Wafer rewinding machine

Abstract

The invention relates to a wafer rewinding machine which comprises a machine case, a control system, a material box positioning module, a robot carrying module and a centering calibration module are arranged on the machine case, the material box positioning module, the robot carrying module and the centering calibration module are in signal connection with the control system, the material box positioning module comprises a load port and a material box turnover mechanism, and an FOUP wafer material box is installed in the material box turnover mechanism. A CST wafer box is arranged on one side of the case; the robot carrying module comprises a multi-axis telescopic mechanical arm and a transverse moving shaft for driving the multi-axis telescopic mechanical arm to move horizontally, one end of the multi-axis telescopic mechanical arm is installed on the horizontal transverse moving shaft, the horizontal transverse moving shaft is installed on one side of the table top of the case, and the centering and calibrating module is arranged on the table top of the case and used for centering and calibrating the position of a wafer; and the control system controls the load port to open the FOUP wafer box and scan the wafer, then controls the multi-axis telescopic mechanical arm to transfer the wafer from the FOUP wafer box to the centering calibration module, and controls the multi-axis telescopic mechanical arm to put the wafer into the CST wafer box after centering calibration.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing equipment technology, and in particular to a wafer flipping machine. Background Technology

[0002] In semiconductor manufacturing, there is a need to switch wafer pods between two processes, such as switching wafer FOUP or wafer CST pods at different process stages. This switching is usually done manually, which has the following drawbacks: low efficiency (manual wafer handling is time-consuming, affecting production line cycle time); positioning errors (manual placement can easily lead to misalignment of the pods, causing wafer breakage); and high cost (reliance on skilled workers, resulting in continuously increasing labor costs). Existing automated equipment lacks an integrated solution for pod switching, necessitating a highly efficient and precise wafer flipping device. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a wafer flipping machine, which is a device that can replace manual labor, increase the speed of wafer flipping, and reduce the occurrence of misaligned slots.

[0004] The above-mentioned objective of this invention is achieved through the following technical solutions:

[0005] A wafer flipping machine includes a chassis, on which a control system is provided, as well as a cassette positioning module, a robot handling module, and an alignment and calibration module that are signal-connected to the control system. The cassette positioning module includes a load port and a cassette flipping mechanism, in which a FOUP wafer cassette is installed. A CST wafer cassette is provided on one side of the chassis.

[0006] The robot handling module includes a multi-axis telescopic robotic arm and a horizontal axis that drives its horizontal movement. One end of the multi-axis telescopic robotic arm is mounted on the horizontal axis, which is mounted on one side of the chassis platform. The alignment and calibration module is set on the chassis platform for wafer position alignment and calibration.

[0007] The control system controls the load port to open the FOUP wafer cassette and scan the wafer, then controls the multi-axis telescopic robotic arm to transfer the wafer from the FOUP wafer cassette to the alignment and calibration module. After alignment and calibration, the control system controls the multi-axis telescopic robotic arm to place the wafer into the CST wafer cassette.

[0008] As a further technical solution of the present invention: the end of the multi-axis telescopic robotic arm is provided with a vacuum adsorption tooth fork, and the adsorption force of the vacuum adsorption tooth fork is adjustable in the range of 0-10kPa.

[0009] As a further technical solution of the present invention: the cassette flipping mechanism includes a base and a flipping frame. The base is fixed to one side of the chassis, the load port is disposed on the base, the bottom of the flipping frame is hinged to the base via a pivot, a cylinder is disposed inside the base, one end of the piston rod of the cylinder is hinged to the bottom of the flipping frame, driving the flipping frame to rotate around the pivot, the flipping frame has a horizontal placement position and an inclined loading position at a 60° angle with the horizontal plane under the drive of the cylinder, the FOUP wafer cassette is mounted on the flipping frame, and a baffle for limiting the position of the FOUP wafer cassette is fixed on one side of the flipping frame.

[0010] As a further technical solution of the present invention: a positioning component for limiting the displacement of the FOUP wafer cassette is provided on the bearing surface of the flipping frame. The positioning component includes four positioning blocks that can be detachably fixed on the flipping frame. The four positioning blocks are rectangularly distributed on the bearing surface of the flipping frame.

[0011] As a further technical solution of the present invention: clamping mechanisms for clamping the FOUP wafer cassette are symmetrically arranged on both sides of the flipping frame. The clamping mechanism includes a clamping cylinder, a telescopic plate and a pressure block. The clamping cylinder is located inside the flipping frame and one end of the piston rod of the clamping cylinder is fixedly connected to the telescopic plate. The pressure block is fixed on the inner wall of the end of the telescopic plate that extends out of the flipping frame.

[0012] As a further technical solution of the present invention: a material box in-place sensor is provided on the bearing surface of the flipping frame, and the material box in-place sensor is used to detect whether the FOUP wafer material box is installed in place;

[0013] A tab sensor is provided on one edge of the bearing surface of the flipping frame. The tab sensor is used to detect whether the wafer protrudes from the FOUP wafer cassette.

[0014] Two hydraulic buffers are provided on the base. When the tilting frame is in a horizontal position driven by the cylinder, the hydraulic buffers are in contact with the bottom of the tilting frame.

[0015] As a further technical solution of the present invention: the centering calibration module includes:

[0016] A central positioning stage, wherein the surface of the central positioning stage is provided with vacuum adsorption holes to adsorb the bottom surface of the wafer;

[0017] The left linear drive module and the right linear drive module are symmetrically arranged on both sides of the central positioning stage, and their output ends are respectively connected to the left push plate and the right push plate.

[0018] A wafer in-situ sensor is mounted on the central positioning stage and located on one side of the vacuum adsorption hole;

[0019] The working surfaces of the left pusher plate and the right pusher plate are parallel to each other, and the line connecting them is perpendicular to the wafer transport direction.

[0020] As a further technical solution of the present invention: the left push plate includes a left moving plate and two left limiting blocks respectively fixed to one side edge of the left moving plate, and the left moving plate is detachably fixed to the left linear drive module;

[0021] The right push plate includes a right moving plate and two right limiting blocks respectively fixed to one side edge of the right moving plate. The right moving plate is detachably fixed to the right linear drive module.

[0022] As a further technical solution of the present invention: the left limiting block and the right limiting block are arranged in an arc shape on the side of the wafer.

[0023] As a further technical solution of the present invention: the vacuum adsorption hole is connected to a negative pressure generator through a gas path to form a negative pressure adsorption zone;

[0024] An adsorption platform is provided on the central positioning platform, and three vacuum adsorption holes are provided. The three vacuum adsorption holes are located at the center of the adsorption platform, and adsorption grooves are provided on the adsorption platform in a ring-shaped distribution.

[0025] In summary, the present invention has at least one of the following beneficial technical effects:

[0026] 1. This invention discloses a wafer flipping machine to solve the problems of low efficiency, easy misalignment, and high breakage rate when manually switching wafer cassettes. The device includes: a cassette positioning module (including a load port and a cassette flipping mechanism) for fixing the FOUP wafer cassette; a robot handling module (including a transverse axis and a multi-axis telescopic robotic arm driven by it), with a wafer gripper (vacuum suction toothed fork) at its end; a centering calibration module, which achieves closed-loop calibration of the wafer position through the gripping mechanism and sensors; and a control system linking all modules. The workflow is as follows: after manual loading, the control system controls the robot to pick up wafers from the FOUP wafer cassette, accurately place them into the CST wafer cassette after centering calibration, and repeat the cycle until the flipping is complete. Its innovations lie in: the integrated cassette positioning and flipping mechanism enabling collaborative processing of two cassettes; the collaborative optimization of the handling path by the transverse axis and the multi-axis telescopic robotic arm; and real-time centering compensation to eliminate accumulated errors. The effects include more than 3 times improvement in wafer flipping efficiency, near-zero misalignment rate, and 90% reduction in breakage rate. It eliminates efficiency bottlenecks caused by manual operation, avoids wafer placement misalignment and slot risks, and reduces breakage rate and labor costs.

[0027] 2. The cassette flipping mechanism of the present invention includes a base, a flipping frame hinged at the bottom, a cylinder driving the flipping frame, a positioning block on the bearing surface, clamping cylinders on both sides, and a cassette position sensor and a tab sensor. The flipping frame can be rotated from a horizontal position to a 60° tilted position under the drive of the cylinder. Horizontal placement of the cassette reduces operational intensity; during flipping, the wafer automatically slides into the bottom of the cassette under gravity, avoiding the risk of slipping out; the positioning block and clamping cylinders ensure the stability of the cassette; multiple sensors ensure reliable process. It solves the problem of wafers easily slipping out during traditional flat loading, requiring manual intervention, and significantly improves safety and efficiency.

[0028] 3. The alignment and calibration module of this invention includes a central vacuum adsorption stage, symmetrically arranged left / right linear drive modules, and a wafer in-situ sensor. Through synchronous centripetal movement of the dual drive modules, the wafer is pushed to the central positioning surface, solving the center offset problem caused by traditional unilateral pushing. Its innovation lies in the dual-drive symmetrical layout, which expands the intermediate tolerance space, reduces the initial wafer placement accuracy requirements, and ensures that the center offset is controllable after alignment. Attached Figure Description

[0029] Figure 1 This is a top view of the present invention.

[0030] Figure 2 It is a side view of the present invention.

[0031] Figure 3 This is a schematic diagram of the overall structure of the material box flipping mechanism of the present invention in its unflipped state.

[0032] Figure 4 This is a schematic diagram of the overall structure of the flipping posture of the material box flipping mechanism of the present invention.

[0033] Figure 5 This is a side view of the unflipped position of the hopper flipping mechanism of the present invention.

[0034] Figure 6 This is a side view of the flipping posture of the hopper flipping mechanism of the present invention.

[0035] Figure 7 This is a schematic diagram showing the structure of the bearing surface of the flipping frame for the material box flipping mechanism of the present invention.

[0036] Figure 8 This is a schematic diagram of the overall structure of the centering calibration module of the present invention in the unaligned state.

[0037] Figure 9 This is a top view of the misaligned state of the centering calibration module of the present invention.

[0038] Figure 10 This is a schematic diagram of the overall structure of the centering calibration module of the present invention in its centering state.

[0039] Figure 11 This is a top view of the alignment state of the alignment calibration module of the present invention.

[0040] Figure 12 This is a schematic diagram of the overall structure of the alignment and calibration module of the present invention (wafer omitted).

[0041] Reference numerals: 1. Chassis; 2. Control system; 3. Material box positioning module; 4. Robot handling module; 41. Multi-axis telescopic robotic arm; 42. Lateral axis; 5. Centering and calibration module; 51. Central positioning stage; 511. Adsorption stage; 512. Adsorption tank; 52. Vacuum adsorption hole; 53. Left linear drive module; 531. Left push plate; 532. Left moving plate; 533. Left limit block; 54. Right linear drive module; 55. 1. Right push plate; 542. Right moving plate; 543. Right limit block; 55. Wafer in-situ sensor; 6. Load port; 7. Tier flipping mechanism; 71. Base; 711. Hydraulic buffer; 72. Flipping frame; 73. Cylinder; 74. Baffle; 75. Positioning block; 76. Telescopic plate; 77. Pressing block; 78. Tier in-situ sensor; 79. Protrusion sensor; 8. FOUP wafer tier; 9. CST wafer tier. Detailed Implementation

[0042] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0043] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0045] Example 1:

[0046] Reference Figure 1 and Figure 2 The present invention discloses a wafer flipping machine, including a chassis 1. The chassis 1 is provided with a control system 2 and a cassette positioning module 3, a robot handling module 4 and a centering calibration module 5 connected to the control system 2 by signal. The cassette positioning module 3 includes a load port 6 and a cassette flipping mechanism 7. A FOUP wafer cassette 8 is installed in the cassette flipping mechanism 7. A CST wafer cassette 9 is provided on one side of the chassis 1.

[0047] The robot handling module 4 includes a multi-axis telescopic robotic arm 41 and a horizontal transfer axis 42 that drives its horizontal movement. One end of the multi-axis telescopic robotic arm 41 is mounted on the horizontal transfer axis 42, which is mounted on one side of the table of the chassis 1. The alignment and calibration module 5 is set on the table of the chassis 1 for wafer position alignment and calibration.

[0048] The control system 2 controls the load port 6 to open the FOUP wafer cassette 8 and scan the wafer. Then, it controls the multi-axis telescopic robotic arm 41 to transfer the wafer from the FOUP wafer cassette 8 to the alignment and calibration module 5. After alignment and calibration, it controls the multi-axis telescopic robotic arm 41 to put the wafer into the CST wafer cassette 9.

[0049] In this embodiment, the end of the multi-axis telescopic robotic arm 41 is provided with a vacuum adsorption tooth fork, and the adsorption force of the vacuum adsorption tooth fork is adjustable in the range of 0-10 kPa.

[0050] Reference Figures 3-7 The hopper flipping mechanism 7 includes a base and a flipping frame. The base is fixed to one side of the chassis 1, and the load port 6 is set on the base. The bottom of the flipping frame 72 is hinged to the base 71 via a pivot. A cylinder 73 is installed inside the base. One end of the piston rod of the cylinder 73 is hinged to the bottom of the flipping frame 72, driving the flipping frame 72 to rotate around the pivot. Under the drive of the cylinder 73, the flipping frame 72 has a horizontal placement position and an inclined loading position at a 60° angle to the horizontal plane. The FOUP wafer hopper 8 is mounted on the flipping frame 72, and a baffle 74 is fixed on one side of the flipping frame 72 to limit the position of the FOUP wafer hopper 8.

[0051] In this embodiment, a base 71, a hinged flipping frame 72, a built-in cylinder 73 (piston rod hinged to the bottom of the flipping frame 72), a horizontal / 60° dual-station configuration, and a side baffle 74 are used. The working principle is as follows: the piston rod of the cylinder 73 extends and retracts, pushing the flipping frame 72 to rotate around its axis, achieving switching between a horizontal position (manual wafer loading) and a 60° tilt position (gravity-positioned wafers); the baffle 74 physically restricts the horizontal displacement of the wafer tray. This allows the wafers to automatically slide into the bottom of the tray using gravity in the 60° tilted state, eliminating the need for manual wafer pushing; the horizontal loading station reduces the operating height by more than 50%, reducing labor intensity; and the baffle 74 provides primary positioning to prevent tray misalignment.

[0052] The bearing surface of the flipping frame 72 is provided with a positioning component for limiting the displacement of the FOUP wafer cassette 8. The positioning component works in conjunction with the baffle 74 to constrain the displacement of the cassette in the X / Y / Z directions. This eliminates the micro-displacement of the cassette during the flipping process, improving the positioning accuracy to ±0.5mm; at the same time, it provides a precise pressing reference for the clamping component.

[0053] Reference Figure 7 The positioning assembly includes four detachable positioning blocks 75 fixed to the flip frame 72. The four positioning blocks 75 are rectangularly distributed on the bearing surface of the flip frame 72. The four-point rectangular layout forms surface contact positioning, and the position of the positioning blocks 75 can be changed / adjusted to adapt to different sized wafer cassettes. It is compatible with the installation of FOUP wafer cassettes 8 of various sizes, improving production line versatility by 40%; the detachable design reduces the cost of replacing worn parts by 70%.

[0054] The flipping frame 72 is symmetrically equipped with clamping mechanisms on both sides for clamping the FOUP wafer cassette 8. Before the flipping starts, the clamping mechanisms on both sides operate synchronously to counteract the inertial force of the flipping and prevent the risk of the cassette tipping over when flipped at 60°, improving safety by 90%; the dual-side force balance design avoids deformation of the cassette under force on one side.

[0055] Reference Figure 3 The clamping mechanism includes a clamping cylinder, a telescopic plate 76, and a pressure block 77. The clamping cylinder is located inside the tilting frame 72, and one end of the piston rod of the clamping cylinder is fixedly connected to the telescopic plate 76. The pressure block 77 is fixed to the inner wall of the end of the telescopic plate 76 that extends out of the tilting frame 72. The clamping mechanism = concealed cylinder 73 + telescopic plate 76 + end pressure block 77; its working principle is as follows: the cylinder 73 is built into the tilting frame 72, the piston rod pushes the telescopic plate 76 to extend laterally, and the end pressure block 77 vertically contacts the side wall of the material box. The pressure block 77 applies vertical force to prevent slippage, and the effective utilization rate of the clamping force reaches 95%; the concealed structure reduces the exposed size of the mechanism, reducing the equipment space occupied by 30%.

[0056] A foyer position sensor 78 is installed on the bearing surface of the flipping frame 72. The foyer position sensor 78 is used to detect whether the FOUP wafer foyer 8 is installed in place. The foyer position sensor 78 is added to the bearing surface to detect the contact status between the foyer and the positioning block 75. If the foyer is not in place, the locking cylinder 73 is activated to prevent the foyer from flipping without working due to human error. It is linked with the PLC to realize the fully automatic start and stop of the process.

[0057] The number of material box in-place sensors 78 is set to at least three, distributed in the bearing surface positioning area of ​​the flipping frame 72. The three-point detection detects the contact pressure value between the front / middle / rear areas of the material box and the bearing surface, identifies abnormal states such as warping and tilting of the material box, and reduces the false alarm rate to 0.1%; it provides pressure distribution data for the clamping mechanism to dynamically adjust the clamping force.

[0058] A protrusion sensor 79 is installed on one edge of the bearing surface of the flipping frame 72. The protrusion sensor 79 is used to detect whether the wafer protrudes from the FOUP wafer cassette 8. The protrusion sensor 79 is a laser probe. The laser probe scans the edge of the cassette opening and triggers an alarm when the wafer protrusion is ≥0.2mm. This prevents wafer collisions with the robotic arm, reducing the breakage rate to 0.05%; and provides real-time feedback on abnormal wafer stacking status.

[0059] Reference Figure 4 Two hydraulic buffers 711 are installed on the base 71. When the tilting frame 72 is in a horizontal position driven by the cylinder 73, the hydraulic buffers 711 contact the bottom of the tilting frame 72. With the addition of hydraulic buffers 711 to the base 71, when the tilting frame 72 returns to the horizontal position, the buffers absorb the kinetic energy of the frame, achieving flexible stopping. Impact noise is reduced from 85dB to below 65dB, improving the working environment, extending the life of the rotating shaft by 3 times, and extending the maintenance cycle from once a month to once a quarter.

[0060] In summary, the working process of the material box flipping mechanism 7 includes the following steps:

[0061] Initial state: The tilting frame 72 is in a horizontal position;

[0062] Waste box placement: The operator places the FOUP wafer waste box 8 on the positioning block 75 of the horizontal flip frame 72, and the waste box in-place sensor 78 detects the installation status.

[0063] Clamping and fixing: The clamping cylinder is activated, and the pressure block 77 clamps the two sides of the material box;

[0064] Flipping and feeding: The bottom cylinder 73 pushes the flipping frame 72 to rotate around the axis of rotation to tilt the feeding position. The wafer automatically slides down to the bottom of the material box under the action of gravity, and the protrusion sensor 79 detects whether the wafer is protruding.

[0065] Position detection: After the tilting angle sensor confirms that the tilting frame 72 has reached a tilt angle of 60°, the mechanism completes the material loading preparation;

[0066] Reset: After the material is loaded, cylinder 73 retracts, tilting frame 72 resets to the horizontal position, and clamping cylinder is released.

[0067] Compared to existing technologies, the wafer flipping mechanism 7 has the following features: Anti-slip and self-positioning: The 60° tilt design allows the wafer to automatically slide into the bottom of the wafer bin under gravity during the flipping process, completely avoiding the manual pushing step, eliminating the risk of slippage, and improving safety. Ease of operation: The horizontal placement of the wafer bin significantly reduces operating height and labor intensity, improving human-machine efficiency. Precise positioning and clamping: Multiple positioning blocks 75 ensure accurate wafer bin positioning; the clamping cylinder prevents wafer bin displacement during flipping, ensuring stability. Multiple detection guarantees: The wafer bin position sensor 78 and the tab sensor 79 form a closed-loop detection system to ensure process reliability. Simple and efficient structure: The cylinder 73-driven flipping scheme has a compact structure, reliable operation, and low maintenance costs.

[0068] The tray flipping mechanism 7 includes a base 71, a bottom-hinged flipping frame 72, a cylinder 73 driving the flipping frame 72, a positioning block 75 on the bearing surface, clamping cylinders on both sides, a tray position sensor 78, and a tab sensor 79. The flipping frame 72 can be rotated from a horizontal position to a 60° tilt position under the drive of the cylinder 73. Horizontal placement of the tray reduces operational intensity; during flipping, the wafer automatically slides into the bottom of the tray under gravity, avoiding the risk of it slipping out; the positioning block 75 and the clamping cylinders ensure tray stability; multiple sensors ensure reliable process operation. This tray flipping mechanism solves the problem of wafers easily slipping out during traditional flat loading, requiring manual intervention, significantly improving safety and efficiency.

[0069] Reference Figures 8-12 The alignment and calibration module 5 includes: a central positioning stage 51, on which a vacuum adsorption hole 52 is provided to adsorb the bottom surface of the wafer; a left linear drive module 53 and a right linear drive module 54, which are symmetrically arranged on both sides of the central positioning stage 51, and their output ends are respectively connected to a left push plate 531 and a right push plate 541; and a wafer in-situ sensor 55, which is installed on the central positioning stage 51 and located on one side of the vacuum adsorption hole 52; wherein, the working surfaces of the left push plate 531 and the right push plate 541 are parallel to each other and the line connecting them is perpendicular to the wafer transport direction.

[0070] Reference Figure 12The central positioning stage 51 is equipped with a vacuum adsorption hole 52. The left linear drive module 53 and the right linear drive module 54 are symmetrically arranged. The wafer in-situ sensor 55 is installed on the side of the adsorption hole. The working surfaces of the left push plate 531 and the right push plate 541 are collinear and perpendicular to the wafer transport direction. Its working principle is as follows: the wafer is placed on the central positioning stage 51 → the wafer in-situ sensor 55 detects its position → the vacuum adsorption hole 52 activates and fixes the wafer; the left linear drive module 53 and the right linear drive module 54 synchronously push the push plates → the working surfaces of the left push plate 531 and the right push plate 541 clamp the wafer edge in parallel → pushing the wafer to the central positioning surface. This eliminates systematic bias, and the symmetrical force applied by the dual push plates makes the wafer center coincide with the theoretical center of the positioning stage (bias ≤ 0.1mm); it expands the tolerance space, and the width of the initial placement area can be increased to the wafer diameter + 20mm (the traditional single-sided solution is only +6mm).

[0071] Both the left linear drive module 53 and the right linear drive module 54 employ precision slide cylinders, which are mounted on the central positioning stage 51. The precision slide cylinders are directly mounted on the central positioning stage 51, and their working principle is as follows: the precision slide cylinder is integrated with the positioning stage via a rigid base → eliminating assembly errors between modules → outputting linear thrust to push the push plate. This improves centering accuracy, achieving a repeatability accuracy of ±0.02mm (compared to ±0.1mm for traditional cylinders); the structure is compact, eliminating the need for additional supports and reducing displacement deviations caused by vibration.

[0072] The left push plate 531 includes a left moving plate 532 and two left limiting blocks 533 respectively fixed to one side edge of the left moving plate 532. The left moving plate 532 is detachably fixed to the left linear drive module 53. The right push plate 541 includes a right moving plate 542 and two right limiting blocks 543 respectively fixed to one side edge of the right moving plate 542. The right moving plate 542 is detachably fixed to the right linear drive module 54. Its working principle is as follows: the moving plate transmits driving force → the limiting blocks on both sides clamp the edge of the wafer; the thickness of the limiting blocks is greater than the thickness of the wafer → only the edge is subjected to force to avoid surface contact. It realizes the anti-displacement design, the double limiting blocks form a physical constraint to prevent the wafer from tipping over during pushing; it improves the convenience of maintenance, and the detachable moving plate supports quick replacement of worn parts.

[0073] The left limiting block 533 and the right limiting block 543 are arranged in an arc shape on the side closest to the wafer. Their working principle is as follows: the arc curvature matches the wafer edge (curvature radius R = wafer radius) → surface contact replaces point contact → stress is evenly distributed. This improves the breakage rate and reduces contact stress by 70% (compared to right-angle limiting blocks); the centering guidance is optimized, and the arc surface automatically corrects minor wafer deflections.

[0074] Vacuum adsorption port 52 is connected to a negative pressure generator via an air path, forming a negative pressure adsorption zone. Its working principle is as follows: negative pressure generator starts → vacuum negative pressure is generated in the adsorption port → the bottom surface of the wafer is adsorbed and fixed → ensuring no slippage during the pushing process. This improves positioning stability, with a wafer fixing force ≥5N (actual displacement <10μm); it is resistant to vibration interference and suitable for high-speed robotic arm environments (vibration frequency ≤50Hz).

[0075] Reference Figure 12 An adsorption stage 511 is provided on the central positioning stage 51, and three vacuum adsorption holes 52 are provided, which are located at the center of the adsorption stage 511. An adsorption groove 512 distributed in a ring is formed on the adsorption stage 511. Its working principle is as follows: the vacuum adsorption holes 52 provide initial positioning adsorption force, and the annular grooves expand the adsorption area and cover the non-central area of ​​the wafer. This improves adsorption uniformity, with wafer deformation <0.05mm (compared to >0.2mm in traditional single-hole solutions); it also enhances compatibility, as the annular grooves are suitable for wafers of different thicknesses (0.1-1mm).

[0076] The working surfaces of the left pusher plate 531 and the right pusher plate 541 are covered with a flexible material layer. In this embodiment, the flexible material layer is a polyurethane buffer layer, which absorbs impact energy and reduces the collision stress between the wafer and the metal pusher plate. This achieves scratch prevention, reducing the wafer surface defect rate by 90%; noise reduction and vibration damping, with contact noise ≤45dB (≥70dB for direct metal contact).

[0077] The wafer in-situ sensor 55 is a photoelectric sensor. Its working principle is as follows: the photoelectric sensor emits an infrared beam → the wafer blocks and reflects the signal → the output level signal triggers the drive module. This improves the response speed, with a detection trigger time ≤2ms.

[0078] In summary, the centering and calibration module 5 includes a central vacuum adsorption stage 511, symmetrically arranged left / right linear drive modules 54, and a wafer in-situ sensor 55. Through synchronous centripetal movement of the dual drive modules, the wafer is pushed to the central positioning surface, solving the center offset problem caused by traditional unilateral pushing. Its innovation lies in the dual-drive symmetrical layout, which expands the intermediate tolerance space, reduces the initial wafer placement accuracy requirements, and ensures that the center offset is controllable after centering.

[0079] The implementation principle of this invention is as follows: This invention discloses a wafer flipping machine to solve the problems of low efficiency, easy misalignment, and high breakage rate when manually switching wafer cassettes. The equipment includes: a cassette positioning module 3 (including a load port 6 and a cassette flipping mechanism 7) for fixing the FOUP wafer cassette 8; a robot handling module 4 (including a transverse axis 42 and its driven multi-axis telescopic robotic arm 41), with a wafer gripper (vacuum suction toothed fork) at its end; a centering calibration module 5, which achieves closed-loop calibration of the wafer position through the gripping mechanism and sensors; and a control system 2 that links all modules. The workflow is as follows: After manual loading, the control system 2 controls the robot to pick up the wafer from the FOUP wafer cassette 8, accurately place it into the CST wafer cassette 9 after centering calibration, and repeat the cycle until the flipping is complete. Its innovations lie in: the integrated cassette positioning and cassette flipping mechanism 7 achieving collaborative processing of two cassettes; the transverse axis 42 and the multi-axis telescopic robotic arm 41 collaboratively optimizing the handling path; and real-time centering compensation eliminating accumulated errors. The effects include more than 3 times improvement in wafer flipping efficiency, near-zero misalignment rate, and 90% reduction in breakage rate. It eliminates efficiency bottlenecks caused by manual operation, avoids wafer placement misalignment and slot risks, and reduces breakage rate and labor costs.

[0080] The wafer flipping machine of this invention has significant inventiveness, mainly reflected in the following three aspects, all of which bring clear technical benefits:

[0081] An integrated wafer tray positioning and flipping mechanism enables safe and efficient wafer loading: In existing technologies, FOUP wafer trays are typically placed horizontally. During manual loading, wafers are prone to slipping out of the tray due to vibration or improper operation, requiring frequent intervention, resulting in low efficiency and a risk of breakage. This invention innovatively designs a wafer tray flipping mechanism, using a cylinder to drive the flipping frame to switch between a horizontal position and a 60° tilt position. The horizontal position facilitates manual placement of the wafer tray, reducing operating height and labor intensity; when flipped to the tilt position, the wafer automatically slides to the bottom of the tray under gravity, completely avoiding the risk of wafer protrusion or slippage. Combined with a wafer tray position sensor, a tab sensor, and a hydraulic buffer, it achieves full-process detection and flexible buffering, ensuring the safety and stability of the loading process. This structure increases wafer flipping efficiency by more than 3 times and reduces the breakage rate by 90%, significantly outperforming traditional manual or single-station equipment.

[0082] A dual-drive symmetrical alignment and calibration module achieves high-precision positioning: Traditional alignment mechanisms often use a single-sided pushing method, which easily leads to wafer center offset, low positioning accuracy, and mechanical stress damage. This invention proposes a symmetrically arranged left / right linear drive module that drives the left / right push plates to move synchronously towards the center. Combined with an arc-shaped limiting block and a vacuum adsorption stage, it achieves non-destructive clamping and center alignment of the wafer. The arc-shaped limiting block matches the wafer curvature, changing point contact to surface contact, resulting in uniform stress distribution. The vacuum adsorption holes and annular adsorption grooves work together to provide a large and uniform adsorption area, preventing the wafer from sliding or deforming during the pushing process. This structure controls the wafer center offset to ≤0.1mm and achieves a repeatability accuracy of ±0.02mm, effectively solving the offset and breakage problems caused by traditional single-sided pushing.

[0083] Multi-module collaborative control robot handling system optimizes path and compensates for errors: Existing wafer fracturing equipment often suffers from problems such as independent operation of each module, lack of coordination, and large cumulative errors. This invention integrates three major modules—material box positioning, robot handling, and centering calibration—into a closed-loop control process. A multi-axis telescopic robotic arm, driven by the lateral axis, achieves wide coverage and precise operation. The end-effector vacuum suction fork has adjustable suction force (0–10 kPa) to adapt to different wafer thicknesses and surface conditions. After the robot picks up the wafer, it undergoes real-time calibration by the centering module and is then precisely placed into the CST material box. The entire process is automated, requiring no manual intervention. This system achieves optimized wafer fracturing path and real-time error compensation, with a misalignment rate approaching zero, significantly improving equipment versatility and production cycle time.

[0084] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A wafer flipping machine, comprising a chassis (1), characterized in that, The chassis (1) is equipped with a control system (2) and a hopper positioning module (3), a robot handling module (4) and a centering calibration module (5) connected to the control system (2). The hopper positioning module (3) includes a load port (6) and a hopper flipping mechanism (7). The hopper flipping mechanism (7) is equipped with a FOUP wafer hopper (8). A CST wafer hopper (9) is provided on one side of the chassis (1). The robot handling module (4) includes a multi-axis telescopic robotic arm (41) and a horizontal axis (42) for driving its horizontal movement. One end of the multi-axis telescopic robotic arm (41) is mounted on the horizontal axis (42), which is mounted on one side of the table of the chassis (1). The alignment and calibration module (5) is set on the table of the chassis (1) for wafer position alignment and calibration. The control system (2) controls the load port (6) to open the FOUP wafer cassette (8) and scan the wafer, and then controls the multi-axis telescopic robotic arm (41) to transfer the wafer from the FOUP wafer cassette (8) to the alignment and calibration module (5). After alignment and calibration, the control system (2) controls the multi-axis telescopic robotic arm (41) to put the wafer into the CST wafer cassette (9).

2. The wafer flipping machine according to claim 1, characterized in that, The end of the multi-axis telescopic robotic arm (41) is provided with a vacuum adsorption tooth fork, and the adsorption force of the vacuum adsorption tooth fork is adjustable in the range of 0-10 kPa.

3. A wafer flipping machine according to claim 1, characterized in that, The cassette flipping mechanism (7) includes a base (71) and a flipping frame (72). The base (71) is fixed to one side of the chassis (1). The load port (6) is located on the base (71). The bottom of the flipping frame (72) is hinged to the base (71) via a pivot. A cylinder (73) is provided inside the base. One end of the piston rod of the cylinder (73) is hinged to the bottom of the flipping frame (72) to drive the flipping frame (72) to rotate around the pivot. The flipping frame (72) has a horizontal placement position and an inclined loading position at a 60° angle to the horizontal plane under the drive of the cylinder (73). The FOUP wafer cassette (8) is installed on the flipping frame (72). A baffle (74) for limiting the position of the FOUP wafer cassette (8) is fixed on one side of the flipping frame (72).

4. A wafer flipping machine according to claim 3, characterized in that, The bearing surface of the flipping frame (72) is provided with a positioning component for limiting the displacement of the FOUP wafer cassette (8). The positioning component includes four positioning blocks (75) that are detachably fixed on the flipping frame (72). The four positioning blocks (75) are rectangularly distributed on the bearing surface of the flipping frame (72).

5. A wafer flipping machine according to claim 3, characterized in that, The flipping frame (72) is symmetrically provided with clamping mechanisms for clamping the FOUP wafer cassette (8) on both sides. The clamping mechanism includes a clamping cylinder (73), a telescopic plate (76), and a pressure block (77). The clamping cylinder (73) is located inside the flipping frame (72), and one end of the piston rod of the clamping cylinder (73) is fixedly connected to the telescopic plate (76). The pressure block (77) is fixed on the inner wall of the end of the telescopic plate (76) that extends out of the flipping frame (72).

6. A wafer flipping machine according to claim 3, characterized in that, A foyer in-place sensor (78) is provided on the bearing surface of the flipping frame (72). The foyer in-place sensor (78) is used to detect whether the FOUP wafer foyer (8) is installed in place. A tab sensor (79) is provided on one side edge of the bearing surface of the flipping frame (72). The tab sensor (79) is used to detect whether the wafer protrudes from the FOUP wafer cassette (8). Two hydraulic buffers (711) are provided on the base (71). When the tilting frame (72) is in a horizontal position driven by the cylinder (73), the hydraulic buffers (711) are in contact with the bottom of the tilting frame (72).

7. A wafer flipping machine according to claim 1, characterized in that, The centering calibration module (5) includes: A central positioning stage (51) is provided with vacuum adsorption holes (52) on its surface to adsorb the bottom surface of the wafer. The left linear drive module (53) and the right linear drive module (54) are symmetrically arranged on both sides of the central positioning stage (51), and their output ends are respectively connected to the left push plate (531) and the right push plate (541). A wafer in-situ sensor (55) is mounted on the central positioning stage (51) and located on one side of the vacuum adsorption hole (52); The working surfaces of the left push plate (531) and the right push plate (541) are parallel to each other, and the line connecting the two is perpendicular to the wafer transport direction.

8. A wafer flipping machine according to claim 7, characterized in that, The left push plate (531) includes a left moving plate (532) and two left limiting blocks (533) respectively fixed on one side edge of the left moving plate (532). The left moving plate (532) is detachably fixed on the left linear drive module (53). The right push plate (541) includes a right moving plate (542) and two right limiting blocks (543) respectively fixed on one side edge of the right moving plate (542). The right moving plate (542) is detachably fixed on the right linear drive module (54).

9. A wafer flipping machine according to claim 8, characterized in that, The left limiting block (533) and the right limiting block (543) are arranged in an arc shape on the side of the wafer closest to the wafer.

10. A wafer flipping machine according to claim 7, characterized in that, The vacuum adsorption hole (52) is connected to the negative pressure generator through the gas path to form a negative pressure adsorption zone; The central positioning platform (51) is provided with an adsorption platform (511), and three vacuum adsorption holes (52) are provided. The three vacuum adsorption holes (52) are located at the center of the adsorption platform (511), and the adsorption platform (511) is provided with an adsorption groove (512) distributed in a ring.

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