Wafer box bidirectional synchronous transfer elevator

Abstract

This invention relates to a bidirectional synchronous conveying and lifting machine for wafer cassettes, comprising a horizontal conveying device and a rotary lifting device including a frame, two sets of conveying mechanisms, a synchronous drive shaft, a first bearing station, and a second bearing station. Each set of conveying mechanisms includes an upper pulley, a lower pulley, a first drive belt, and a second drive belt. Both the upper and lower pulleys have a double-layer wheel structure, and the first and second drive belts are wound side-by-side around the upper and lower pulleys. The upper pulleys of the two sets of conveying mechanisms are connected by a synchronous drive shaft, which is connected to the drive shaft of a servo motor. The first bearing station is fixed across the first side of the first and second drive belts of the two sets of conveying mechanisms, and the second bearing station is fixed across the second side of the first and second drive belts of the two sets of belt conveying mechanisms. A gripping mechanism includes a robotic arm and a vertical drive mechanism. This invention achieves bidirectional transport of wafer cassettes through two sets of conveying mechanisms, eliminating the need for machine downtime and resulting in high transport efficiency.

Description

Technical Field

[0001] This invention relates to the field of semiconductor automated conveying equipment technology, and in particular to a bidirectional synchronous conveying and lifting machine for wafer cassettes. Background Technology

[0002] In the semiconductor wafer manufacturing process, wafer cassettes serve as the core carriers for holding and transporting wafers. Their automated, high-precision, and high-cleanliness transport operations across floors are crucial for ensuring the continuous and stable operation of semiconductor production lines. Currently, the wafer cassette cross-floor lifting and transport equipment used in the industry is mostly a traditional single-drive, single-chain, or single-drive belt lifting structure, with a simple overall design and a single operating mode.

[0003] Existing lifting equipment generally adopts a single-end drive mode, which can only realize unidirectional lifting and conveying. It cannot complete bidirectional synchronous parallel transfer of wafer boxes between upper and lower floors. The conveying cycle interval is long and the operation efficiency is low, making it difficult to adapt to the high-throughput production needs of modern semiconductor production lines.

[0004] In addition, the existing robotic arms of conveying equipment mostly use fixed-point static alignment and gripping, which requires the wafer cassette to come to a complete stop before the picking and placing operations can be carried out. The waiting time is relatively long, which further limits the overall conveying efficiency.

[0005] Therefore, there is an urgent need to design a bidirectional synchronous high-speed conveying and lifting machine for wafer cassettes to address the shortcomings of existing technologies. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a wafer cassette bidirectional synchronous conveying and lifting machine that can realize bidirectional transport of wafer cassettes without stopping the machine and with high transport efficiency.

[0007] To solve the above technical problems, the present invention provides a bidirectional synchronous conveying and lifting machine for wafer cassettes, comprising: Horizontal conveying equipment is used to precisely transport wafer cassettes to preset transfer stations; A rotary lifting device includes a frame, two sets of conveying mechanisms opposite to each other on both sides of the frame, a synchronous drive shaft, a first bearing station, and a second bearing station. Each conveying mechanism includes an upper pulley, a lower pulley, a first drive belt, and a second drive belt. The upper and lower pulleys are both double-layer wheel structures. The first and second drive belts are wound side-by-side around the upper and lower pulleys. The upper pulleys of the two conveying mechanisms are connected by a synchronous drive shaft, which is connected to the drive shaft of a servo motor. The first bearing station is fixed across the first side of the first and second drive belts of the two conveying mechanisms, and the second bearing station is fixed across the second side of the first and second drive belts of the two belt conveying mechanisms. Both the first and second bearing stations can alternately perform upward and downward movements as the belts circulate. The gripping mechanism includes a robotic arm and a vertical drive mechanism that controls the independent lifting and lowering of the robotic arm. The lifting and lowering speed of the robotic arm is independently greater than the lifting and lowering speed of the wafer cassette, enabling dynamic high-speed alignment and gripping based on the speed difference.

[0008] In one embodiment of the present invention, the horizontal conveying device includes a conveying motor, a conveying screw, and a sliding support; the conveying motor drives the conveying screw to rotate, and the conveying screw drives the sliding support to move linearly in the horizontal direction, thereby realizing stable conveying and precise docking and positioning of the wafer cassette.

[0009] In one embodiment of the present invention, the upper pulley and the pulley are each provided with a first gear layer and a second gear layer corresponding to each other. The first gear layer meshes with the first transmission belt, and the second gear layer meshes with the second transmission belt, so as to realize the synchronous closed-loop rotation of the two sets of transmission belts.

[0010] In one embodiment of the present invention, the rotary lifting device further includes a support wheel, which is arranged along the annular path of the first transmission belt and the second transmission belt, for supporting, guiding and tensioning the two sets of transmission belts.

[0011] In one embodiment of the present invention, both the first bearing station and the second bearing station include a bearing slide and a connecting block; the bearing slide is used to support and place the wafer cassette; the connecting block is fixed to both sides of the bearing slide and rigidly connected to the corresponding transmission belt.

[0012] In one embodiment of the present invention, the vertical drive mechanism includes a support base, a lifting motor, a lifting screw, and a lifting adjustment seat. The lifting motor is mounted on the support base, and the drive shaft of the lifting motor is connected to the lifting screw. The lifting adjustment seat is slidably mounted on the lifting screw, and the main body of the robot is fixed to the lifting adjustment seat. The robot can achieve independent high-speed lifting and lowering movement through screw transmission.

[0013] In one embodiment of the present invention, linear slide rails are provided on both sides of the support base, and the lifting adjustment base is slidably connected to the linear slide rails.

[0014] In one embodiment of the present invention, the frame includes columns, beams and enclosures; the columns and beams are spliced ​​together to form a support frame, and the enclosures cover the outside of the support frame to form a sealed chamber.

[0015] In one embodiment of the present invention, a guide structure is further included, wherein the guide mechanism is fixed to the inner side of the frame to provide rigid sliding guidance for the first transmission belt and the second transmission belt.

[0016] In one embodiment of the present invention, an FFU purification component is also included. The FFU purification component is installed on the rack and is used to continuously regulate the airflow direction and cleanliness inside the equipment and isolate external dust.

[0017] Compared with the prior art, the above-described technical solution of the present invention has the following advantages: This invention discloses a bidirectional synchronous conveying and lifting machine for wafer cassettes. Through a structural design of two sets of conveying mechanisms linked by synchronous drive shafts and double-layered wheel bodies matched with double parallel drive belts, it utilizes the same closed-loop transmission to achieve synchronous bidirectional parallel transfer of the first and second bearing stations, overcoming the shortcomings of traditional equipment's unidirectional lifting and significantly improving conveying efficiency. The robotic arm is equipped with an independent vertical drive mechanism, with a lifting speed higher than the wafer cassette conveying speed. It dynamically follows and grasps based on the speed difference, eliminating stationary waiting time, shortening the work cycle, and effectively solving the bottleneck problem of wafer cassette transfer between upper and lower layers in semiconductor production lines, meeting the demands of high-cycle production. Attached Figure Description

[0018] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0019] Figure 1 This is a schematic diagram of the bidirectional synchronous conveying and lifting machine for wafer cassettes in a preferred embodiment of the present invention; Figure 2 for Figure 1 The diagram shows a top view of the bidirectional synchronous conveying elevator for wafer cassettes. Figure 3 This is a schematic diagram of the horizontal conveying device in this invention; Figure 4 This is a schematic diagram of the upper part of the rotary lifting device in this invention; Figure 5 for Figure 4 A partial structural diagram of the guide mechanism; Figure 6 This is a schematic diagram of the lower half of the rotary lifting device in this invention; Figure 7 This is a schematic diagram of the grasping structure in this invention; Explanation of reference numerals in the accompanying drawings: 1. Horizontal conveying equipment; 11. Conveyor motor; 12. Conveyor screw; 13. Sliding support seat; 2. Rotary lifting device; 21. Frame; 22. Conveying mechanism; 220. Servo motor; 221. Upper pulley; 222. Lower pulley; 223. First transmission belt; 224. Second transmission belt; 23. Synchronous transmission shaft; 24. First bearing station; 241. Bearing slide; 242. Connecting pressure block; 25. Second bearing station; 26. Support wheel; 27. Guide structure; 28. FFU purification component; 3. Gripping mechanism; 31. Robotic arm; 32. Vertical drive mechanism; 320. Support seat; 321. Lifting motor; 322. Lifting screw; 323. Lifting adjustment seat. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0021] Reference Figure 1-5 As shown, a bidirectional synchronous conveying and lifting machine for wafer cassettes according to the present invention includes: Horizontal conveyor 1 is used to accurately transport wafer boxes to a preset transfer station; A rotary lifting device 2 includes a frame 21, two sets of conveying mechanisms 22 oppositely arranged on both sides of the frame, a synchronous transmission shaft 23, a first bearing station 24, and a second bearing station 25. Each set of conveying mechanisms 22 includes an upper pulley 221, a lower pulley 222, a first transmission belt 223, and a second transmission belt 224. The upper pulley 221 and the lower pulley 222 are both double-layer wheel structures. The first transmission belt 223 and the second transmission belt 224 are wound side by side around the upper pulley 221 and the lower pulley 222. The upper pulleys of the two sets of conveying mechanisms 22... The two sets of conveyor mechanisms 22 are connected by a synchronous drive shaft 23, which is connected to the drive shaft of the servo motor 220 to realize synchronous movement of the two sets of conveyor mechanisms 22; the first bearing station 24 is fixed across the first side of the first drive belt 223 and the second drive belt 224 of the two sets of conveyor mechanisms 22, and the second bearing station 25 is fixed across the second side of the first drive belt 223 and the second drive belt 224 of the two sets of conveyor mechanisms 22; both the first bearing station 24 and the second bearing station 25 can realize the upward and downward movements alternately with the transmission belt; The gripping mechanism 3 includes a robotic arm 31 and a vertical drive mechanism 32 that controls the independent lifting and lowering of the robotic arm 31. The lifting and lowering speed of the robotic arm 31 is independently greater than the lifting and lowering speed of the wafer cassette, and it can achieve dynamic high-speed alignment gripping by relying on the speed difference.

[0022] Preferably, the horizontal conveying device 1 includes a conveying motor 11, a conveying lead screw 12, and a sliding support 13. The conveying motor 11 drives the conveying lead screw 12 to rotate, and the conveying lead screw 12 drives the sliding support 13 to move linearly in the horizontal direction, realizing stable conveying and precise docking positioning of the wafer cassette. The lead screw drive structure features high precision and high rigidity, enabling stable conveying and precise docking positioning of the wafer cassette, providing a reliable initial position reference for subsequent lifting and handling operations, and ensuring the continuity and accuracy of the entire handling process.

[0023] Furthermore, both the upper pulley 221 and the lower pulley 222 are provided with corresponding first gear layers and second gear layers. The first gear layer meshes with the first transmission belt 223, and the second gear layer meshes with the second transmission belt 224, realizing synchronous closed-loop rotation of the two sets of transmission belts. By integrating the two sets of transmission belts into the same gear train through a double-layer coaxial gear structure, the structure is compact, space utilization is high, and the gear meshing transmission accuracy is high with no slippage, ensuring the reliability of synchronous operation of the two sets of transmission belts. This facilitates flexible arrangement in space-constrained environments such as cleanrooms, reducing production line layout costs.

[0024] Furthermore, the rotary lifting device 2 also includes a support wheel 26, which is arranged along the annular path of the transmission belt to support, guide, and tension the two sets of transmission belts. The annular arrangement of the support wheel 26 effectively prevents the transmission belt from slackening, jumping, or deviating during operation, ensuring the smooth operation of the transmission belt and the positioning accuracy of the bearing station. This, in turn, ensures the stability and safety of the wafer cassette during lifting and lowering, and reduces the risk of wafer damage.

[0025] In this embodiment, both the first bearing station 24 and the second bearing station 25 include a bearing slide 241 and a connecting block 242. The bearing slide 241 is used to support and place wafer cassettes. The connecting block 242 is fixed to both sides of the bearing slide 241 and rigidly connected to the corresponding transmission belt. The first bearing station 24 and the second bearing station 25 adopt a modular design of the bearing slide 241 and the connecting block 242. The connecting block is rigidly connected to the transmission belt to ensure reliable linkage. The structure is simple, easy to assemble, disassemble and maintain, and the modular design facilitates quick replacement and adaptation according to different specifications of wafer cassettes.

[0026] like Figure 7As shown, the vertical drive mechanism 32 includes a support base 320, a lifting motor 321, a lifting screw 322, and a lifting adjustment base 323. The lifting motor 321 is mounted on the support base 320. The drive shaft of the lifting motor 321 is connected to the lifting lead screw 322, the lifting adjustment seat 323 is slidably mounted on the lifting lead screw 322, and the main body of the robot arm 31 is fixed to the lifting adjustment seat 323. Independent high-speed lifting and lowering of the robot arm is achieved through lead screw transmission. Using lead screw transmission to achieve independent high-speed lifting and lowering of the robot arm 31 provides high transmission accuracy, fast response speed, and precise control over the speed difference between the lifting speed and the rotary lifting device, ensuring the stability and reliability of dynamic high-speed positioning and grasping.

[0027] Furthermore, linear slide rails 324 are provided on both sides of the support base 320, and the lifting adjustment base 320 is slidably connected to the linear slide rails 324.

[0028] The frame 21 includes uprights, crossbeams, and side panels. The uprights and crossbeams are joined to form a support skeleton, and the side panels cover the outside of the support skeleton to form a sealed chamber. The support skeleton structure formed by the uprights and crossbeams has high strength and good stability, and the side panels can effectively prevent external dust from entering.

[0029] like Figure 6 As shown, the rotary lifting device 2 also includes a guide structure 27, which is fixed to the inner side of the frame 21 and provides rigid sliding guidance for the bearing station. Specifically, the guide structure 27 is an L-shaped guide member, which is fixedly installed on the inner side of the frame 21 and extends along the lifting direction of the transmission belt. One side of the L-shaped guide member forms a vertical guide rail surface that slides with the first transmission belt 223 and the second transmission belt 224 to achieve vertical guidance, preventing the first transmission belt 223 and the second transmission belt 224 from lateral deviation, thus simultaneously achieving the dual functions of station guidance and belt limiting.

[0030] It also includes an FFU (Fan Filter Unit) purification assembly 28, which is mounted on the rack 21 and is used to continuously regulate the airflow direction and cleanliness inside the equipment, isolating external dust. The FFU purification assembly 28 continuously regulates the airflow direction and cleanliness inside the equipment, working in conjunction with the rack to form a localized high-cleanliness environment, which can provide cleanliness assurance for wafer cassette handling, further reducing the risk of wafer contamination and meeting the requirements of high-end semiconductor manufacturing processes.

[0031] A bidirectional synchronous conveying and lifting machine for wafer cassettes based on the above structure operates on the following principle: Horizontal conveying stage: The wafer cassette to be transported is first placed on the sliding support 13 of the horizontal conveying device 1. The conveying motor 11 starts, driving the conveying screw 12 to rotate. The conveying screw 12 converts the rotational motion into the linear motion of the sliding support 13, so that the wafer cassette is smoothly transported horizontally to the preset transport station and accurately stopped and positioned. This stage provides a precise initial position reference for subsequent lifting and transport operations.

[0032] In the bidirectional synchronous lifting stage: the upper pulley 221 and the lower pulley 222 are driven to rotate synchronously by independent motors. Both the upper pulley 221 and the lower pulley 222 have a double-layer coaxial gear structure. The first gear layer meshes with the first transmission belt 223, and the second gear layer meshes with the second transmission belt 224, driving the two sets of transmission belts to rotate synchronously along a closed-loop path. The support wheels 26 arranged along the circular path of the transmission belts support, guide, and tension the transmission belts to ensure smooth operation.

[0033] The first bearing station 24 is rigidly connected to the vertically ascending sections of the first transmission belt 223 and the second transmission belt 224 via connecting pressure blocks 242 on both sides. When the transmission belts rotate, the first bearing station 24 is lifted from the lower layer to the upper layer along the vertically ascending section, completing the lifting and transport of the wafer cassette. The bearing slide 241 supports and holds the wafer cassette, and the guide structure 27 fixed inside the frame 21 provides rigid sliding guidance for the bearing slide 241 to prevent offset and swaying.

[0034] Meanwhile, the second bearing station 25 is rigidly connected to the vertical descending sections of the first transmission belt 223 and the second transmission belt 224 via its connecting pressure block 242. The second bearing station 25 descends from the upper layer to the lower layer along the vertical descending section, completing the falling and transporting of the wafer cassette.

[0035] The first bearing station 24 and the second bearing station 25 are arranged alternately along a circular path. When the upper pulley 221 and the lower pulley 222 are continuously driven synchronously, the first bearing station 24 and the second bearing station 25 run alternately in a closed loop, realizing bidirectional parallel conveying operations of lifting the lower layer of the wafer box and lowering the upper layer, which greatly improves the conveying efficiency.

[0036] Dynamic high-speed gripping stage: When the carrier station carrying the wafer cassette moves to the gripping station, the robotic arm 31 of the gripping mechanism 3 is activated. The lifting motor 321 of the vertical drive mechanism 32 drives the lifting screw 322 to rotate, causing the lifting adjustment seat 323 and the main body of the robotic arm 31 fixed thereon to perform independent high-speed lifting and lowering movements along the side mounting position of the frame. The lifting speed of the robotic arm 31 is independently greater than the lifting speed of the wafer cassette transport, and the main body of the robotic arm 31 achieves dynamic high-speed alignment by relying on this speed difference.

[0037] The main body of the robotic arm 31 completes the gripping or releasing of wafer cassettes during high-speed alignment, achieving precise gripping without waiting for the carrier station to come to a complete stop, significantly shortening the single transport cycle. After gripping, the robotic arm 31 can quickly reset or move to the next station, achieving continuous and efficient operation.

[0038] Clean environment maintenance phase: Throughout the transport process, the uprights 211 and beams 212 of the rack 21 are spliced ​​together to form a support frame, and the surrounding panels cover the outside of the support frame to form a sealed chamber, effectively isolating external dust from intrusion. The FFU purification unit 28 installed on the rack 21 continuously delivers filtered clean air into the sealed chamber, regulating the airflow direction and cleanliness inside the equipment to maintain a higher level of clean environment and ensure that the wafer cassette is free from micro-dust contamination throughout the transport process.

[0039] After completing one transport cycle, the unloaded carrier station continues to run along the closed-loop rotary path, returning to the initial station to load the next wafer cassette. The first carrier station 24 and the second carrier station 25 continuously alternate in a cycle, which, together with the continuous feeding of the horizontal conveyor 1 and the high-speed gripping of the gripping mechanism 3, forms an efficient, continuous, bidirectional parallel wafer cassette transport operation process.

[0040] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A bidirectional synchronous conveying and lifting machine for wafer cassettes, characterized in that, include: Horizontal conveying equipment is used to precisely transport wafer cassettes to preset transfer stations; A rotary lifting device includes a frame, two sets of conveying mechanisms opposite to each other on both sides of the frame, a synchronous drive shaft, a first bearing station, and a second bearing station. Each conveying mechanism includes an upper pulley, a lower pulley, a first drive belt, and a second drive belt. The upper and lower pulleys are both double-layer wheel structures. The first and second drive belts are wound side-by-side around the upper and lower pulleys. The upper pulleys of the two conveying mechanisms are connected by a synchronous drive shaft, which is connected to the drive shaft of a servo motor. The first bearing station is fixed across the first side of the first and second drive belts of the two conveying mechanisms, and the second bearing station is fixed across the second side of the first and second drive belts of the two belt conveying mechanisms. Both the first and second bearing stations can alternately perform upward and downward movements as the belts circulate. The gripping mechanism includes a robotic arm and a vertical drive mechanism that controls the independent lifting and lowering of the robotic arm. The lifting and lowering speed of the robotic arm is independently greater than the lifting and lowering speed of the wafer cassette, enabling dynamic high-speed alignment and gripping based on the speed difference.

2. The wafer cassette bidirectional synchronous conveying and lifting machine according to claim 1, characterized in that, The horizontal conveying equipment includes a conveying motor, a conveying screw, and a sliding support base; the conveying motor drives the conveying screw to rotate, and the conveying screw drives the sliding support base to move linearly in the horizontal direction, so as to realize the stable conveying and precise docking and positioning of the wafer cassette.

3. The wafer cassette bidirectional synchronous conveying and lifting machine according to claim 1, characterized in that, Both the upper pulley and the pulley are provided with corresponding first gear layers and second gear layers. The first gear layer meshes with the first transmission belt, and the second gear layer meshes with the second transmission belt, so as to realize the synchronous closed-loop rotation of the two sets of transmission belts.

4. The wafer cassette bidirectional synchronous conveying and lifting machine according to claim 1, characterized in that, The rotary lifting device also includes a support wheel, which is arranged along the annular path of the first and second transmission belts to support, guide and tension the two sets of transmission belts.

5. The wafer cassette bidirectional synchronous conveying and lifting machine according to claim 1, characterized in that, Both the first and second bearing stations include a bearing slide and a connecting block; the bearing slide is used to support and place the wafer cassette; the connecting block is fixed to both sides of the bearing slide and rigidly connected to the corresponding transmission belt.

6. The wafer cassette bidirectional synchronous conveying and lifting machine according to claim 1, characterized in that, The vertical drive mechanism includes a support base, a lifting motor, a lifting screw, and a lifting adjustment seat. The lifting motor is mounted on the support base, and the drive shaft of the lifting motor is connected to the lifting screw. The lifting adjustment seat is slidably mounted on the lifting screw, and the main body of the robot is fixed to the lifting adjustment seat. The robot can achieve independent high-speed lifting and lowering movement through screw transmission.

7. The wafer cassette bidirectional synchronous conveying and lifting machine according to claim 6, characterized in that, Linear slide rails are provided on both sides of the support base, and the lifting adjustment base is slidably connected to the linear slide rails.

8. The wafer cassette bidirectional synchronous conveying and lifting machine according to claim 1, characterized in that, The frame includes columns, beams, and enclosure panels; the columns and beams are spliced ​​together to form a support frame, and the enclosure panels cover the outside of the support frame to form a sealed chamber for isolating external dust.

9. The wafer cassette bidirectional synchronous conveying and lifting machine according to claim 8, characterized in that, It also includes a guide structure, which is fixed inside the frame to provide rigid sliding guidance for the first and second transmission belts.

10. The wafer cassette bidirectional synchronous conveying and lifting machine according to claim 8, characterized in that, It also includes an FFU purification component, which is installed on the rack and is used to continuously regulate the airflow direction and cleanliness inside the equipment to isolate external dust.

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