ring-carrying rotary table 4 is arranged at the entrance of the tunnel. The ring-carrying rotary table 4 is fixed to the ground or a base via a base assembly 14. A rotatable hollow rotary table 17 is mounted on the base assembly 14. The hollow rotary table 17 rotates around its own axis supported by bearings, and its top surface is fixedly connected to a rotary table support plate 15. A clamping assembly 19 and a sensor assembly 16 are mounted on the rotary table support plate 15. The clamping assembly 19 includes several opposing clamping arms, guide columns, a support assembly 25, and linear bearings. The clamping arms reciprocate linearly along the direction of the guide columns under the drive of the cylinder assembly 20 to form a clamping space for clamping the outer edge of the ring carrier or the recessed positioning structure. The sensor assembly 16 is located at the side edge of the rotary table support plate 15 and is used to detect whether the ring carrier is in place or whether the clamping is complete. A motor pulley assembly 23 is installed on the lower or side of the hollow turntable 17. The servo motor in the motor pulley assembly 23 is connected to the hollow turntable 17 through a driving pulley, a driven pulley and a synchronous belt, and is used to drive the hollow turntable 17 to rotate about 180°.

[0042] like Figure 3 and Figure 8 As shown, a sealing door assembly 6 is installed around the entrance of the tunnel. The sealing door assembly 6 includes a frame assembly 7, a sealing panel 22, a sealing component 8, a motor pulley assembly 23, a limiting component 24, a fixing plate 21, and a guide post and bracket assembly 25. The frame assembly 7 is installed on both sides of the tunnel entrance, forming a door frame support structure. The sealing panel 22 is slidably connected to the frame assembly 7 via the guide post and bracket assembly 25, allowing the tunnel entrance to be opened or closed in a predetermined direction. The sealing component 8 is installed between the sealing panel 22 and the edge of the tunnel entrance, preferably a surrounding elastic sealing strip, used to press against the sealing panel 22 to form an annular seal when closed. The motor pulley assembly 23 is fixed to the frame assembly 7, with one end of a synchronous belt connected to the sealing panel 22 and the other end wound around a pulley on the output shaft of a servo motor, used to drive the sealing panel 22 to reciprocate. The limiting component 24 is arranged at both ends of the guide path, used to limit the maximum open position and minimum closed position of the sealing panel 22. The fixing plate 21 is positioned at a suitable location on the frame assembly 7, providing an installation reference for electrical units such as the electrical distribution panel assembly 9. Depending on the needs, an outer door and an inner door can be constructed from the above-described structure on the outer and inner sides of the tunnel entrance, respectively.

[0043] like Figure 5 As shown, a sealing screw module 13 is arranged along the tunnel direction inside the tunnel. The sealing screw module 13 is fixed on the base assembly 14, and a linear guide rail 26 and a ball screw 27 are provided inside or outside the module. The linear guide rail 26 provides linear guidance for the wafer robot 11. The ball screw 27 is driven to rotate by a drive motor, and the nut seat or slider that engages with it is fixed to the wafer robot 11, thereby realizing the precise linear movement of the wafer robot 11 along the tunnel direction. A sealing cover can be provided on the outside of the sealing screw module 13, and a linear displacement measuring sensor can be installed at the bottom inside to detect the position of the wafer robot 11. The wafer robot 11 is fixed on the nut seat or guide rail slider of the ball screw 27, and its end effector includes a bottom support and a lateral clamping part for supporting and clamping the carrier ring inside the tunnel. The cable chain assembly 12 is located between the wafer robot 11 and the sealing screw module 13. It is used to house the cables and air pipes that provide power, electrical signals and air supply to the robot, and to provide flexible guidance when the robot moves.

[0044] like Figure 2 and Figure 4As shown, a stacker crane 5 is arranged in the middle area of ​​the aisle. The stacker crane 5 is installed on a crane track within the aisle, allowing it to slide along the aisle direction and move vertically up and down via an internal lifting mechanism to cover the storage locations of multiple rows and layers of shelving. A platform assembly 18 is installed at the front end of the stacker crane 5. The platform assembly 18 is connected to the main body of the stacker crane via a slide rail or linkage mechanism, and its top forms a clamping part 28. The clamping part 28 is preferably a clamping surface with a certain curvature, its arc contour matching the outer edge shape of the carrier ring, used to stably support and clamp the carrier ring during stacker crane operation.

[0045] Through the arrangement of the above structures, the transition purification equipment 1, the feeding buffer rack 3, the carrier ring rotary table 4 and rotary table assembly 10, the sealing door assembly 6, the wafer robot 11 and sealing screw module 13, the aisle stacker 5 and carrier assembly 18 are connected in space in sequence, providing a clear structural foundation for the subsequent steps in the automated wafer transfer method, such as feeding pre-purification, buffer sorting, rotary connection and airlock control, aisle transfer and stacker warehousing.

[0046] Example 1: Automated Transfer Method for Wafer Receiving

[0047] This embodiment corresponds to Figure 10 The flowchart shown is mainly used to illustrate the complete set of steps S101 to S105 of the process of wafers entering the nitrogen storage from the outside and completing the warehousing.

[0048] Step S101: Feeding and Pre-purification Step like Figure 1 As shown, an external production line or conveying device delivers a wafer cassette loaded with wafers to the inlet of the transition purification equipment 1, and the wafer cassette is pushed into the transition purification equipment 1 by a feeding device.

[0049] In this embodiment, the transition purification device 1 is internally equipped with a filter unit and a guide air duct, constituting an airflow purification unit. The filter unit uses high-efficiency filter material to filter particles from the air entering the feeding area; the guide air duct organizes the airflow into a directional airflow from top to bottom and / or from back to front.

[0050] This method, by executing step S101, ensures that the wafer cassette is always enveloped by a filtered and directed clean airflow before entering the feeding and buffering stage from the external environment. This introduces a "feeding pre-purification step" at the method level, reducing the particle load in the subsequent storage area and providing front-end cleanliness assurance for the entire nitrogen storage environment.

[0051] Step S102: Cache and Carrying Ring Compaction Steps After completing step S101, perform the cache and load ring reorganization steps.

[0052] like Figure 1 and Figure 2 As shown, the picking robot 2 is positioned between the transitional purification equipment 1 and the loading buffer shelf 3. In this method, the control system first positions the wafer cassette at the picking station, and then controls the end gripping mechanism of the picking robot 2 to remove the carrier ring (e.g., ring carrier) carrying the wafers one by one from the wafer cassette without contacting the wafer surface, and places each carrier ring into the designated location of the loading buffer shelf 3 in a predetermined order.

[0053] The loading buffer rack 3 adopts a multi-layer structure arranged vertically, with multiple positioning positions on each layer for limiting the carrier rings that hold the wafers. This method, through step S102, performs multi-layered orderly buffering and organization of the discretely arriving carrier rings: on the one hand, it decouples the wafers from the external process cycle, forming a buffer; on the other hand, it provides a continuous and stable supply source for subsequent rotating connections.

[0054] Step S103: Rotate the connector and adjust its attitude to cooperate with the sealing door to achieve the airlock step. This step is one of the core components of the method of this invention, completing the attitude adjustment of the carrier ring from "facing outward" to "facing inward", and cooperating with the double-door airlock.

[0055] like Figure 6 and Figure 7 As shown, when the control system detects that there is a carrier ring to be transferred in a certain position of the loading buffer shelf 3, it issues a command to drive the picking robot 2 to transfer the carrier ring from the loading buffer shelf 3 to the rotary table assembly 10 at the aisle entrance. The rotary table support plate 15 on the top of the hollow rotary table 17 provides the loading reference surface.

[0056] Then, perform the following steps: 1. Clamping in place detection The clamping assembly 19, driven by the cylinder assembly 20, closes synchronously along the straight line defined by the guide post and bracket assembly 25, clamping the outer edge of the carrier ring and / or the recessed positioning structure. The sensor assembly 16 detects whether the carrier ring is in position and whether the clamping is stable, and feeds back the detection signal to the control system.

[0057] 2. Rotary connector Once the carrier ring is detected to be in the correct position and securely clamped, the control system activates the motor pulley assembly 23, driving the hollow turntable 17 to rotate around the central axis. This causes the carrier ring to rotate approximately 180° relative to the tunnel direction, from facing outwards to facing the wafer manipulator 11 inside the tunnel. The directional clamping of the clamping assembly 19 maintains the carrier ring's stable posture throughout the rotation, preventing the wafer from wobbling or shifting.

[0058] 3. Sealing control When the carrier ring enters from the outside, the control system first opens the outer door of the sealing door assembly 6 while keeping the inner door closed. After the carrier ring completes the aforementioned clamping and approximately 180° rotation connection actions, the control system closes the outer door and then opens the inner door as needed, allowing the carrier ring to be picked up from the tunnel side by the wafer robot 11. Methodically, this ensures that the outer and inner doors are never simultaneously open, thus forming a double-door airlock structure at the tunnel entrance.

[0059] Through step S103, the present invention tightly couples "rotary docking" and "double-door airlock" in terms of method, which not only completes the orientation conversion of the carrier ring, but also realizes the suppression of nitrogen leakage and the isolation of external pollution during the process of entering and exiting the roadway. This is a key step that has not been systematically considered in existing methods.

[0060] Step S104: Transfer and storage within the tunnel When the inner door is opened and the material receiving conditions are met, the transfer and storage steps within the tunnel are executed.

[0061] like Figure 4 and Figure 5 As shown, the wafer robot 11 is mounted on the sealing screw module 13. The sealing screw module 13 includes a linear guide rail 26 and a ball screw 27 arranged along the tunnel direction, and a linear displacement measurement sensor is set at its bottom to detect the displacement position of the wafer robot 11 in the tunnel direction in real time.

[0062] This step specifically includes: 1. Take the carrier ring from the rotary table Based on the sensor feedback position, the control system moves the wafer robot 11 along the aisle direction to the docking position in front of the rotary table assembly 10. The end effector of the wafer robot 11 supports the carrier ring and clamps its outer contour, picking up the carrier ring from the clamping assembly 19 without contacting the wafer surface.

[0063] 2. Non-contact transfer along the tunnel direction Guided by the sealing screw module 13 and monitored in real time by the linear displacement measurement sensor, the wafer robot 11 moves the carrier ring laterally along the aisle direction to the platform assembly 18 of the aisle stacker 5. This contactless transfer, which uses the carrier ring as the direct force-bearing object, avoids direct contact with the wafer surface and significantly reduces the risk of physical damage and particle shedding.

[0064] 3. Hand over to the stacker crane in the roadway and complete the warehousing. When the wafer robot 11 delivers the carrier ring to the platform assembly 18 of the aisle stacker 5, the platform assembly 18 moves to the docking position and clamps the carrier ring using the top gripping part 28 (arc-shaped gripping surface). Subsequently, under the coordination of the control system, the wafer robot 11 releases the carrier ring and returns to a safe position. The aisle stacker 5 then carries the carrier ring along the aisle and shelf directions, accelerating, decelerating, and moving up and down to deliver the carrier ring to the designated storage slot on the multi-row shelf to complete the warehousing process.

[0065] Through step S104, the present invention establishes a wafer transfer link in the channel, forming an automated warehousing path suitable for high-density storage.

[0066] Step S105: Nitrogen Cycle and Environmental Maintenance Procedures During the execution of steps S101 to S104 and after the warehousing is completed, the gas circulation device continues to operate to maintain the nitrogen environment and high cleanliness inside the storage area. In this embodiment, the gas circulation device includes a temperature-regulating purification component, a static pressure box, an air supply duct, and a return air duct, etc. The temperature-regulating purification component comprehensively regulates the temperature, humidity, and particulate matter concentration of the circulating gas; The static pressure box, in conjunction with the air supply duct, evenly delivers the treated high-purity nitrogen into the multi-row rack area and aisle space, allowing it to flow through the carrier storage area in a directional airflow from top to bottom and / or from back to front. The return air duct draws return air from the bottom of the shelf and / or the lower part of the aisle and sends it back to the temperature and purification unit, thus forming a closed-loop circulating air path.

[0067] This method, through step S105, clarifies the "nitrogen circulation and environmental maintenance steps" at the step level, and integrates temperature and humidity control, particle filtration and airflow organization into the method flow, so that the nitrogen environment is deeply coupled with automated transfer, rather than simple static nitrogen filling.

[0068] Example 2: Outbound and Maintenance Mode

[0069] Based on Example 1, the method of the present invention can also be extended to the wafer outbound process and oxygen supply mode switching in maintenance scenarios.

[0070] 1. Outbound Process When a batch of wafers needs to be retrieved, the control system first instructs the stacker crane 5 to retrieve the corresponding carrier ring from the target storage slot of the multi-row rack and deliver it to the handover position of the wafer robot 11. The wafer robot 11 then follows the reverse path of step S104 to transfer the carrier ring from the stacker crane 5 to the docking position of the rotary table assembly 10.

[0071] Subsequently, the rotating docking and sealing door airlock control steps corresponding to step S103 are executed to rotate the carrier ring from "facing the inside of the tunnel" to "facing the outside". The carrier ring is then transferred from the tunnel environment to the external buffer area by alternating opening and closing of the outer and inner doors.

[0072] Finally, the picking robot 2 or other external process equipment receives the carrier ring from the rotary table or loading buffer shelf 3, completing the wafer outbound process.

[0073] 2. Maintenance of oxygen supply mode When personnel need to enter the warehouse for maintenance or adjustment, the control system can execute a maintenance mode: Gradually reduce the nitrogen supply of the gas circulation device and start the oxygen supply module to deliver oxygen or clean air into the storage room through pipelines, so that the internal environment of the storage room meets the safety requirements for personnel operation. In maintenance mode, this method can suspend the automatic transfer process of steps S101 to S104, and only maintain the necessary environmental maintenance and safety monitoring.

[0074] After maintenance is completed, the control system shuts down the oxygen supply module, restarts the nitrogen circulation device, restores the maintenance of the nitrogen environment in step S105, and reactivates the automated transfer process in steps S101 to S104, thus achieving a smooth switch from maintenance mode to nitrogen protection mode.

[0075] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. Other parts of the present invention not described in detail belong to the prior art and will not be elaborated upon here.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A semiconductor wafer nitrogen intelligent storage method, characterized in that, The method is applied to a storage system including a transition purification device, a material taking and placing manipulator, a material loading buffer shelf, a carrier ring rotating table and a rotating table assembly, a sealing door assembly, a wafer manipulator, a lane stacker, a multi-row shelf, a gas circulation device, and an oxygen supply module, and comprises the following steps: Step one, feeding and pre-purification: a wafer box loaded with wafer pieces is sent into the transition purification device through a feeding device, and the air in the feeding area is filtered and purified under the action of the airflow purification unit inside the transition purification device; Step two, buffering and carrier ring arrangement: the material taking and placing manipulator takes out the carrier ring carrier loaded with wafer pieces from the wafer box one by one, and places the carrier ring carrier in the designated storage position of the material loading buffer shelf for buffering, and the material loading buffer shelf is used for orderly storing multiple carrier ring carriers; Step three, rotating connection, posture adjustment, and airlock realization by cooperating with a sealing door: under the control of the control system, the buffered carrier ring carrier is transferred from the material loading buffer shelf to the rotating table on the rotating table assembly at the lane entrance, the rotating table assembly clamps and positions the carrier ring carrier, and drives the rotating table to rotate around the center axis, so that the carrier ring carrier is turned from the direction facing the outside to the direction facing the inside of the lane, and the outer door and the inner door of the sealing door assembly are controlled to be opened and closed alternately, so that the lane entrance is always in the airlock state when the carrier ring carrier enters and exits the lane entrance; Step four, transfer and storage in the lane: when the inner door of the sealing door assembly is opened, the wafer manipulator is controlled to take the carrier ring carrier from the rotating table assembly under the guidance of the sealing guide mechanism, clamp the carrier ring carrier without contacting the surface of the wafer piece, and transfer the carrier ring carrier to the carrier table position of the lane stacker along the lane direction; then the lane stacker is controlled to receive the carrier ring carrier and move along the lane and shelf direction to transport the carrier ring carrier to the designated storage position of the multi-row shelf to complete the warehousing; Step five, nitrogen circulation and environment maintenance: The gas circulation device is used to transport and circulate nitrogen into the storage, so that the temperature-adjusted and purified nitrogen flows through the multi-row shelf area in the form of directional airflow, and the return air is sent back to the gas circulation device for temperature, humidity, and particle filtration.

2. The wafer automated transfer method of claim 1, wherein, In step one, a filter unit and a flow guide duct are arranged inside the transition purification device, the filter unit uses high-efficiency filter material to filter particles in the air entering the feeding area, and the flow guide duct is used to form a directional airflow from top to bottom and / or from back to front, so that the wafer box is always in a purified directional airflow environment before being sent into the material loading buffer shelf through the feeding device.

3. The wafer automated transfer method of claim 1, wherein, In step two, the material loading buffer shelf is a multi-layer structure arranged in the vertical direction, each layer is provided with a positioning storage position for limiting the carrier ring carrier loaded with wafer pieces; the material taking and placing manipulator has a multi-degree-of-freedom grabbing mechanism configured to take out the carrier ring carrier loaded with wafer pieces from the wafer box one by one without contacting the surface of the wafer piece, and place the carrier ring carrier in the positioning storage position in a predetermined order for buffering.

4. The semiconductor wafer nitrogen intelligent storage method according to claim 1, characterized in that, In step three, the cached carrier ring carrier is transferred from the loading cache shelf to the hollow rotary table on the rotary table assembly at the entrance of the lane, the outer edge clamping part and / or the recess positioning structure of the carrier ring carrier are clamped by the clamping assembly, and the sensor assembly detects the in-place state of the carrier ring carrier; After detecting that the carrier ring carrier is in place and clamped stably, the motor pulley assembly drives the hollow rotary table to rotate around its central axis, so that the carrier ring carrier is rotated by about 180° relative to the lane direction, from the external direction to the side of the wafer robot inside the lane, to complete the adjustment of the attitude of the carrier ring carrier and the docking with the transfer direction in the lane.

5. The semiconductor wafer nitrogen intelligent storage method according to claim 4, wherein The clamping assembly comprises at least two sets of oppositely arranged clamping arms, guide columns and linear bearings in sliding connection with the clamping arms, and a gas cylinder assembly connected with the clamping arms, the clamping arms are opened and closed along a predetermined straight line direction under the guidance of the guide columns and linear bearings, and exert a clamping force on the carrier ring carrier under the action of the spring mechanism, thereby maintaining the directional stability of the carrier ring carrier during the rotation of the hollow rotary table by about 180° and improving the repeated positioning accuracy of the clamping and unclamping actions.

6. The semiconductor wafer nitrogen intelligent storage method according to claim 1, wherein In step four, the sealing door assembly comprises an outer door and an inner door arranged outside and inside the entrance of the lane, a sealing panel arranged on the inner surface of the door body, and a sealing assembly arranged between the sealing panel and the edge of the entrance of the lane; When the carrier ring carrier enters from the outside, the outer door is opened and the inner door is closed, after the carrier ring carrier is connected by the rotary table assembly for about 180° rotation, the outer door is closed, and the inner door is opened as needed; The sealing panel is attached to the sealing assembly when the door body is closed, so as to form an airlock structure at the entrance of the lane when the outer door and the inner door are closed respectively, so that the carrier ring carrier is always isolated from the external environment in the state of alternating opening of the outer door and the inner door during the process of entering and leaving the entrance of the lane.

7. The semiconductor wafer nitrogen intelligent storage method according to claim 6, wherein The sealing door assembly further comprises a motor pulley assembly for driving the sealing panel to reciprocate and a limiting assembly for limiting the travel of the sealing panel, the motor pulley assembly comprises a servo motor fixed on the rack and a synchronous belt connected with the sealing panel, the servo motor drives the sealing panel to slide open and close along the guide structure through the synchronous belt, and the limiting assembly is arranged at the end of the guide structure to limit the maximum opening position and the minimum closing position of the sealing panel.

8. The semiconductor wafer nitrogen intelligent storage method according to claim 1, wherein In step four, the wafer robot is installed on the sealing lead screw module, the sealing lead screw module comprises a linear guide rail arranged along the lane direction, a ball screw matched with the linear guide rail, and a linear displacement measurement sensor arranged at the bottom of the sealing lead screw module; The ball screw is used to guide the wafer robot to move transversely along the aisle direction, and the linear displacement measurement sensor is used to detect the displacement position of the wafer robot in the aisle direction in real time and feed back the detection result to the control system, so that the wafer robot can accurately transfer the carrier from the rotating table assembly to the loading position of the aisle stacker in the state of supporting and clamping the outer contour of the carrier.

9. The semiconductor wafer nitrogen intelligent storage method according to claim 1, wherein, In step four, the aisle stacker includes a loading assembly slidingly arranged on the stacker track, and the top of the loading assembly is provided with a clamping part having an arc-shaped clamping surface matched with the shape of the outer edge of the carrier; When the aisle stacker receives the carrier transferred by the wafer robot, the carrier is clamped by the arc-shaped clamping surface in a wrapping manner during the acceleration, deceleration and lifting in the aisle direction and the rack direction, and is transported to the specified storage slot position of the multi-row rack and completes the warehousing.

10. The semiconductor wafer nitrogen intelligent storage method according to claim 1, wherein, In step five, the gas circulation device includes a temperature regulating and purifying assembly, a static pressure tank, an air supply pipe and an air return pipe. The temperature regulating and purifying assembly adjusts the temperature, humidity and particulate matter concentration of the circulating gas. After being uniformly pressurized by the static pressure tank, high-purity nitrogen is sent to the multi-row rack area through the air supply pipe to form a directional air flow from top to bottom and / or from back to front. The air return pipe extracts gas from the bottom of the rack and / or the lower part of the aisle and sends it back to the temperature regulating and purifying assembly, thereby forming a closed-loop gas circulation path. The oxygen supply module is connected with the internal space of the warehouse through a pipeline and is used to supply oxygen or clean air to the internal space of the warehouse instead of nitrogen circulation under the condition of personnel maintenance or other abnormal conditions.

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