Wireless magnetic levitation wafer carrier device and control method thereof

Abstract

The application provides a wireless magnetic levitation wafer conveying device and a control method thereof, and belongs to the technical field of semiconductor manufacturing equipment. The device comprises a stator, a stator coil array arranged on the stator, a mover arranged above the stator and maintaining a preset air gap with the stator, a permanent magnet array arranged at the bottom of the mover, and the electromagnetic interaction between the stator coil array and the permanent magnet array realizes non-contact suspension and planar motion. The wireless charging system comprises a transmitting coil arranged on the stator and a receiving coil arranged on the mover, and provides electric energy for the mover through electromagnetic coupling. The battery module is installed on the mover and is used for storing electric energy from the receiving coil. The lifting mechanism is powered by the battery module and is installed on the mover. The wafer clamping device is installed on the lifting mechanism. The application can realize non-contact motion and minimize particle contamination. Through wireless charging and battery power supply, the reliability is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic levitation planar motor technologies, and in particular to a wireless magnetic levitation wafer handling device and a control method thereof. Background Art

[0002] With the rapid development of the semiconductor industry and the continuous advancement of Moore's Law, chip process sizes have entered the nanometer era, and wafer sizes have also developed from 6 inches to 12 inches. Against this background, the handling of wafers between various processes in the semiconductor manufacturing process has become a key link, which directly affects product yield and production efficiency. Current semiconductor manufacturing equipment is developing towards intelligence, non-contact, and high precision, which puts more stringent technical requirements on the cleanliness, accuracy and flexibility of handling devices.

[0003] At present, wafer handling technology mainly relies on robotic arm handling systems, which are currently the most widely used technical solution. Patent CN114227671A discloses a wafer transfer robot arm, which adopts a multi-joint structure and a cable-driven mode, and can achieve high-precision positioning and complex motion trajectories; however, the mechanical arm structure of this type of system is complex, occupies a large space, and mechanical friction during its movement is prone to generate particle contamination.

[0004] Robotic arm handling systems integrate cables or air pipes. The robotic arm for wafer adsorption and semiconductor equipment disclosed in Patent CN217544571U uses a vacuum chuck to adsorb wafers. However, the integrated cables and air pipes may limit the range of motion of the robotic arm, and the integration of multiple pipelines and cables will also increase the complexity of later maintenance.

[0005] Robotic arm handling systems rely on mechanical systems to achieve high precision. The wafer transfer robotic arm disclosed in Patent CN117984337A provides a robotic arm with a higher overall folding-deployment ratio, which enables a larger arrangeable space range for the wafer cassette. However, the high precision of the robotic arm depends on the mechanical structure, and the mechanical structure has influencing factors such as wear, which may affect the long-term retention capability of the robotic arm's precision.

[0006] However, the prior art faces the following key technical challenges:

[0007] First, particle contamination control is becoming increasingly severe. Existing mechanical handling methods inevitably generate mechanical friction during movement. When the process size is reduced to 7nm and below, particles with a diameter exceeding 1 / 10 of the process size may cause device failure. Traditional contact motion methods have bottlenecks under the increasingly stringent requirements of ultra-clean environments, and there is an urgent need to develop non-contact handling technologies.

[0008] Second, the flexibility of system layout is constrained. Existing devices generally rely on fixed cables and pipes for power and air supply, and these physical connections limit the system's layout flexibility and freedom of movement. In the context of semiconductor production lines requiring frequent adjustments and rapid reconfiguration, traditional wired systems are unable to support the high-quality development demands of flexible manufacturing.

[0009] Third, the conflict between high precision and long-term stability is prominent. As wafer size increases and pattern precision improves, the required handling and positioning accuracy reaches the sub-micron level. Existing technologies rely on mechanical transmission chains to achieve precise positioning, but factors such as wear, clearance, and thermal drift in the mechanical system affect the ability to maintain long-term accuracy, creating a technical contradiction between high precision requirements and long-term reliability.

[0010] In summary, traditional wafer handling technology can no longer meet the technical requirements of advanced semiconductor manufacturing. There is an urgent need to develop a new handling technology that integrates contactless motion, wireless power supply, and high-precision control in order to break through existing technical bottlenecks and promote the advancement of semiconductor manufacturing equipment technology. Summary of the Invention

[0011] The purpose of this invention is to address the problems of particulate contamination, cable entanglement, low positioning accuracy and low space utilization in existing wafer handling technologies, and to provide a wireless magnetic levitation wafer handling device that enables contactless, high-degree-of-freedom and wireless wafer handling.

[0012] To achieve the above objectives, the present invention adopts the following technical solution:

[0013] On one hand, the present invention provides a wireless magnetic levitation wafer handling device, comprising:

[0014] Stator, wherein a stator coil array is disposed on the stator;

[0015] The mover is positioned above the stator and maintains a preset air gap with the stator. A permanent magnet array is provided at the bottom of the mover. Non-contact levitation and planar motion are achieved through the electromagnetic interaction between the stator coil array and the permanent magnet array.

[0016] A wireless charging system includes a transmitting coil disposed on the stator and a receiving coil disposed on the mover, which provides electrical energy to the mover through electromagnetic coupling.

[0017] A battery module, mounted on the mover, is used to store electrical energy from the receiving coil;

[0018] The lifting mechanism, powered by the battery module and mounted on the mover, is used to drive the wafer clamping device to move up and down.

[0019] A wafer clamping device is mounted on the lifting mechanism and is used to clamp and release wafers.

[0020] Furthermore, the preset air gap between the mover and the stator is 200μm~1000μm.

[0021] Furthermore, the permanent magnet array is arranged in a periodic structure, with each period consisting of an odd number of permanent magnets.

[0022] Furthermore, the battery module includes a lithium battery pack formed by connecting 8 to 12 lithium battery cells and a battery management circuit board. The battery management circuit board is equipped with a predictive charging management algorithm, which first collects battery pack voltage, current and temperature data in real time, and then uses the ampere-hour integral method and voltage lookup table method to accurately calculate the remaining power SOC and health status; it then builds a model based on historical energy consumption data to predict the energy consumption requirements of the task to be executed; when the power is below 15%, it triggers an emergency mode to force charging; when it is below 25%, it issues a warning and stops accepting orders after the current task ends; when it is below 40% and is during task breaks or low production periods, it takes advantage of the off-peak period to perform charging.

[0023] Furthermore, the stator coil array is arranged in a grid pattern, and the stator coils adopt a three-phase winding.

[0024] Furthermore, both the transmitting coil and the receiving coil are planar helical structures.

[0025] Furthermore, the lifting mechanism includes a vertical guide device and a lifting drive device powered by the battery module. The vertical guide device consists of a top plate, a bottom plate, and two vertical guide rails. The top plate is disposed on the vertical guide rails, and the bottom plate is disposed below the vertical guide rails. The lifting drive device includes a linear motor, a ball screw, and a lifting plate. The linear motor is disposed between the top plate and the bottom plate. The lifting plate is sleeved on the vertical guide rails via sliding bearings. The vertical guide rails on the lifting plate move up and down. The linear motor drives the ball screw to move the lifting plate.

[0026] Furthermore, the wafer clamping device includes a clamping base and a clamping jaw unit. The clamping jaw unit is used to clamp the edge of the wafer. The clamping base is mounted on a lifting drive device. The clamping jaw unit is fixed on the clamping base for clamping the edge of the wafer. The clamping jaw unit includes a clamping jaw body, a hydraulic cylinder, a liquid distribution box, a liquid guiding groove, and clamping fingers. The clamping fingers are provided at the end of the clamping jaw body. The output end of the hydraulic cylinder is connected to the liquid distribution box. The output end of the liquid distribution box is connected to the clamping fingers through the liquid guiding groove.

[0027] Furthermore, it also includes a position detection system, which comprises an array of Hall sensors distributed on the surface of the stator and an optical encoder mounted on the mover.

[0028] A control method for a wireless magnetic levitation wafer handling device includes the following steps:

[0029] S1: Load wafer parameters and process flow data, initialize control parameters, and detect mover position and battery status;

[0030] S2: Control the mover to move to the wafer position via magnetic levitation;

[0031] S3: Control the lifting mechanism to descend so that the wafer clamping device is aligned with the target wafer, and start the wafer clamping device to grab the wafer; optical sensors and force sensors monitor the grabbing status in real time;

[0032] S4: Control the lifting mechanism to rise to a safe height, and control the moving part to move to the target position;

[0033] S5: After the mover is precisely positioned to the target position, the lifting mechanism is controlled to descend and release the wafer, bringing the wafer close to the target position. After the correct alignment is detected, the wafer is released smoothly.

[0034] S6: When the battery level is below a preset threshold, control the mover to move to the charging position for wireless charging.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) Effectively solves the problem of particulate contamination. This invention uses magnetic levitation technology to achieve non-contact movement between the mover and the stator, avoiding particulate contamination caused by mechanical friction. Compared with the wear particles generated during the movement of traditional mechanical handling methods, this invention significantly reduces the sources of particle generation by maintaining a constant air gap through non-contact movement, which can meet the stringent requirements of advanced processes for a clean environment and significantly improve the cleanliness level of the wafer handling process.

[0037] (2) Significantly improves system flexibility. This invention, by integrating wireless charging and battery power technology, eliminates the physical constraints of cables and pipes. The mover can move flexibly on the stator plane, breaking through the limitations of traditional robotic arm workspace and giving the wafer cassette layout greater design freedom. Compared to the complex process of rewiring required when adjusting the production line in traditional wired systems, this invention can quickly adapt to changes in production processes, improving space utilization efficiency and system reconfiguration capabilities.

[0038] (3) Improved precision control stability. This invention adopts a magnetic levitation direct drive method, which reduces the impact of factors such as gear backlash and bearing wear on precision in traditional mechanical transmission chains. Through the combination of permanent magnet array design and precision position detection system, sub-micron level positioning accuracy can be achieved. The control system adopts a feedforward-feedback control strategy, which effectively suppresses external interference and system nonlinear factors, improves the accuracy maintenance capability during long-term operation, and alleviates the technical contradiction between high precision and long-term stability in traditional mechanical systems.

[0039] Instruction manual illustrations

[0040] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0041] Figure 2 This is a schematic diagram of the structure of a magnetically levitated mover;

[0042] Figure 3 A schematic diagram illustrating the working principle of a magnetic levitation motor and a wireless charging system;

[0043] Figure 4 This is a comparison diagram of the present invention and a traditional robotic arm for material handling;

[0044] Figure 5 A schematic diagram of cluster control for multi-device collaborative operation;

[0045] Figure 6 This is a diagram of the gripper structure of the present invention.

[0046] Figure 7 A flowchart of the wafer grabbing process;

[0047] Figure 8 This is a flowchart of the system initialization process of the present invention;

[0048] Figure 9 This is a flowchart of the wafer gripping stage of the present invention;

[0049] Figure 10 This is a flowchart of the wafer handling stage of the present invention;

[0050] Figure 11 This is a flowchart of the wafer release stage of the present invention;

[0051] Figure 12 This is a flowchart illustrating the power monitoring and charging management process of the present invention.

[0052] The meanings of the labeled components in the diagram are as follows:

[0053] 1-Stator; 2-Motor; 3-Wireless charging transmitting coil; 4-Wireless charging receiving coil; 5-Battery pack; 6-Lifting device; 7-Wafer clamping device; 8-Motor; 9-Wafer handling device; 10-Wafer box; 11-Stator coil; 21-Motor permanent magnet array; 31-Ferrite core; 41-Ferrite core; 61-Ball screw; 62-Vertical guide rail; 63-Lifting plate; 64-Top plate; 65-Bottom plate; 71-Hydraulic cylinder; 72-Liquid separator; 73-Liquid guide groove; 74-Clamping finger; 91-Traditional robotic arm wafer handling device; 92-Magnetic levitation wafer handling device. Detailed Implementation

[0054] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0055] It should be understood that the following detailed description is exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art.

[0056] Please see Figures 1 to 11 The present invention provides an embodiment: a wireless magnetic levitation wafer transport device, comprising:

[0057] Stator, wherein a stator coil array is disposed on the stator;

[0058] The mover is positioned above the stator and maintains a preset air gap with the stator. A permanent magnet array is located at the bottom of the mover. Non-contact levitation and planar motion are achieved through the electromagnetic interaction between the stator coil array and the permanent magnet array. The stator coil array is arranged in a grid pattern, using a three-phase drive method, with a coil spacing of 20mm~40mm. The permanent magnet array of the mover is composed of N45~N52 grade neodymium iron boron permanent magnet material, with permanent magnet dimensions of 8mm×8mm×2mm. They are arranged in a five-magnet-per-cycle structure, with each cycle consisting of an odd number of permanent magnets. Adjacent magnetization directions form a 90° angle, and the magnetization directions are vertically upward, horizontally to the right, vertically downward, horizontally to the left, and vertically upward, respectively. The surface of the permanent magnets is treated with anti-corrosion coating, and an air gap of 200μm~1000μm is formed between the mover and the stator.

[0059] The wireless charging system includes a transmitting coil disposed on the stator and a receiving coil disposed on the mover, providing electrical energy to the mover via electromagnetic coupling; both are planar helical structures, such as... Figure 3 , Figure 4As shown, the transmitting coil is embedded in a preset area under the stator, and the receiving coil is fixedly installed on the bottom surface of the mover. The outer diameter of the receiving coil is smaller than that of the transmitting coil, the operating frequency is 80~90kHz, the coil diameter is 100mm~200mm, and the number of turns is 15~25; the receiving coil diameter is 80mm~150mm, the number of turns is 10~20, and it is equipped with a synchronous rectification circuit and a charging management chip.

[0060] A battery module, mounted on the mover, is used to store electrical energy from the receiving coil;

[0061] The lifting mechanism, powered by the battery module and mounted on the mover, is used to drive the wafer clamping device to move up and down.

[0062] A wafer clamping device is mounted on the lifting mechanism and is used to clamp and release wafers.

[0063] Please continue reading. Figures 1 to 11 As shown, in one embodiment of the present invention, the preset air gap between the mover and the stator is 200μm~1000μm.

[0064] Please continue reading. Figure 2 As shown, in one embodiment of the present invention, the permanent magnet array is arranged in a periodic structure, and each period consists of an odd number of permanent magnets.

[0065] Please continue reading. Figures 1 to 11 As shown, in one embodiment of the present invention, the battery module includes a lithium battery pack formed by connecting 8 to 12 lithium battery cells and a battery management circuit board. The battery management circuit board is equipped with a predictive charging management algorithm, which first collects the battery pack voltage, current and temperature data in real time, and accurately calculates the remaining power SOC and health status by integrating the ampere-hour integral method and the voltage lookup table method; it then builds a model based on historical energy consumption data to predict the energy consumption requirements of the task to be executed; when the power is below 15%, it triggers an emergency mode to force charging; when it is below 25%, it issues a warning and stops accepting orders after the current task ends; when it is below 40% and is in a task gap or production off-peak period, it takes advantage of the idle period to perform charging. The lithium battery pack has a rated voltage of 18V~36V and a rated capacity of 1500mAh~3000mAh, used to store electrical energy from the receiving coil. The predictive charging management algorithm is based on a closed-loop architecture of "sensing-decision-execution," with the core decision logic employing tiered threshold management: when the battery level is below 15%, an emergency mode is triggered for forced charging; below 25%, a warning is issued and order taking stops after the current task ends; below 40% and during task breaks or low-peak production periods, charging is performed during idle periods. This mechanism ensures that the motor maintains a high production cycle while avoiding the risk of downtime due to power outages.

[0066] Please continue reading. Figure 3 As shown, in one embodiment of the present invention, the stator coil array is arranged in a grid pattern, and the stator coil adopts a three-phase winding.

[0067] Please continue reading. Figure 3 As shown, in one embodiment of the present invention, both the transmitting coil and the receiving coil are planar spiral structures.

[0068] Please continue reading. Figures 1 to 5 As shown, in one embodiment of the present invention, the lifting mechanism includes a vertical guide device and a lifting drive device powered by the battery module. The vertical guide device consists of a top plate, a bottom plate, and two vertical guide rails. The top plate is disposed on the vertical guide rails, and the bottom plate is disposed below the vertical guide rails. The lifting drive device includes a linear motor, a ball screw, and a lifting plate. The linear motor is disposed between the top plate and the bottom plate. The lifting plate is sleeved on the vertical guide rails via sliding bearings. The vertical guide rails on the lifting plate move up and down. The linear motor drives the ball screw to move the lifting plate. The linear motor drives the ball screw to rotate, and the ball screw, sleeved on the lifting plate, enables the lifting plate to move up and down on the vertical guide rails, thereby driving the wafer clamping device to move up and down. The lifting stroke is 50mm~200mm, and the lifting speed is adjustable from 10mm / s to 100mm / s.

[0069] Please continue reading. Figures 1 to 5 As shown, in one embodiment of the present invention, the wafer clamping device includes a clamping base and a clamping jaw unit. The clamping jaw unit is used to clamp the edge of the wafer. The clamping base is mounted on a lifting drive device, and the clamping jaw unit is fixed on the clamping base for clamping the edge of the wafer. The clamping jaw unit includes a jaw body, a hydraulic cylinder, a liquid distribution box, a liquid guide groove, and clamping fingers. The clamping fingers are provided at the end of the jaw body. The output end of the hydraulic cylinder is connected to the liquid distribution box, and the output end of the liquid distribution box is connected to the clamping fingers through the liquid guide groove. The clamping jaw unit does not directly contact the front and back sides of the wafer. The clamping base has a fork-shaped structure, and the clamping jaw unit is embedded in a preset area of ​​the clamping base. The jaw body has a Y-shaped structure and is the main skeleton of the clamping jaw unit, which integrates a hydraulic drive mechanism. The jaw body is made of titanium alloy or aluminum alloy and the surface is anodized.

[0070] First, the hydraulic cylinder generates hydraulic pressure as a power source; then, this pressure enters the distribution box, which distributes the pressure evenly to each path; next, the guide groove serves as a transmission channel, precisely transmitting the pressure to the end gripper finger; finally, the internal chamber of the gripper finger expands and deforms under hydraulic pressure, and this physical deformation allows the gripper finger to firmly clamp the edge of the wafer, thereby achieving flexible and stable gripping. A three-point gripping mechanism is used, with three gripper fingers achieving stable clamping of the wafer.

[0071] Please continue reading. Figures 1 to 5 As shown, in one embodiment of the present invention, a position detection system is further included, the position detection system comprising a Hall sensor array distributed on the surface of the stator and an optical encoder mounted on the mover.

[0072] Please see Figures 1 to 11 The present invention provides another embodiment: a control method for a wireless magnetic levitation wafer handling device, characterized by comprising the following steps:

[0073] S1: Load wafer parameters and process flow data, initialize control parameters, and detect mover position and battery status; this step initializes the wafer position detection system to ensure there are no foreign objects in the working area.

[0074] S2: Control the mover to move to the wafer position via magnetic levitation;

[0075] S3: The lifting mechanism descends to align the wafer clamping device with the target wafer, and the wafer clamping device is activated to grip the wafer; optical and force sensors monitor the gripping status in real time; the device moves to the vicinity of the wafer cassette via a moving plane for precise positioning; the lifting mechanism descends to an appropriate height to align the wafer clamping device with the target wafer; the wafer clamping device is activated to achieve stable wafer gripping; optical and force sensors monitor the gripping status in real time; wafer gripping is completed.

[0076] S4: Control the lifting mechanism to rise to a safe height, and control the mover to move to the target position; the lifting mechanism rises to a safe height; the mover platform moves to the target position according to the optimized path. The generation of the optimized path begins with the control system performing global static planning based on the coordinates of the start and end points of wafer handling, using the shortest path algorithm to initially calculate the theoretically optimal route, and then incorporating a dynamic real-time optimization mechanism. Motion channels are allocated through multi-device collaborative TDMA (Time Division Multiple Access) technology to avoid collisions, and the attitude monitoring system provides real-time feedback on wafer vibration and tilt status, dynamically adjusting motion parameters or local paths. Simultaneously, S-shaped acceleration and deceleration curve planning ensures the smoothness of the handling process, ultimately forming an intelligent path that integrates shortest distance, obstacle avoidance safety, and stable motion. The attitude monitoring system includes force sensors and optical sensors, both located on the upper side of the gripper unit at the contact point with the wafer. During handling, the attitude monitoring system monitors the wafer tilt and vibration status in real time, adjusting motion parameters as necessary; the handling speed and acceleration are dynamically adjusted according to wafer characteristics and process requirements; thus achieving wafer handling.

[0077] S5: After the mover is precisely positioned to the target location, the lifting mechanism is controlled to descend, releasing the wafer and bringing it close to the target position. After correct alignment is detected, the wafer is released smoothly. The mover is precisely positioned to the target location; the lifting mechanism descends slowly, bringing the wafer close to the target position; after the system detects correct alignment, the wafer is released smoothly; the optical sensor confirms that the wafer has been correctly placed; the wafer is released.

[0078] S6: When the battery level is below a preset threshold, the controller moves the mover to the charging position for wireless charging. Based on mature battery management system hardware and algorithms, key parameters such as battery voltage, current, and temperature are collected in real time. Existing algorithms such as ampere-hour integration and voltage lookup table are used to process this data to accurately calculate the remaining battery level, predict the range, and determine the battery health status. Based on the real-time monitoring of the battery status by the battery management system, the battery status is continuously monitored. When the battery level is below the preset threshold or during a task interval, the main controller responds immediately. It first calls global map data and real-time positioning information, calculates the optimal path to the charging area through a path planning algorithm, and then precisely controls the current of the stator coil array to drive the mover permanent magnet array to generate electromagnetic thrust, so that the mover moves smoothly along the planned path. Finally, the wireless charging system is automatically triggered to enter the charging process. The whole process forms a complete "perception-decision-execution" closed loop.

[0079] During system initialization, the position coordinates of the mover are detected and calibrated using a Hall sensor array and an optical encoder, achieving a positioning accuracy within 0.5μm. The voltage, current, and remaining charge of the lithium battery pack are read through the battery management circuit board. In step S2, the clamping force is monitored in real time by a force sensor and controlled within a set range. In step S3, the wafer tilt and vibration status are monitored in real time by an attitude monitoring system, and the handling speed and acceleration are dynamically adjusted according to the wafer characteristics.

[0080] When the battery level is below a preset threshold, the control unit moves to the area above the transmitting coil and starts the wireless charging circuit for electromagnetic coupling charging. The charging management chip controls the charging process, which includes constant current charging, constant voltage charging, and trickle charging. The device has four working modes: high precision mode, high speed mode, energy-saving mode, and emergency handling mode, which can be switched according to different handling requirements.

[0081] Example 1

[0082] like Figure 1 As shown, the magnetic levitation planar motor wafer handling device integrating wireless charging and lifting mechanism of the present invention mainly includes: a stator 1 part with an integrated magnetic levitation stator coil 11 array, a mover 2 part with an integrated permanent magnet array 21, a wireless charging system, a self-powered lifting mechanism, a wafer clamping device, and an intelligent control system.

[0083] The magnetic levitation stator coils 11 are arranged in a grid pattern on the stator 1, forming the basis for planar motion. The stator coils 11 employ a three-phase winding design, generating a controllable magnetic field distribution by controlling the energizing state and current magnitude of each phase coil. The coil array 11 is arranged according to a specific topology, forming repeating units. Each repeating unit contains six coils, each connected to a different phase of the three-phase power supply. The coils internally use multi-strand stranded wire to reduce high-frequency losses, and the outer layer is covered with a polyimide insulation layer, providing good chemical stability and resistance to corrosion from semiconductor processing gases.

[0084] like Figure 2 As shown, the bottom of the mover 2 section is designed with a permanent magnet array 21, made of NdFeB material (preferably N45-N52 grade). The permanent magnet array 21 is arranged according to an array rule: every five adjacent magnets form a group, with the magnetization directions sequentially upward, rightward, downward, leftward, and upward, creating a magnetic field that is enhanced on the lower surface and weakened on the upper surface. The permanent magnets are preferably 8mm × 8mm × 2mm in size, and their surfaces are treated with anti-corrosion coating. A constant air gap of 300μm to 500μm is maintained between the mover and the stator to achieve contactless levitation and movement.

[0085] The stator position detection employs a combination of Hall effect sensor arrays and optical encoders. The Hall effect sensor array, distributed 30mm apart on the stator surface, is used for coarse positioning and levitation control. The optical encoder achieves precise positioning. The control system adopts a feedforward-feedback hybrid control strategy. The feedback loop uses PID control, while the feedforward loop incorporates compensation based on a dynamic model to effectively suppress nonlinear disturbances, achieving a positioning accuracy within 2μm. Considering factors such as temperature drift and electromagnetic interference, the system is designed with a temperature compensation algorithm and an anti-interference filter.

[0086] like Figure 3 As shown, the wireless charging system includes a radio transmitting coil 3 disposed in a specific area of ​​the stator and a radio receiving coil 4 integrated into the mover.

[0087] The transmitting coil 3 is embedded in a specific area of ​​the ferrite core 31 of the stator 1, electromagnetically isolated from the surrounding stator coils 11, and employs a resonant structure. The transmitting coil 3 has a diameter of 150mm, 20 turns, and operates at a frequency of 85kHz. The high-frequency inverter adopts a full-bridge topology, using SiC MOSFETs or IGBTs as power devices to improve switching efficiency. The resonant circuit uses an LCC or LLC compensation network to optimize electromagnetic coupling efficiency.

[0088] The receiving coil 4 is integrated on the ferrite core 41 at the bottom of the mover 2. It adopts a planar spiral shape with an outer diameter of 100mm and 15 turns, and is electromagnetically compatible with the permanent magnet array 21. The rectifier circuit uses synchronous rectification technology. The charging management chip supports constant current charging, constant voltage charging, and trickle charging modes, and automatically switches according to the battery status.

[0089] The wireless charging system features multi-level protection, including overvoltage protection, overcurrent protection, overtemperature protection, and foreign object detection. Foreign object detection is achieved by monitoring changes in the transmitting coil current; when a metallic foreign object is detected, the system automatically reduces power or stops charging.

[0090] like Figure 1 As shown, the self-powered lifting mechanism includes a lifting device 6 integrated on the actuator, a battery pack 5, a linear motor 8, and a wafer clamping device 7.

[0091] Battery pack 5 consists of 8 to 12 lithium batteries connected in series and parallel, with a rated voltage of 18V to 36V and a rated capacity of 3000mAh.

[0092] The battery management system features equalization charging, overcharge and over-discharge protection, temperature monitoring, and lifespan prediction. The system includes a battery status monitoring circuit that monitors battery voltage, current, and temperature in real time to ensure the battery operates within safe limits. The battery compartment is equipped with a thermal management system to maintain the battery temperature within its operating range.

[0093] The lifting device 6 employs a three-rail support structure to ensure balanced load and stable movement. The rails are made of high-precision materials, such as alumina ceramic or precision steel. Precision ball bearings or air bearings are used between the rails and the slider to achieve low-friction movement.

[0094] The drive system employs a linear motor (8-speed), which may have a coreless or iron-core structure to eliminate or reduce motion fluctuations caused by cogging effect. The motor driver utilizes DSP or FPGA-based digital control technology, supporting sinusoidal wave drive and vector control. The lifting stroke is 200mm.

[0095] The wafer clamping device 7 employs an edge clamping method, using mechanical grippers to hold the wafer edge. The clamping system avoids contact with the wafer surface, minimizing the risk of particle contamination.

[0096] The gripper system comprises three evenly distributed gripper units, each consisting of a gripper body, a drive mechanism, and a position adjustment mechanism. The gripper body features a lightweight design, using titanium or aluminum alloy with an anodized surface. The gripper contact surfaces are covered with a 1mm thick soft material such as PEEK or PTFE to prevent damage to the wafer edges.

[0097] The hydraulic component of the gripper drive mechanism generates hydraulic pressure through a hydraulic cylinder. This pressure is distributed to the liquid guide grooves of each gripper finger through a distribution box. The hydraulic pressure is transmitted to each gripper finger through the liquid guide grooves, causing the internal chamber of the gripper finger to expand and deform, thereby achieving the gripping of the wafer and ensuring stable gripping without damaging the wafer.

[0098] The layout flexibility of wireless magnetic levitation wafer handling devices is as follows: Figure 4 As shown, traditional robotic arm wafer handling devices 91 are limited by joint kinematics, restricting wafer cassettes to a fixed circular or fan-shaped area. The wireless magnetic levitation wafer handling device 92 overcomes this limitation, achieving full coverage of the entire stator plane, and allowing for flexible adjustment of the wafer cassette layout according to process requirements. With the same floor space, the wireless magnetic levitation wafer handling device 92 offers a larger effective working area and higher space utilization.

[0099] Example 2

[0100] This embodiment provides a cluster control scheme for multi-device collaborative operation, such as... Figure 5 As shown.

[0101] Multiple magnetic levitation transport devices 92 are interconnected via wireless networks (WiFi, ZigBee, or LoRa), employing a distributed architecture. The central scheduling system dynamically allocates transport tasks based on production plans and the status of each device, optimizing overall efficiency.

[0102] The system employs a collision avoidance algorithm based on TDMA (Time Division Multiple Access) to allocate time slots and motion channels to each device. A global coordinate system is established to track the position of each device in real time, plan the optimal motion path, and reduce waiting time.

[0103] The charging area is optimized based on the number of devices (2-8 units) and the distribution of the work area to ensure that the devices can find an available charging area within the shortest distance. The system intelligently schedules the charging sequence based on the device's battery status and task priority.

[0104] The cluster control system has a task reassignment function, which can transfer the task to other available devices within 10 to 30 seconds when a device malfunctions or runs out of power. The system also supports collaborative handling between devices, and multiple devices can be scheduled to work together to complete special tasks.

[0105] Example 3

[0106] This embodiment details the specific implementation process of a wafer handling method based on a magnetically levitated planar motor. For example... Figure 6 As shown, it includes the following steps:

[0107] (1) System initialization phase, such as Figure 7As shown, it includes parameter loading and verification, device status detection, and work area safety checks.

[0108] Parameter loading and verification. After system startup, the controller loads wafer specification parameters, process flow data, and verification environment parameters from memory.

[0109] Equipment status monitoring. Mover position calibration: The initial position of the mover is detected by a Hall sensor array, and precise calibration is performed using an optical encoder; Air gap distance detection: Confirm that the air gap between the mover and stator is maintained within the range of 400μm±50μm; Battery power detection: Read data from the battery management system, including current power level, remaining capacity, and estimated working time; When the power level is below 40%, it is marked as needing charging.

[0110] Work area safety inspection. Optical sensors scan the work area to detect foreign objects or obstacles; wafer cell position confirmation: the coordinates of the wafer cells are identified through a vision system; lifting mechanism self-test: a lifting action test is performed to confirm that the mechanical system is functioning normally.

[0111] (2) Wafer gripping stage, such as Figure 8 As shown.

[0112] Proximity Positioning: The mover moves to the vicinity of the wafer cassette in high-speed or energy-saving mode, maintaining a safe distance from the edge of the wafer cassette at the set initial moving speed; then switches to high-precision mode for final positioning at the set speed, using optical encoder feedback; Attitude Adjustment: The attitude of the mover is adjusted through the six degrees of freedom control of the magnetic levitation system to ensure that the wafer clamping device is parallel to the target wafer.

[0113] Vertical alignment: The lifting mechanism is activated and descends to a position 5mm above the target wafer; the vision system monitors the wafer center position in real time and calculates the deviation through image processing algorithms; the mover performs XY plane fine adjustment to correct the position deviation to the set range; the lifting mechanism continues to descend to 2mm above the wafer and switches to low-speed mode.

[0114] Clamping execution: The three gripper units of the wafer clamping device unfold synchronously, with an evenly distributed 120° unfolding angle; the grippers slowly approach the edge of the wafer at an initial set speed, and the force sensor monitors the contact force in real time; Initial contact detection: When the force sensor detects the contact force, the grippers stop moving; Clamping force adjustment: Based on the wafer weight and material, ensure stable clamping without damaging the wafer; Clamping status confirmation: Through dual confirmation by force sensor and optical sensor, the clamping force is stable and the wafer does not slip.

[0115] (3) Wafer handling stage, such as Figure 9 As shown.

[0116] Safety Enhancement: After clamping confirmation, the lifting mechanism rises to a safe height at the initial set speed; the attitude monitoring system is activated, using accelerometers and gyroscopes to monitor the wafer tilt angle and vibration amplitude; the clamping force is continuously monitored during the ascent to ensure it remains within the set range.

[0117] Path planning and execution: The control system calculates the optimal transport path based on the coordinates of the starting point and the destination, avoiding other equipment and obstacles.

[0118] Real-time monitoring and adjustment: During the handling process, the attitude monitoring system samples the wafer status; Vibration suppression: When the vibration amplitude is detected to exceed the set value, the moving speed is automatically reduced by 30%; Tilt correction: When the tilt angle exceeds the set value, the magnetic levitation system automatically adjusts the attitude of the mover; Environmental monitoring: Continuously monitors the status of surrounding equipment, and automatically adjusts the path or suspends movement when a conflict risk is detected.

[0119] (4) Wafer release stage, such as Figure 10 As shown.

[0120] Precise positioning: The mover moves above the target position and switches to high-precision mode; precise positioning in the XY direction is achieved through an optical encoder and vision system; attitude fine-tuning: ensures that the wafer is parallel to the target position.

[0121] Slow descent: The lifting mechanism descends slowly, approaching the target placement position; when it is 1mm away from the target surface, the speed drops to the set value; the contact detection sensor confirms that the bottom of the wafer is in contact with the target surface.

[0122] Release confirmation: After detecting stable wafer contact, the grippers gradually reduce the clamping force; the grippers slowly open at a set speed, disengaging from the wafer edge; the optical sensor confirms that the wafer has been correctly placed; the device disengages from the wafer area.

[0123] Example 4

[0124] This embodiment describes the detailed design of the intelligent control system.

[0125] The intelligent control system adopts a layered architecture, including a device layer, a control layer, and a scheduling layer. The device layer includes the drivers and sensor interfaces for each actuator, employing a distributed control structure. The control layer includes a motion planning module, a force control module, and a status monitoring module. The scheduling layer includes a task management module, a resource allocation module, and a communication interface.

[0126] Battery power management employs a predictive charging strategy. The system builds an energy consumption model based on historical data to predict the energy required for future tasks. For example... Figure 11As shown, the charging process employs an intelligent scheduling algorithm, operating during production breaks or off-peak periods. The system is configured with three levels of battery warnings: charging is prioritized when the battery level is below 40%; a warning is issued when the level is below 25%; and the charging procedure is forcibly executed when the level is below 15%.

[0127] Control of the charging process:

[0128] (1) The mover moves to the charging area;

[0129] (2) Start the wireless charging system at a frequency of 85kHz and an initial power of 30W;

[0130] (3) Charging management: including constant current charging stage, constant voltage charging stage, and trickle charging stage;

[0131] (4) Charging time: Fast charging mode reaches 80% in 45 minutes, and full charge takes 75 minutes;

[0132] (5) Once charging is complete, the system will automatically return to standby mode or continue to perform queuing tasks.

[0133] The system switches between different working modes according to work requirements:

[0134] High-precision mode: The moving part plane speed is controlled within the range of 0.005m / s ~ 0.05m / s, which improves the feedback control gain and improves the position accuracy.

[0135] High-speed mode: The planar motion speed is controlled within the range of 0.5m / s to 2.0m / s, and the shortest path algorithm is used to optimize efficiency.

[0136] Energy-saving mode: Reduces the controller refresh rate, puts some sensors into sleep mode, and adjusts the magnetic levitation system to low power consumption parameters.

[0137] Emergency handling mode: When an anomaly is detected, immediately decelerate and stop, increase the gripping force at the edge of the gripper, and send an alarm to the control center.

[0138] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A wireless magnetic levitation wafer handling device, characterized in that, include: Stator, wherein a stator coil array is disposed on the stator; The mover is positioned above the stator and maintains a preset air gap with the stator. A permanent magnet array is provided at the bottom of the mover. Non-contact levitation and planar motion are achieved through the electromagnetic interaction between the stator coil array and the permanent magnet array. A wireless charging system includes a transmitting coil disposed on the stator and a receiving coil disposed on the mover, which provides electrical energy to the mover through electromagnetic coupling. A battery module, mounted on the mover, is used to store electrical energy from the receiving coil; The lifting mechanism, powered by the battery module and mounted on the mover, is used to drive the wafer clamping device to move up and down. A wafer clamping device is mounted on the lifting mechanism and is used to clamp and release wafers.

2. The wireless magnetic levitation wafer handling device according to claim 1, characterized in that, The preset air gap between the mover and the stator is 200μm~1000μm.

3. The wireless magnetic levitation wafer handling device according to claim 1, characterized in that, The permanent magnet array is arranged in a periodic structure, with each period consisting of an odd number of permanent magnets.

4. The wireless magnetic levitation wafer handling device according to claim 3, characterized in that, The battery module includes a lithium battery pack formed by connecting 8 to 12 lithium battery cells and a battery management circuit board. The battery management circuit board is equipped with a predictive charging management algorithm, which first collects the battery pack voltage, current and temperature data in real time, and then uses the ampere-hour integral method and voltage lookup table method to accurately calculate the remaining power SOC and health status; it then builds a model based on historical energy consumption data to predict the energy consumption requirements of the task to be executed; when the power is below 15%, it triggers an emergency mode to force charging; when it is below 25%, it issues a warning and stops accepting orders after the current task ends; when it is below 40% and is during a task gap or production off-peak period, it takes advantage of the idle period to perform charging.

5. The wireless magnetic levitation wafer handling device according to claim 1, characterized in that, The stator coil array is arranged in a grid pattern, and the stator coils adopt a three-phase winding.

6. The wireless magnetic levitation wafer handling device according to claim 1, characterized in that, Both the transmitting coil and the receiving coil have a planar helical structure.

7. The wireless magnetic levitation wafer handling device according to claim 1, characterized in that, The lifting mechanism includes a vertical guide device and a lifting drive device powered by the battery module. The vertical guide device consists of a top plate, a bottom plate, and two vertical guide rails. The top plate is disposed on the vertical guide rails, and the bottom plate is disposed below the vertical guide rails. The lifting drive device includes a linear motor, a ball screw, and a lifting plate. The linear motor is disposed between the top plate and the bottom plate. The lifting plate is sleeved on the vertical guide rails through a sliding bearing. The vertical guide rails on the lifting plate move up and down. The linear motor drives the ball screw to move the lifting plate.

8. The wireless magnetic levitation wafer handling device according to claim 1, characterized in that, The wafer clamping device includes a clamping base and a clamping jaw unit. The clamping jaw unit is used to clamp the edge of the wafer. The clamping base is mounted on a lifting drive device. The clamping jaw unit is fixed on the clamping base for clamping the edge of the wafer. The clamping jaw unit includes a clamping jaw body, a hydraulic cylinder, a liquid distribution box, a liquid guiding groove, and clamping fingers. The clamping fingers are provided at the end of the clamping jaw body. The output end of the hydraulic cylinder is connected to the liquid distribution box. The output end of the liquid distribution box is connected to the clamping fingers through the liquid guiding groove.

9. The wireless magnetic levitation wafer handling device according to claim 1, characterized in that, It also includes a position detection system, which comprises an array of Hall sensors distributed on the surface of the stator and an optical encoder mounted on the mover.

10. A control method for a wireless magnetic levitation wafer handling device, characterized in that, Includes the following steps: S1: Load wafer parameters and process flow data, initialize control parameters, and detect mover position and battery status; S2: Control the mover to move to the wafer position via magnetic levitation; S3: Control the lifting mechanism to descend so that the wafer clamping device is aligned with the target wafer, and start the wafer clamping device to grab the wafer; optical sensors and force sensors monitor the grabbing status in real time; S4: Control the lifting mechanism to rise to a safe height, and control the moving part to move to the target position; S5: After the mover is precisely positioned to the target position, the lifting mechanism is controlled to descend and release the wafer, bringing the wafer close to the target position. After the correct alignment is detected, the wafer is released smoothly. S6: When the battery level is below a preset threshold, control the mover to move to the charging position for wireless charging.

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