Wafer box temporary storage system and storage method

Abstract

This application relates to the field of semiconductor manufacturing equipment technology, specifically to a wafer cassette temporary storage system and storage method. The system includes a housing, multiple storage bays, a vertical multi-segment robotic arm, a nitrogen supply subsystem, and a loading platform. The housing has a loading port on its first side wall and an unloading port on its second side wall. Multiple storage bays are arranged vertically within the housing for temporarily storing wafer cassettes. The vertical multi-segment robotic arm is located within the housing, and its range of motion covers the loading port, unloading port, and all storage bays. The nitrogen supply subsystem includes a main nitrogen pipeline located within the housing and multiple independent branches branching from the main nitrogen pipeline. Each independent branch is connected to a storage bay and has an outlet. The loading platform is fixedly located inside the loading port and has at least one inclined slide rail. The extension direction of the inclined slide rail is spatially offset from the movement trajectory of the vertical multi-segment robotic arm when accessing wafer cassettes on the loading platform.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing equipment technology, and more specifically, to a wafer cassette temporary storage system and storage method. Background Technology

[0002] In advanced semiconductor manufacturing, wafer transfer between front-end processes is usually accomplished using front-end open wafer cassettes. Before and after critical processes (such as annealing and thin film deposition), it is often necessary to temporarily store and buffer the fully loaded wafer cassettes to coordinate the production cycle of different equipment, match production rates, or allow for process waiting. The cleanliness and atmosphere control of this temporary storage stage are crucial. The intrusion of any external particulate contaminants, moisture, or oxidizing gases may lead to wafer surface defects and reduce product yield.

[0003] Existing temporary storage solutions mainly fall into two categories: one is simple cleanroom cabinets or shelving buffer stations, which only provide a relatively clean storage environment. These devices lack active protection for the internal space of the wafer cassette. When the wafer cassette is stored or ready to be transferred to process equipment, its openings are easily exposed to the external environment, posing a risk of cross-contamination. The other category is highly integrated Equipment Front-End Modules (EFEMs), but their design is usually centered around a single process equipment, with limited storage capacity and high cost, making them unsuitable for situations requiring centralized buffering of multiple wafer cassettes.

[0004] In addition, the cleanroom space cost of semiconductor factories is extremely high. Traditional horizontal conveying or horizontal robotic arm grasping methods require a large planar movement space, resulting in large equipment footprint and low space utilization. At the same time, existing temporary storage equipment generally lacks the ability to dynamically and actively seal and re-purify the atmosphere inside the wafer box before it is handed over to the warehouse. It cannot ensure that the internal environment of the wafer box maintains an ultra-high cleanliness and the set inert atmosphere when it leaves the temporary storage system and enters the next interface.

[0005] Therefore, there is an urgent need to develop a wafer cassette temporary storage system that integrates high-density storage, automated transfer, and active cleanliness assurance. Summary of the Invention

[0006] In view of this, in order to solve the above-mentioned problems in the prior art, this application provides a wafer cassette temporary storage system and storage method.

[0007] The embodiments of this application are implemented as follows: In a first aspect, this application provides a wafer cassette temporary storage system, including a housing, multiple storage bays, a vertical multi-segment robotic arm, a nitrogen supply subsystem, and a loading platform: The first side wall of the box is provided with a loading port, and the second side wall is provided with an unloading port; Multiple storage bays are arranged vertically within the enclosure for temporary storage of wafer cassettes; The vertical multi-segment robotic arm is installed inside the box, and its range of motion covers the loading port, the unloading port, and all the storage positions. The nitrogen supply subsystem includes a main nitrogen pipeline installed inside the box and multiple independent branches branching off from the main nitrogen pipeline. Each independent branch is connected to one of the storage positions and is provided with an outlet. The loading platform is fixedly installed inside the loading port, and at least one inclined slide rail is provided on it. The extension direction of the inclined slide rail is spatially offset from the motion trajectory of the vertical multi-segment robotic arm when it accesses the wafer cassette on the loading platform.

[0008] In one possible implementation, an unloading platform is also fixedly provided on the inner side of the unloading port, and a guide rail is provided on the unloading platform.

[0009] In one possible implementation, the vertical multi-segment robotic arm includes a vertical guide rail, a lifting seat, and a telescopic fork arm. The vertical guide rail is fixedly installed inside the housing, the lifting seat is slidably installed on the vertical guide rail, and the telescopic fork arm is installed on the lifting seat for lifting or delivering the wafer cassette.

[0010] In one possible implementation, the outlet of the nitrogen supply subsystem is provided with a pneumatic connector or nozzle for docking or aligning with the gas filling port of the wafer cassette when the wafer cassette is placed in the storage position.

[0011] In one possible implementation, a sensor system is also included, comprising multiple sensors for detecting the presence of wafer cassettes on the loading platform, the unloading platform, and each of the storage locations.

[0012] In one possible implementation, a controller is also included, which is communicatively connected to the vertical multi-segment robotic arm, the nitrogen supply subsystem, and the sensor system, and is configured to perform the following operations: Based on signals from the sensor system, the vertical multi-segment robotic arm is controlled to perform wafer cassette storage and retrieval operations; The nitrogen supply subsystem is controlled to start supplying gas after the wafer is stored in the corresponding storage location and to stop supplying gas before it is removed.

[0013] In one possible implementation, the controller is further communicatively connected to a host production execution system or overhead crane system to receive wafer cassette scheduling instructions.

[0014] In one possible implementation, the angle between the inclined slide rail and the horizontal plane is 10 to 30 degrees.

[0015] Secondly, this application provides a wafer cassette temporary storage system storage method, including: Receiving steps: The wafer cassette is received from the overhead crane system or manually placed through the loading port of the temporary storage system, wherein the wafer cassette is guided to the designated loading position via an inclined slide rail set on the loading port platform; Transfer and storage steps: The wafer cassette located at the designated loading position is transferred to any one of the multiple storage locations within the system for temporary storage using the vertical multi-segment robotic arm inside the temporary storage system. Environmental control steps: During the period when the wafer cassette is temporarily stored in the target storage location, nitrogen is continuously or intermittently supplied to the interior of the wafer cassette through an independent nitrogen pipeline connected to the target storage location; Retrieval and delivery steps: In response to retrieval commands from the annealing process equipment or scheduling system, the wafer cassette temporarily stored in the designated storage location is retrieved by a vertical multi-segment robotic arm and transferred to the unloading port of the temporary storage system for entry into the annealing process equipment.

[0016] In one possible implementation, during the receiving step or the transfer and storage step, when the sensor system detects that a wafer cassette is in place on the loading platform, the controller first controls the vertical multi-segment robotic arm to move to the ready position and pauses. After the robotic arm from the overhead crane system has completely exited the loading port area and received the safety signal it sends, the controller then instructs the vertical multi-segment robotic arm to perform the cassette retrieval action.

[0017] The technical solution provided in this application can achieve at least the following beneficial effects: This application provides a wafer cassette temporary storage system and storage method that integrates high-density storage design, automated seamless interface, and active microenvironment control technology. By constructing an intelligent temporary storage system with vertical spatial layout, independent nitrogen supply, and collaborative avoidance interface, it achieves efficient, clean, and automated management of wafer cassette flow between processes. It solves the problems of large footprint, easy physical interference when connecting with automated material handling systems, and oxidation and contamination risks caused by lack of effective wafer environmental protection in traditional planar temporary storage methods. It changes the previous equipment construction concept that separated storage, transmission, and protection, and establishes a unified solution that integrates buffering, protection, and handover, realizing smooth connection of wafer cassette from handling system to process equipment at the physical flow and information flow levels.

[0018] This wafer cassette storage system is designed to meet the practical needs of efficient wafer cassette storage and stringent environmental control in semiconductor front-end manufacturing, particularly before and after annealing processes. Its vertical robotic arm and storage bay layout can flexibly adapt to different production capacity scales and cleanroom space conditions. Its fixed-point nitrogen supply can precisely meet the differentiated requirements of various processes for the storage atmosphere, providing an efficient and reliable technical means for production line material scheduling and wafer field protection. This system possesses excellent modularity and scalability, enabling rapid adjustment of storage capacity, expansion of functional modules, or updates to control logic based on changes in production line cycle time, additions or removals of process equipment, or technological upgrades. This helps solve problems such as production bottlenecks, difficulties in data traceability, and quality risks caused by traditional storage methods, significantly improving the efficiency of material flow, automation level, and product yield in semiconductor manufacturing. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a wafer cassette temporary storage system according to an exemplary embodiment of this application; Figure 2 This is a schematic diagram of the structure of the open portion of a wafer cassette storage system according to an exemplary embodiment of this application; Figure 3 This is a schematic flowchart illustrating a wafer cassette temporary storage system storage method according to an exemplary embodiment of this application.

[0021] Figure label: 1. Box body; 2. Storage compartment; 3. Vertical multi-segment robotic arm; 4. Nitrogen supply subsystem; 5. Loading platform. Detailed Implementation

[0022] To make the objectives, implementation methods and advantages of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the exemplary embodiments described are only some embodiments of this application, and not all embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0023] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0024] The terms "first," "second," "third," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar or related objects or entities, and do not necessarily imply a specific order or sequence, unless otherwise specified. It should be understood that such terms are interchangeable where appropriate.

[0025] The terms “comprising” and “having”, and any variations thereof, are intended to cover but not exclude inclusion, for example, a product or device that includes a range of components is not necessarily limited to all of the components that are clearly listed, but may include other components that are not clearly listed or that are inherent to such product or device.

[0026] In advanced semiconductor manufacturing, wafer transfer between front-end processes is usually accomplished using front-end open wafer cassettes (wafer cassettes). Before and after critical processes (such as annealing and thin film deposition), it is often necessary to temporarily store and buffer the fully loaded wafer cassettes to coordinate the production cycle of different equipment, match production rates, or allow for process waiting. The cleanliness and atmosphere control of this temporary storage process are crucial. The intrusion of any external particulate contaminants, moisture, or oxidizing gases may lead to wafer surface defects and reduce product yield.

[0027] Existing temporary storage solutions mainly fall into two categories: one is simple cleanroom cabinets or shelving buffer stations, which only provide a relatively clean storage environment. These devices lack active protection for the internal space of the wafer cassette. When the wafer cassette is stored or ready to be transferred to process equipment, its openings are easily exposed to the external environment, posing a risk of cross-contamination. The other category is highly integrated Equipment Front-End Modules (EFEMs), but their design is usually centered around a single process equipment, with limited storage capacity and high cost, making them unsuitable for situations requiring centralized buffering of multiple wafer cassettes.

[0028] In addition, the cleanroom space cost of semiconductor factories is extremely high. Traditional horizontal conveying or horizontal robotic arm grasping methods require a large planar movement space, resulting in large equipment footprint and low space utilization. At the same time, existing temporary storage equipment generally lacks the ability to dynamically and actively seal and re-purify the atmosphere inside the wafer box before it is handed over to the warehouse. It cannot ensure that the internal environment of the wafer box maintains an ultra-high cleanliness and the set inert atmosphere when it leaves the temporary storage system and enters the next interface.

[0029] Therefore, there is an urgent need to develop a wafer cassette temporary storage system that integrates high-density storage, automated transfer, and active cleanliness assurance.

[0030] Next, the technical solutions of this application and how they solve the aforementioned technical problems will be described in detail through embodiments and in conjunction with the accompanying drawings. The embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application.

[0031] In one exemplary embodiment, a wafer cassette storage system is provided. In this embodiment, the wafer cassette storage system may include a housing 1, multiple storage bays 2, a vertical multi-segment robotic arm 3, a nitrogen supply subsystem 4, and a loading platform 5. The first side wall of the box 1 is provided with a loading port, and the second side wall is provided with an unloading port; Multiple storage slots 2 are arranged vertically inside the housing 1 for temporary storage of wafer cassettes; The vertical multi-segment robotic arm 3 is installed inside the housing 1, and its range of motion covers the loading port, the unloading port, and all the storage positions 2; The nitrogen supply subsystem 4 includes a main nitrogen pipeline installed in the housing 1 and multiple independent branches branching off from the main nitrogen pipeline. Each independent branch is connected to a storage position 2 and is provided with an outlet. The loading platform 5 is fixedly installed inside the loading port, and at least one inclined slide rail is provided on it. The extension direction of the inclined slide rail is spatially offset from the motion trajectory of the vertical multi-segment robotic arm 3 when it accesses the wafer cassette on the loading platform 5.

[0032] In one embodiment, such as Figure 1 and Figure 2 As shown, the main body of the wafer storage system is a rectangular box 1 with good airtightness. The box 1 is usually made of stainless steel (such as SUS304) or aluminum alloy with anodized surface. The inner wall is mirrored or passivated to minimize particle adhesion and facilitate cleaning, thereby maintaining the internal cleanliness for a long time.

[0033] The first side wall of the housing 1 has a standard-sized loading port for receiving standard front-opening wafer cassettes (wafer cassettes) placed by a robot arm from the overhead crane system (OHT) or by manual placement. The second side wall has an unloading port, the position, height and interface of which can be customized according to the loading port of downstream process equipment (such as annealing furnace) to ensure smooth physical docking.

[0034] The core of the system, the vertical multi-segment robotic arm 3, is fixedly installed inside the housing 1. Its specific components include: a rigid vertical guide rail fixed to the back or central frame of the housing 1; a lifting platform driven by a servo motor via a ball screw or synchronous belt, capable of precise positioning along the vertical guide rail; and a horizontal telescopic fork mounted on the lifting platform. This telescopic fork is typically driven by another set of servo motors and can extend or retract at a smooth speed curve. Its end effector (fork) surface is covered with an anti-static flexible material (such as silicone or Teflon) to prevent scratching the bottom of the wafer cassette and eliminate the risk of electrostatic adsorption of particles. The range of motion of the vertical multi-segment robotic arm 3 has been precisely calculated and simulated to ensure that its fork can reach the precise positions of the loading port, the unloading port, and all storage positions 2 on both sides of the housing 1 without interference.

[0035] Multiple storage positions 2 are arranged vertically on the left and right side walls inside the housing 1 to form a high-density storage array. Each storage position 2 is essentially a pair of independently adjustable L-shaped support rails. Low-friction coefficient lining strips can be embedded in the inner side of the rails. The support rails are installed on the vertical support column by adjusting screws or pin positioning mechanisms with scale markings. This allows engineers to quickly adjust the height and spacing of the support surface according to the needs of storing different types of wafer cells (such as 200mm / 300mm). The vertical spacing of the storage positions 2 needs to be slightly greater than the height of the wafer cell to leave a safe space for the operation of the vertical multi-segment robotic arm 3.

[0036] The nitrogen supply subsystem 4 includes a nitrogen source (or a centralized gas supply system for the factory) located outside the housing 1, a main nitrogen pipeline located inside the housing 1, and multiple independent branches branching off from the main pipeline. Each independent branch is equipped with an independently controllable precision solenoid valve, a micro-flow meter, and a pressure sensor, forming a closed-loop gas management unit. An outlet is located at the end of each branch. Preferably, this outlet uses a "floating pneumatic connector," which is mounted on a micro-elastic support and has an internal sealing ring. When the wafer cassette is precisely placed in the storage position 2 by the vertical multi-segment robotic arm 3, the connector can adaptively offset within a certain range, ensuring a tight connection with the standard nitrogen filling valve on the back of the wafer cassette, forming a reliable seal. Alternatively, the outlet can also be a "multi-hole diffuser nozzle," whose spray angle and range are designed to effectively introduce nitrogen into the inlet filter area of ​​the wafer cassette without contacting it.

[0037] The loading platform 5 is fixedly installed on the inner bottom of the loading port by a bracket. Its innovative design lies in the two parallel inclined slide rails set on the platform. The cross-section of the inclined slide rail can be designed as "V" or "U" shaped to better guide the flange edge at the bottom of the wafer box. The surface of the slide rail can be hardened or coated with a low-friction coating (such as diamond-like coating). As described in the background art, the extension direction of the inclined slide rail is spatially offset from the movement trajectory of the telescopic fork of the vertical multi-segment robotic arm 3. This is the key to achieving seamless and safe handover. Specifically, the tilt direction of the inclined slide rail is designed so that the sliding path of the wafer box and the path of the vertical multi-segment robotic arm 3 lifting horizontally from the side form a spatial intersection angle. There are no interference points between the two in three-dimensional space, thus achieving true "physical avoidance".

[0038] The angled slide rail on the loading platform 5, with respect to the horizontal plane, forms a specific acute angle. Based on engineering mechanics analysis and practical verification, it is preferably designed to be between 10 and 30 degrees. This angle range is mainly based on considerations of the sliding dynamic characteristics of the wafer cassette (taking a standard 300mm front-opening wafer cassette as an example, whose weight is typically 6-8 kg). When the angle is less than 10 degrees, the downward force component of the wafer cassette due to gravity on the slide rail is insufficient, which may lead to poor sliding or the wafer cassette being unable to slide completely into the preset mechanical positioning point by its own weight, thus requiring external assistance and increasing the system complexity and failure risk. When the angle is greater than 30 degrees, the final velocity of the wafer cassette sliding down will increase significantly, and there is a possibility of non-buffering interaction with the positioning stop. The potential hazards of rigid collisions can cause wafer box attitude deflection, internal wafer vibration, or even structural damage, seriously affecting the positioning accuracy and product safety of subsequent vertical multi-segment robotic arm pick-up and drop. Through motion simulation and physical testing, it was found that within this angle range, a fully loaded wafer box can glide smoothly and controllably into position under its own weight. The final kinetic energy can be effectively absorbed by the buffer material (such as polyurethane pad) at the positioning point, ensuring that the handover process is both efficient and reliable. In practical engineering applications, an optimal value is often selected within this range based on the specific wafer box model, weight, and repeatability of the crane placement. For example, for most application scenarios, 15 to 25 degrees is a common choice that balances efficiency and safety.

[0039] Furthermore, a similarly structured unloading platform is fixedly installed inside the unloading port, on which an ejection mechanism driven by a cylinder or motor, or a simple guide roller, can be installed to assist the wafer cassette in smoothly transitioning to downstream equipment.

[0040] The system also includes a distributed sensor system and a programmable logic controller (PLC) or industrial computer (IPC) as the control core. The sensor system includes: photoelectric sensors or pressure sensors installed on the loading platform 5 and the unloading platform to detect whether the wafer cassette has reached the designated handover position; microswitches or photoelectric sensors installed under the support structure of each storage position 2 to detect whether there is a wafer cassette at that position; and temperature, humidity, and particulate matter sensors that may be set at key locations inside the housing 1 to monitor the environment inside the housing.

[0041] The controller is connected to all drive motors of the vertical multi-segment robotic arm 3, all solenoid valves and sensors of the nitrogen supply subsystem 4, the entire sensor system, and the factory's supervisory control system (MES) or overhead crane control system. The controller is configured to execute complex scheduling logic, such as dynamically allocating target storage bits based on the occupancy status of storage bit 2, process priority, first-in-first-out (FIFO) rules, or instructions from the MES.

[0042] Of particular importance is that, to achieve a high degree of safe coordination with the overhead crane system, a hard-wired safety interlock signal (such as a set of safety relay circuits) and / or a secure communication protocol based on real-time industrial Ethernet are established between the controller and the overhead crane system. The specific coordination process is as follows: When the sensors of the loading platform 5 detect that the wafer cassette is in place, the controller first moves the vertical multi-segment robotic arm 3 to a "safe ready position" away from the loading port and pauses it. At the same time, it sends a confirmation signal of "wafer cassette detected" to the overhead crane system. The controller continues to wait to receive a safety clearance signal from the overhead crane system that "the robotic arm has been fully retracted and locked". Only after receiving this safety signal will the interlock logic inside the controller be released, allowing the vertical multi-segment robotic arm 3 to perform the subsequent cassette picking action, thereby fundamentally eliminating the risk of mechanical interference.

[0043] Corresponding to the aforementioned embodiments of the wafer cassette temporary storage system, this application also provides an embodiment of a storage method for the wafer cassette temporary storage system.

[0044] In one exemplary embodiment, such as Figure 3 As shown, a storage method for a wafer cassette temporary storage system is provided, which may include the following steps: Step 100: Receiving step, receiving a wafer cassette from the overhead crane system or placed manually through the loading port of the temporary storage system, wherein the wafer cassette is guided to the designated loading position via an inclined slide rail set on the loading port platform.

[0045] Step 200: Transfer and storage step, using the vertical multi-segment robotic arm 3 inside the temporary storage system, the wafer cassette located at the designated loading position is transferred to any one of the multiple storage locations 2 inside the system for temporary storage.

[0046] Step 300: Environmental control step, during the period when the wafer cassette is temporarily stored in the target storage location, nitrogen is continuously or intermittently supplied to the interior of the wafer cassette through an independent nitrogen pipeline connected to the target storage location.

[0047] Step 400: Retrieval and delivery step, in response to the retrieval command from the annealing process equipment or scheduling system, the wafer cassette temporarily stored in the designated storage location 2 is retrieved by the vertical multi-segment robotic arm 3 and transferred to the unloading port of the temporary storage system so that it can enter the annealing process equipment.

[0048] In one embodiment, the specific implementation method of the wafer cassette temporary storage system is as follows: The overhead crane system transports the wafer cassette containing the wafers to the outside of the loading port of the temporary storage system. The crane's robotic arm releases the wafer cassette onto the high end of the inclined slide rail, and the wafer cassette slides along the rail into the box until it triggers the first photoelectric sensor on the loading platform 5. The sensor signal is sent to the controller, marking the completion of "reception".

[0049] After receiving the sensor signal, the controller allocates an idle "target storage position" to the wafer cassette according to the preset scheduling strategy. Then, the controller instructs the vertical multi-segment robotic arm 3 to move: the lifting seat moves to the loading port height, the telescopic fork extends horizontally, and due to the avoidance design of the inclined slide rail, the fork can extend into the bottom of the wafer cassette without obstruction. Then, it lifts and supports the wafer cassette, retracts the fork, and then the lifting seat carries the wafer cassette to the height of the target storage position. The telescopic fork extends again and accurately places the wafer cassette on the support rail of the storage position 2. The state of the second photoelectric sensor on the storage position 2 changes, confirming successful storage.

[0050] Once the controller confirms through the sensor that the wafer cassette is in place in storage position 2, it immediately sends a command to the nitrogen supply subsystem 4 to open the precision solenoid valve on the independent branch leading to storage position 2. High-purity nitrogen is then injected into the wafer cassette through a pneumatic connector or nozzle to maintain a slightly positive pressure inert gas environment inside until the wafer cassette is removed.

[0051] When the annealing process equipment is ready or a specific wafer cassette needs to be removed according to the production scheduling instructions, the controller sends a command to the vertical multi-segment robotic arm 3. The vertical multi-segment robotic arm 3 moves to the designated storage position 2, removes the target wafer cassette, and then transfers it to the unloading port. The vertical multi-segment robotic arm 3 places the wafer cassette on the guide rail of the unloading platform, and then it is picked up by the loading mechanism of the annealing equipment itself, or the wafer cassette slides into the equipment port along the rail, thus being "sent out" and entering the next annealing process.

[0052] In one embodiment, to achieve highly reliable and seamless safe collaborative operation with the crane system, the communication and safety interlocking mechanism between the controller and the crane system is crucial. This mechanism is specifically implemented as follows: When the sensor system (such as the photoelectric sensor on the loading platform 5) detects that the wafer cassette is in the designated loading position, the controller first controls the vertical multi-segment robotic arm 3 to move to a preset "ready waiting position" (for example, the telescopic fork arm retracts and the lifting seat moves to a position slightly higher than the loading port), and pauses at this position.

[0053] The controller will not immediately execute the box retrieval action, but will instead enter a "waiting for external safety clearance" state. In this state, the controller continuously monitors the communication interface, waiting for a safety signal from the overhead crane system that "placement is complete and the robot arm has completely withdrawn from the interference area". This safety signal is usually issued by the overhead crane controller after its robot arm has completed the placement action, confirmed that the gripper has been released, and driven the robot arm to completely retract to the safe space outside the loading port of the temporary storage system. This set of signals can be implemented through a "safety interlock" signal of hard-wired (such as digital I / O) or through specific safety messages transmitted via real-time industrial Ethernet (such as EtherCAT, PROFINET).

[0054] Only after the controller confirms receipt of this safety signal will the internal motion prohibition logic be released, and the vertical multi-segment robotic arm 3 will be instructed to perform the subsequent box-picking action. This collaborative anti-collision control strategy based on clear safety signals strictly follows the safety standards for integrated automation equipment (such as SEMIS2 / S8), fundamentally eliminating the possibility of spatial motion interference between the overhead crane robotic arm and the vertical multi-segment robotic arm 3 inside the temporary storage system. It is one of the core guarantees for achieving continuous and safe "lights-out operation" of the fully automated production line.

[0055] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially as indicated, these steps are not necessarily executed in the indicated order. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps.

[0056] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0057] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application.

Claims

1. A wafer cassette staging system, comprising: Includes a housing, multiple storage compartments, a vertical multi-segment robotic arm, a nitrogen supply subsystem, and a loading platform. The first side wall of the box is provided with a loading port, and the second side wall is provided with an unloading port; Multiple storage bays are arranged vertically within the enclosure for temporary storage of wafer cassettes; The vertical multi-segment robotic arm is installed inside the box, and its range of motion covers the loading port, the unloading port, and all the storage positions. The nitrogen supply subsystem includes a main nitrogen pipeline installed inside the box and multiple independent branches branching off from the main nitrogen pipeline. Each independent branch is connected to one of the storage positions and is provided with an outlet. The loading platform is fixedly installed inside the loading port, and at least one inclined slide rail is provided on it. The extension direction of the inclined slide rail is spatially offset from the motion trajectory of the vertical multi-segment robotic arm when it accesses the wafer cassette on the loading platform.

2. The FOUP staging system of claim 1, wherein, An unloading platform is also fixedly installed on the inner side of the unloading port, and a guide rail is provided on the unloading platform.

3. The FOUP staging system of claim 1, wherein, The vertical multi-segment robotic arm includes a vertical guide rail, a lifting seat, and a telescopic fork arm. The vertical guide rail is fixedly installed inside the housing, the lifting seat is slidably installed on the vertical guide rail, and the telescopic fork arm is installed on the lifting seat for lifting or delivering the wafer cassette.

4. The FOUP staging system of claim 1, wherein, The nitrogen supply subsystem is equipped with a pneumatic connector or nozzle at its outlet, which is used to connect or align with the gas filling port of the wafer cassette when the wafer cassette is placed in the storage position.

5. The FOUP staging system of claim 2, wherein, It also includes a sensor system comprising multiple sensors for detecting the presence of wafer cassettes on the loading platform, the unloading platform, and each of the storage locations.

6. The FOUP staging system of claim 5, wherein, It also includes a controller, which is communicatively connected to the vertical multi-segment robotic arm, the nitrogen supply subsystem, and the sensor system, and is configured to perform the following operations: Based on signals from the sensor system, the vertical multi-segment robotic arm is controlled to perform wafer cassette storage and retrieval operations; The nitrogen supply subsystem is controlled to start supplying gas after the wafer is stored in the corresponding storage location and to stop supplying gas before it is removed.

7. The FOUP staging system of claim 6, wherein, The controller is further connected to the host production execution system or the overhead crane system to receive wafer cell scheduling instructions.

8. The FOUP staging system of claim 1, wherein, The angle between the inclined slide rail and the horizontal plane is 10 to 30 degrees.

9. A wafer cassette temporary storage system storage method applied to the wafer cassette temporary storage system of any one of claims 1-8, characterized in that, include: Receiving steps: The wafer cassette is received from the overhead crane system or manually placed through the loading port of the temporary storage system, wherein the wafer cassette is guided to the designated loading position via an inclined slide rail set on the loading port platform; Transfer and storage steps: The wafer cassette located at the designated loading position is transferred to any one of the multiple storage locations within the system for temporary storage using the vertical multi-segment robotic arm inside the temporary storage system. Environmental control steps: During the period when the wafer cassette is temporarily stored in the target storage location, nitrogen is continuously or intermittently supplied to the interior of the wafer cassette through an independent nitrogen pipeline connected to the target storage location; Retrieval and delivery steps: In response to retrieval commands from the annealing process equipment or scheduling system, the wafer cassette temporarily stored in the designated storage location is retrieved by a vertical multi-segment robotic arm and transferred to the unloading port of the temporary storage system for entry into the annealing process equipment.

10. The wafer cassette temporary storage system storage method as described in claim 9, characterized in that, In the receiving step or the transfer and storage step, when the sensor system detects that a wafer cassette is in place on the loading platform, the controller first controls the vertical multi-segment robotic arm to move to the ready position and pauses. After the robotic arm from the overhead crane system has completely exited the loading port area and received the safety signal it sent, the controller then instructs the vertical multi-segment robotic arm to perform the cassette retrieval action.

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