A wafer processing system and a wafer processing method

Abstract

The present invention discloses a wafer processing system and a wafer processing method. The wafer processing system includes a wafer storage unit, a character recognition device, and a second handling device for transporting a wafer cassette between the wafer storage unit and the character recognition device. The character recognition device includes a loading and unloading platform for placing the wafer cassette, a calibration unit for calibrating the notch of the wafer, an OCR recognition unit for recognizing the characters of the wafer, and a first handling device for handling the wafer. A sensing and detecting member for sensing whether a wafer is placed on each accommodation groove in the wafer cassette is provided on the first handling device; a first camera for recognizing the position of the wafer cassette is provided on the second handling device. The present invention can achieve intelligent unmanned processing, improve the production efficiency of wafers, and improve the processing quality of wafers. Each handling device can automatically identify materials, and an anti-collision system is mounted on the handling device, thereby ensuring the stability of material handling.

Description

Technical Field

[0001] The present invention belongs to the technical field of wafer processing, and particularly relates to a wafer processing system and a wafer processing method. Background Art

[0002] In the wafer production stage, it is necessary to read the OCR characters on the wafer surface to know the character numbers on each wafer. Therefore, when the wafers are received, OCR character recognition is performed on each wafer and transmitted to the storage system for subsequent traceability. When the wafers are received, several wafers are stored in a wafer cassette at the same time, and several wafer cassettes are stored on a storage rack. When it is necessary to perform character recognition on the wafers, a single wafer cassette needs to be transported to the recognition device, and a single wafer is taken out from the wafer cassette each time for character recognition. After the character recognition of all the wafers in a single wafer cassette is completed, the wafer cassette is transported back to the storage rack for storage and waiting for subsequent processing.

[0003] However, with the development of industrialization, the demand for wafers has increased rapidly, the storage capacity of wafer cassettes is very large, and the length, width, and height dimensions of the storage rack are very large. Manual operation is not only difficult, but also has disadvantages such as slow speed, low efficiency, and high error rate. Although there are automated recognition devices in the prior art, for example, a wafer character OCR recognition device disclosed in Chinese Patent Publication No. CN119181659A adjusts the center and notch of the wafer to keep the wafer characters in a certain position, and then the OCR recognition unit recognizes the wafer characters. However, this recognition device mainly focuses on how to adjust the center and notch of the wafer to keep the wafer characters in a certain position and how the OCR recognition unit recognizes the wafer characters, without specifically explaining how to efficiently transport a large number of wafers and wafer cassettes. With the rapid development of the semiconductor industry, in order to improve the production efficiency and quality of wafers, it is urgent to build an intelligent unmanned processing system. The intelligent unmanned processing system needs to solve problems such as automatically recognizing and sensing items, and preventing collisions between the manipulator and other components, so that it can automatically identify the products to be transported during handling, automatically perform deviation correction actions, and prevent collisions with other materials during handling.

[0004] Therefore, it is necessary to provide a wafer processing system and a wafer processing method to solve the above technical problems. Summary of the Invention

[0005] The main object of the present invention is to provide a wafer processing system, which can realize intelligent unmanned processing, improve the production efficiency of wafers, and also improve the processing quality of wafers. Each handling device can automatically identify materials, and a collision prevention system is mounted on the handling device, thereby ensuring the stability of material handling.

[0006] The present invention achieves the above object through the following technical solutions: A wafer processing system, which includes:

[0007] A wafer storage unit, which stores a plurality of wafer cassettes, and a plurality of accommodating grooves for placing wafers are provided in the wafer cassettes;

[0008] A character recognition device, which includes a loading and unloading platform for placing the wafer cassette, a calibration unit for calibrating the notch of the wafer, an OCR recognition unit for recognizing the characters of the wafer, and a first handling device for handling the wafer. A sensing detection part for sensing whether a wafer is placed on each layer of the accommodating groove in the wafer cassette is provided on the first handling device;

[0009] A second handling device, which transports the wafer cassette between the wafer storage unit and the character recognition device. A first camera for recognizing the position of the wafer cassette is provided on the second handling device;

[0010] Wherein, the process of the first handling device sensing whether a wafer is placed on the accommodating groove in the wafer cassette is as follows:

[0011] Step S100: Set that when the sensing detection part senses that a wafer is placed on this layer of the accommodating groove in the wafer cassette, it is a first signal, and when the sensing detection part senses that no wafer is placed on this layer of the accommodating groove in the round box, it is a second signal;

[0012] Step S200: The first handling device moves to the side access opening of the wafer cassette. First, the sensing detection part scans upward for the first time at the first position to obtain a first set of scan signals; then the sensing detection part scans downward for the second time at the second position to obtain a second set of scan signals. The first position and the second position correspond to two different points in the circumferential direction of the wafer;

[0013] Step S300: Superimpose and compare the first set of scan signals and the second set of scan signals, and make a determination by corresponding the two scan results on the same layer of the accommodating groove. If at least one of the first signals is in the two scan results on this layer of the accommodating groove, it is determined that a wafer is placed on this layer of the accommodating groove. If both of the two scan results on this layer of the accommodating groove are the second signal, it is determined that no wafer is placed on this layer of the accommodating groove.

[0014] Further, the wafer storage unit includes a plurality of longitudinal trusses extending along the Z direction and a plurality of layers of transverse trusses arranged at intervals up and down on the longitudinal trusses. A plurality of bearing platforms for carrying the wafer cassette are arranged at intervals along the X direction on each layer of the transverse truss.

[0015] Further, a positioning structure for positioning the wafer cassette and a first sensor for detecting whether the wafer cassette is placed are provided on the bearing platform.

[0016] Further, the calibration unit includes a wafer placement table for placing a wafer, a rotation driving member for driving the wafer placement table to rotate about a vertical axis, and a contour recognition module disposed beside the wafer placement table for recognizing the contour of the wafer. A plurality of suction cups are provided on the wafer placement table.

[0017] Further, the first handling device includes a wafer handling mechanism for handling a wafer, a first moving unit for driving the wafer handling mechanism to move in a three-dimensional space, and a lifting driving module for driving the first moving unit to perform a lifting motion.

[0018] Further, the sensing and detecting member is disposed on the wafer handling mechanism, and a pair of forks for transferring the wafer are provided at the front end of the wafer handling mechanism.

[0019] Further, the second handling device includes a wafer cassette handling mechanism for handling a wafer cassette and a second moving unit for driving the wafer cassette handling mechanism to move in a three-dimensional space. The second moving unit is driven by a first lifting module to perform a lifting motion, and the first lifting module is driven by a first driving module to perform a horizontal motion.

[0020] Further, the first camera is disposed on the wafer cassette handling mechanism, and a pair of clamping portions for clamping the wafer cassette and a detecting element for detecting whether the wafer cassette is clamped on the clamping portions are provided at the front end of the wafer cassette handling mechanism.

[0021] Further, both the first moving unit and the second moving unit include a plurality of joint axes and a robotic arm driven by the joint axes to rotate about a vertical axis; each of the joint axes includes a motor, an encoder, and a torque sensor. The encoder is used to obtain the position of the motor movement, and the torque sensor is used to obtain the torque value of the motor in real time. If the torque value exceeds a set torque threshold, the operation of the first handling device or the second handling device stops and retreats a set distance from the stop position.

[0022] Another object of the present invention is to provide a wafer processing method, which can improve the production efficiency of the wafer and also improve the processing quality of the wafer.

[0023] The present invention realizes the above object through the following technical solutions: a wafer sensing method, which is completed based on the above wafer processing system, and includes the following steps:

[0024] S1. The second handling device moves to the wafer storage unit, the first camera takes a picture of the wafer cassette on the wafer storage unit to identify the position of the wafer cassette, and the second handling device automatically corrects the deviation to smoothly clamp the wafer cassette;

[0025] S2. The second handling device takes out the wafer cassette from the wafer storage unit and transports it to the loading and unloading platform of the character recognition device.

[0026] S3. The first handling device moves to the loading and unloading platform and senses whether there is a wafer placed on each layer of the accommodating slots in the wafer cassette.

[0027] S4. After the first handling device finishes sensing, it extends into the wafer cassette to take out the wafer and place it on the calibration unit.

[0028] S5. The calibration unit calibrates the notch of the wafer so that the wafer notch conforms to the expected position.

[0029] S6. The first handling device transports the calibrated wafer to the OCR recognition unit to recognize the characters on the wafer.

[0030] S7. The first handling device places the wafer with the characters recognized back into the wafer cassette.

[0031] S8. Steps S2 to S7 are repeated in sequence until all the characters on all the wafers in the entire wafer cassette are recognized.

[0032] S9. The second handling device moves to the loading and unloading platform, transports the wafer cassette containing the wafers with the characters recognized to the wafer storage unit, and moves to the next position of the wafer storage unit to take out a new wafer cassette for the next round of operation.

[0033] Compared with the prior art, the beneficial effects of a wafer processing system and a wafer processing method of the present invention are as follows:

[0034] (1) A wafer storage unit and a character recognition device are provided, which can automatically complete the taking and placing of the wafer cassette from the wafer storage unit, and complete the recognition of the wafer characters and other processing actions on the character recognition device. The entire processing process does not require manual operation, can achieve intelligent unmanned processing, can improve the production efficiency of the wafer, and at the same time, can also improve the processing quality of the wafer.

[0035] (2) A sensing detection component for sensing whether there is a wafer placed on each layer of the accommodating slots in the wafer cassette is provided on the wafer handling mechanism of the first handling device. By taking two scans to obtain a first scan signal set and a second scan signal set respectively, and superimposing and comparing the first scan signal set and the second scan signal set, it can be judged whether there is a wafer placed on the accommodating slots of the wafer cassette. It can conveniently, quickly and accurately automatically identify whether there is a wafer placed on the accommodating slots of the wafer cassette. Moreover, through the two-scan method, the problem of misjudgment caused by the notch of the wafer can be solved, and the accuracy of wafer sensing can be improved.

[0036] (3) A first camera for identifying the position of the wafer cassette is provided on the wafer cassette handling mechanism of the second handling device. When picking up the wafer cassette, the first camera takes a picture of a certain carrying platform, and will confirm whether there is a wafer cassette on the carrying platform, whether there is a wafer in the wafer cassette, and identify information such as the identification points on the wafer cassette according to the taken picture. It will also detect whether the position of the wafer cassette on the carrying platform is offset according to the position and attitude of the identification points. If the position of the wafer cassette is offset, the second moving unit drives the wafer cassette handling mechanism to move to complete the automatic alignment action, so as to adapt to the wafer cassette so that the clamping part of the wafer cassette handling mechanism can accurately clamp on both sides of the wafer cassette, which can avoid the risk of wafer contamination and breakage caused by inaccurate clamping position and the dropping of the wafer cassette, and can improve the stability during the handling of the wafer cassette.

[0037] (4) Anti-collision systems are installed on both the first handling device and the second handling device. Each of the several joint axes of the first moving unit and each of the several joint axes of the second moving unit includes a motor, an encoder, and a torque sensor. The encoder and the torque sensor are both connected to the anti-collision system. The encoder is used to obtain the position of the motor movement, and the torque sensor is used to obtain the torque value of the motor in real time. When the torque value of any one or more motors exceeds the torque threshold under the set operating scenario, the anti-collision system immediately responds and issues an alarm. At the same time, the operation of the first handling device or the second handling device stops and retreats a set distance from the stop position, which can prevent hitting other materials and also avoid the risk of the wafer cassette or wafer dropping, and can improve the stability during the handling of the materials. Description of the Drawings

[0038] Figure 1 It is a top view structural schematic diagram of the wafer processing system according to an embodiment of the present invention;

[0039] Figure 2 It is a partial structural schematic diagram of the wafer storage unit according to an embodiment of the present invention;

[0040] Figure 3 It is a three-dimensional structural schematic diagram of the character recognition device according to an embodiment of the present invention;

[0041] Figure 4 It is a three-dimensional structural schematic diagram of the calibration unit according to an embodiment of the present invention;

[0042] Figure 5 It is a three-dimensional structural schematic diagram of the first handling device according to an embodiment of the present invention;

[0043] Figure 6 It is a three-dimensional structural schematic diagram of the lifting drive module according to an embodiment of the present invention;

[0044] Figure 7 It is a structural schematic diagram of the first handling device removing the lifting drive module according to an embodiment of the present invention;

[0045] Figure 8 Schematic three-dimensional structure diagram of the second handling device according to an embodiment of the present invention;

[0046] Figure 9 Schematic structure diagram of the second moving unit and the wafer cassette handling mechanism according to an embodiment of the present invention;

[0047] The numbers in the figure indicate:

[0048] 100 - wafer processing system; 200 - wafer cassette, 300 - wafer;

[0049] 1 - wafer storage unit, 11 - longitudinal truss, 12 - transverse truss, 13 - carrier platform, 14 - positioning structure, 15 - first sensor;

[0050] 2 - second handling device, 22 - second moving unit, 221 - first mounting plate, 222 - fourth joint axis, 223 - third robotic arm, 224 - fifth joint axis, 225 - fourth robotic arm, 226 - sixth joint axis, 23 - wafer cassette handling mechanism, 231 - clamping part, 232 - detection element, 24 - first lifting module, 241 - bottom plate, 242 - second motor, 243 - first transmission shaft, 244 - mounting frame, 245 - second transmission shaft, 246 - first transmission belt, 25 - first driving module, 253 - rack, 254 - base;

[0051] 3 - character recognition device, 31 - loading and unloading platform, 32 - calibration unit, 321 - wafer placement table, 322 - rotation driving part, 323 - profile recognition module, 324 - suction cup, 33 - OCR recognition unit, 34 - first handling device, 341 - first moving unit, 3411 - first joint axis, 3412 - first robotic arm, 3413 - second joint axis, 3414 - second robotic arm, 3415 - third joint axis, 342 - lifting driving module, 3421 - first motor, 3422 - lead screw, 3423 - lifting column, 3424 - pulley assembly, 3425 - mounting housing, 3426 - slide rail, 3427 - lifting plate, 3428 - slider, 343 - wafer handling mechanism, 3431 - fork, 344 - sensing detection part, 35 - air filter. Detailed implementation manners

[0052] Embodiment 1:

[0053] Please refer to Figures 1-9 , in this embodiment, there is a wafer processing system 100, and a wafer processing system 100 includes:

[0054] A wafer storage unit 1, which stores a plurality of wafer cassettes 200, and a plurality of accommodation grooves for placing wafers 300 are provided in the wafer cassettes 200;

[0055] A character recognition device 3, which includes a loading and unloading platform 31 for placing a wafer cassette 200, a calibration unit 32 for calibrating the notch of a wafer 300, an OCR recognition unit 33 for recognizing the characters of the wafer 300, and a first transfer device 34 for transferring the wafer.

[0056] A second transfer device 2, which transfers the wafer cassette 200 between the wafer storage unit 1 and the character recognition device 3.

[0057] As Figure 2 shown, it is a partial view of the wafer storage unit 1. The wafer storage unit 1 includes a plurality of longitudinal trusses 11 extending in the Z direction and a plurality of layers of transverse trusses 12 arranged at intervals up and down on the longitudinal trusses 11. A plurality of carrying platforms 13 for carrying the wafer cassette 200 are arranged at intervals along the X direction on each layer of the transverse truss 12. A positioning structure 14 for positioning the wafer cassette 200 is provided on the carrying platform 13. The positioning structure 14 can be set as a positioning pin or a limiting block, or a combination of a positioning pin and a limiting block to realize the positioning of the wafer cassette. The positioning structure 14 is set according to the actual situation and is not limited herein. A first sensor 15 is provided on the carrying platform 13, which can detect whether a wafer cassette 200 is placed on the carrying platform 13, and can display in real time in the system which carrying platforms 13 have wafer cassettes 200 placed thereon and which carrying platforms 13 do not have wafer cassettes 200 placed thereon, and transmit this information to the second transfer device 2, so that the second transfer device 2 can transfer the wafer cassette to the corresponding carrying platform 13 according to the result displayed in real time.

[0058] In this embodiment, the loading and unloading platform 31 includes two wafer cassette placement positions, and wafer cassettes are placed on both of the two wafer cassette placement positions. When the first transfer device 34 picks up the wafer cassette on the first wafer cassette placement position, the second transfer device 2 transfers a new wafer cassette to the second wafer cassette placement position. If all the wafers in the wafer cassette on the first wafer cassette placement position are processed, the second transfer device 2 transfers the wafer cassette on the first wafer cassette placement position to the carrying platform 13 of the wafer storage unit 1, and the first transfer device 34 continues to take out the wafers in the wafer cassette on the second wafer cassette placement position. By setting two wafer cassette placement positions and alternating operations, the production efficiency can be improved. In other embodiments, the number of wafer cassette placement positions provided on the loading and unloading platform 31 is not limited and can be set according to the actual situation.

[0059] Before identifying the wafer characters, the characters need to be rotated to the same position for easy identification. Since there is a notch on the outer contour of the wafer, by adjusting the notch to the same position, correspondingly, the characters can be located at the same position, thus facilitating the identification of the characters. Therefore, the calibration unit 32 includes a wafer placement table 321 for placing the wafer, a rotation driving member 322 for driving the wafer placement table 321 to rotate around the vertical axis, and a contour recognition module 323 provided beside the wafer placement table 321 for recognizing the wafer contour. A plurality of suction cups 324 for adsorbing the wafer are provided on the wafer placement table 321. After the first transfer device 34 places the wafer on the wafer placement table 321, the suction cups 324 adsorb the wafer, which can prevent the position of the wafer from shifting when the wafer placement table 321 rotates.

[0060] The contour recognition module 323 is a prior art. Reference can be made to the wafer edge data pickup unit in a wafer character OCR recognition device disclosed in Chinese Patent Publication No. CN119181659A, and details will not be elaborated here. The OCR recognition unit 33 is provided beside the calibration unit 32, and the position of the OCR recognition unit 33 can be set according to the actual situation. The position of the OCR recognition unit 33 is not limited here. The structure and recognition principle of the OCR recognition unit 33 are prior arts, and details will not be elaborated here.

[0061] The calibration process of the calibration unit 32 and the wafer character recognition process are as follows: After the first transfer device 34 places the wafer on the wafer placement table 321, the suction cups 324 adsorb the wafer. Subsequently, the rotation driving member 322 drives the wafer placement table 321 to rotate, and the wafer placement table 321 drives the wafer to rotate circumferentially. During the rotation process of the wafer, the contour recognition module 323 completely obtains the edge contour data of the wafer until the wafer notch meets the expected position, and then the rotation driving member 322 stops working. The first transfer device 34 transfers the wafer to the OCR recognition unit 33 to recognize the characters of the wafer. After the recognition is completed, it is placed back into the wafer cassette 200. After all the wafers in the wafer cassette are recognized, the second transfer device 2 moves the wafer cassette back to the wafer storage unit 1.

[0062] The character recognition device 3 is also provided with an air filter 35 to ensure the cleanliness inside the character recognition device 3. In this embodiment, the air filter 35 is provided at the top of the character recognition device 3, which can clean the inside of the character recognition device 3 as much as possible. In other embodiments, the position of the air filter 35 can be set according to the actual situation, and the position of the air filter 35 is not limited here.

[0063] The first transfer device 34 includes a wafer transfer mechanism 343 for transferring the wafer, a first moving unit 341 for driving the wafer transfer mechanism 343 to move in three-dimensional space, and a lifting driving module 342 for driving the first moving unit 341 to perform lifting motion.

[0064] The lifting drive module 342 includes a first motor 3421, a lead screw 3422 driven by the first motor 3421 for transmission, a lifting plate 3427 disposed on the lead screw 3422, and a lifting column 3423 disposed on the lifting plate 3427. The lifting column 3423 drives the first moving unit 341 to perform a lifting motion. In order to shorten the length of the lifting drive module 342, the first motor 3421 is not directly connected to the bottom of the lead screw 3422, but is arranged parallel to the side of the lead screw 3422, and the rotation transmission between the first motor 3421 and the lead screw 3422 is realized through a belt pulley assembly 3424. An installation housing 3425 is disposed on the outer periphery of the lifting drive module 342, and the lifting drive module 342 is wrapped inside, which can avoid problems such as internal part contamination. An avoidance opening for the lifting column 3423 to move up and down is provided at the top of the installation housing 3425. The first motor 3421 is installed at the bottom of the installation housing 3425. In order to ensure the stability of the up and down movement of the lifting column 3423, a vertical slide rail 3426 is provided on the installation housing 3425, and the lifting plate 3427 is slid up and down on the slide rail 3426 through a slider 3428.

[0065] The first moving unit 341 includes a joint axis and a robotic arm driven by the joint axis to rotate around a vertical axis. In order to achieve a larger movement range and higher flexibility, a plurality of joint axes and a plurality of robotic arms connected in sequence are provided. In this embodiment, the first moving unit 341 includes a first joint axis 3411, a first robotic arm 3412 disposed at one end of the first joint axis 3411 and driven by the first joint axis 3411 to rotate around the vertical axis, a second joint axis 3413 disposed at the other end of the first robotic arm 3412 and above the first joint axis 3411, a second robotic arm 3414 disposed at one end of the second joint axis 3413 and driven by the second joint axis 3413 to rotate around the vertical axis, and a third joint axis 3415 disposed at the other end of the second robotic arm 3414 and above the second joint axis 3413. The first joint axis 3411 is connected to the top end of the lifting column 3423, and the lifting column 3423 drives the first moving unit 341 to perform a lifting motion. The wafer handling mechanism 343 is disposed on the third joint axis 3415, and the first moving unit 341 drives the wafer handling mechanism 343 to move. Compared with traditional industrial robots, the structure of the multi-stage robotic arm has a lower cost, and the larger number of joint axes means a larger movement range and higher flexibility. It can complete complex handling, sorting and other actions, can move flexibly in three-dimensional space, reach more positions and angles, and adapt to various complex working scenarios. In this embodiment, the setting of three joint axes and two robotic arms can meet the requirements of the movement range. In other embodiments, the number of joint axes and robotic arms can be set according to the actual situation, and no limitation is made here.

[0066] A pair of wafer forks 3431 for transferring wafers are provided at the front end of the wafer handling mechanism 343. The wafer forks 3431 support the bottom of the wafer and are used to pick and place wafers. A plurality of layers of accommodating grooves are provided in the wafer cassette 200, and one wafer is placed in each layer of accommodating groove. The wafer handling mechanism 343 takes out the wafers in the wafer cassette one by one for character recognition or detection, and then places the wafers back into the wafer cassette after the recognition or detection is completed. Due to various reasons, some layers in the wafer cassette do not have wafers placed. Therefore, before picking and placing the wafers, the wafer handling mechanism 343 needs to scan the positions of the wafers in the wafer cassette to sense whether there are wafers placed on each layer of accommodating groove in the wafer cassette. Therefore, a sensing and detecting member 344 is also provided on the wafer handling mechanism 343, which is used to sense whether there are wafers placed on each layer of accommodating groove in the wafer cassette 200. The sensing and detecting member 344 can be set as an optical fiber or other detecting elements, which is not limited herein. When the sensing and detecting member 344 senses whether there are wafers placed in the wafer cassette 200, it will scan each layer of the wafer cassette 200 from top to bottom or from bottom to top on the outer side of the wafer cassette, and judge whether there are wafers placed on this layer through the signal of the sensing and detecting member 344. If it is the first signal, it means that there is a wafer placed on this layer of accommodating groove. If there is a second signal, it means that there is no wafer placed on this layer of accommodating groove. However, if only scanned once, there will be a problem. Since there is a small notch on the circumferential edge of the wafer for axial positioning, when scanning the wafers in the wafer cassette, if the small notch on the wafer is scanned, it will also be displayed as the second signal, then it will be judged that there is no wafer on this layer of accommodating groove, resulting in misjudgment. To solve this technical problem, a two-scan method is adopted. First, scan from bottom to top for the first time at the first position on the outer side of the wafer cassette to obtain the first scan signal set; then scan from top to bottom for the second time at the second position on the outer side of the wafer cassette to obtain the second scan signal set. The first position and the second position correspond to two different points in the circumferential direction of the wafer; superimpose and compare the first scan signal set and the second scan signal set, and judge according to the correspondence of the two scan results of the same layer of accommodating groove. If at least one of the two scan results of this layer of accommodating groove is the first signal, it is determined that there is a wafer placed on this layer of accommodating groove. If both scan results of this layer of accommodating groove are the second signals, it is judged that there is no wafer placed on this layer of accommodating groove. By using the wafer sensing method provided by this solution, it is possible to conveniently and quickly automatically identify whether there are wafers placed on the accommodating grooves of the wafer cassette, and also accurately automatically identify whether there are wafers placed on this layer of accommodating groove.

[0067] The wafer sensing process for the sensing and detecting member 344 to sense whether there are wafers placed on the accommodating grooves in the wafer cassette 200 is as follows:

[0068] Step S100: Set that when the sensing and detecting component 344 senses that there is a wafer in this layer of the wafer cassette 200, it is the first signal, and when the sensing and detecting component 344 senses that there is no wafer in this layer of the round cassette 300, it is the second signal;

[0069] Step S200: The first handling device 34 moves to the pick-and-place opening on one side of the wafer cassette 200. First, it scans upward for the first time at the first position outside the wafer cassette to obtain the first set of scanning signals; then it scans downward for the second time at the second position outside the wafer cassette to obtain the second set of scanning signals. The first position and the second position correspond to two different points in the circumferential direction of the wafer.

[0070] Step S300: Superimpose and compare the first set of scanning signals and the second set of scanning signals, and make a determination by corresponding the two scanning results of the same layer of accommodating grooves. If at least one of the two scanning results of this layer of accommodating grooves is the first signal, it is determined that there is a wafer in this layer of the wafer cassette. If both of the two scanning results of this layer of accommodating grooves are the second signal, it is determined that there is no wafer in this layer of the wafer cassette.

[0071] The second handling device 2 includes a wafer cassette handling mechanism 23 for handling the wafer cassette and a second moving unit 22 for driving the wafer cassette handling mechanism 23 to move in three-dimensional space. The second moving unit 22 is driven by the first lifting module 24 to perform lifting motion, and the first lifting module 24 is driven by the first driving module 25 to perform horizontal motion.

[0072] The first driving module 25 provided enables the wafer cassette handling mechanism 23 to handle the wafer cassette between the wafer storage unit 1 and the character recognition device 3. In this embodiment, the first driving module 25 includes a third motor, a gear driven by the third motor to rotate, and a rack 253 engaged with the gear for transmission. The rack 253 is provided on the base 254. In other embodiments, the first driving module 25 can be set as a ground rail or other driving structures, which are not limited herein.

[0073] In this embodiment, the first lifting module 24 includes a bottom plate 241, a second motor 242 provided on the bottom plate 241, a first transmission shaft 243 driven by the second motor 242 to rotate, and a second transmission shaft 245 provided at the top of the mounting frame 244. A first transmission belt 246 is wound around the first transmission shaft 243 and the second transmission shaft 245 to achieve rotational transmission. The second moving unit 22 is provided on the first transmission belt 246, and the first transmission belt 246 drives the second moving unit 22 to perform lifting motion. Using the first transmission belt 246 to drive the second moving unit 22 to perform lifting motion can not only ensure the stability of lifting but also increase the lifting height of the second moving unit 22, enabling the pick-and-place of the wafer cassette 200 on the wafer storage unit 1 even when the height of the wafer storage unit 1 is very high.

[0074] The second moving unit 22 has the same or similar structure as the first moving unit 341. The second moving unit 22 includes a joint axis and a robotic arm driven by the joint axis to rotate around a vertical axis. In order to achieve a larger movement range and higher flexibility, a plurality of sequentially connected joint axes and a plurality of robotic arms are provided. In this embodiment, the second moving unit 22 includes a first mounting plate 221, a fourth joint axis 222 provided on the first mounting plate 221, a third robotic arm 223 having one end provided on the fourth joint axis 222 and driven by the fourth joint axis 222 to rotate around the vertical axis, a fifth joint axis 224 provided at the other end of the third robotic arm 223 and located above the fourth joint axis 222, a fourth robotic arm 225 having one end provided on the fifth joint axis 224 and driven by the fifth joint axis 224 to rotate around the vertical axis, and a sixth joint axis 226 provided at the other end of the fourth robotic arm 225 and located above the fifth joint axis 224. The wafer cassette handling mechanism 23 is provided on the sixth joint axis 226. The first mounting plate 221 is provided on the first conveyor belt 246. The first conveyor belt 246 drives the first mounting plate 221 to move up and down, thereby realizing the up and down movement of the second moving unit 22 and the wafer cassette handling mechanism 23. Compared with traditional industrial robots, the structure of the multi-stage robotic arm has a lower cost, and the larger number of joint axes means a larger movement range and higher flexibility. It can complete complex handling, sorting and other actions, can move flexibly in three-dimensional space, reach more positions and angles, and adapt to various complex working scenarios. In this embodiment, with three joint axes and two robotic arms, the requirement for the movement range can be met. In other embodiments, the number of joint axes and robotic arms can be set according to actual situations and will not be limited here.

[0075] At the front end of the wafer cassette handling mechanism 23, there are a pair of clamping parts 231 for clamping the wafer cassette and a detection element 232 for detecting whether the wafer cassette 200 is clamped on the clamping parts 231. The wafer cassette can be clamped from both sides and the bottom of the wafer cassette by the pair of clamping parts 231. The detection element 232 provided on the clamping parts 231 can detect whether the wafer cassette 200 is clamped on the clamping parts 231, and then feed the information back to the second moving unit 22, and the second moving unit 22 drives the wafer cassette 200 to move. The detection element 232 can be set as an opposed fiber optic, or set as an inductive sensor, or can also be set as other detection elements. The detection element 232 can be set according to actual situations and will not be limited here.

[0076] The wafer cassette handling mechanism 23 is provided with a first camera (not shown in the figure) for identifying the position of the wafer cassette 200, which can take pictures of the carrier platform 13 and the wafer cassette 200 on the carrier platform 13. The wafer cassette 200 is provided with identification points. When picking up the wafer cassette 200, a picture is taken of a certain carrier platform 13, and information such as whether there is a wafer cassette 200 on the carrier platform 13, whether there is a wafer 300 in the wafer cassette 200, and the identification points on the wafer cassette are confirmed according to the taken picture. Also, according to the position and attitude of the identification points, it is detected whether the position of the wafer cassette 200 on the carrier platform 13 is offset. If the position of the wafer cassette 200 is offset, the second moving unit 22 drives the wafer cassette handling mechanism 23 to complete an automatic rectification action to adapt to the wafer cassette 200 so that the clamping part 231 of the wafer cassette handling mechanism 23 can accurately clamp on both sides of the wafer cassette, which can avoid the risk of wafer 300 contamination and breakage caused by inaccurate clamping position and the dropping of the wafer cassette 200, and can improve the stability during wafer cassette handling.

[0077] When the first handling device 34 and the second handling device 2 handle materials, in order to prevent the first handling device 34 and the second handling device 2 from colliding with other materials, anti-collision systems are mounted on both the first handling device 34 and the second handling device 2. The anti-collision system is a prior art and will not be described in detail here. When the first handling device 34 and the second handling device 2 are close to other materials and may collide, the anti-collision system will respond in a timely manner and remind the staff by means of alarm or suspension of work. Correspondingly, several joint axes (the first joint axis 3411, the second joint axis 3413, and the third joint axis 3415) of the first moving unit 341 and several joint axes (the fourth joint axis 222, the fifth joint axis 224, and the sixth joint axis 226) of the second moving unit 22 each include a motor, an encoder, and a torque sensor. The encoder and the torque sensor are both connected to the anti-collision system. The position of the motor movement is obtained through the encoder, and then the speed of each motor movement is calculated; the torque sensor is used to obtain the torque value of the motor in real time. When the torque value of any one or more motors exceeds the torque threshold in the set operating scenario, the anti-collision system immediately responds and issues an alarm, and at the same time, the operation of the first handling device 34 or the second handling device 2 stops. The anti-collision control method for the second handling device 2 and the first handling device 34 includes the following steps:

[0078] Step S10: Set the operating scenarios of several first handling devices 34 and second handling devices 2 respectively, and set torque thresholds for multiple motors in each of the operating scenarios;

[0079] Step S20: When the torque value of any one or more motors exceeds the torque threshold in the set operating scenario, the anti-collision system immediately responds and issues an alarm, and at the same time, the operation of the first handling device 34 or the second handling device 2 stops;

[0080] Step S30: Determine the stop position of the first handling device 34 or the second handling device 2 based on the position of the motor movement obtained by the encoder, and retreat a set distance from this stop position relative to the material, which can avoid hitting the material or damaging the material, and at the same time can also avoid the risk of the wafer cassette 200 or the wafers falling, and can improve the stability during material handling.

[0081] When applying a wafer processing system 100 provided by this solution, under the combined action of the first driving module 25 and the first lifting module 24, the second moving unit 22 and the wafer cassette handling mechanism 23 are moved to the position of the wafer storage unit 1. The joint axis of the second moving unit 22 and the robotic arm act together to move the wafer cassette handling mechanism 23 to the loading platform 13. The first camera takes pictures of the loading platform 13 and the wafer cassette 200 on the loading platform 13, and will confirm whether there is a wafer cassette 200 on the loading platform 13, whether there is a wafer 300 in the wafer cassette 200, and identify information such as the identification points on the wafer cassette according to the taken pictures. According to the position and posture of the identification points, it is detected whether the position of the wafer cassette 200 on the loading platform 13 is offset. If the position of the wafer cassette 200 is offset, the second moving unit 22 drives the wafer cassette handling mechanism 23 to complete an automatic rectification action to adapt to the wafer cassette 200 so that the clamping part 231 of the wafer cassette handling mechanism 23 can accurately clamp on both sides of the wafer cassette. After the detection element 232 detects that the wafer cassette is clamped on the clamping part 231, the first driving module 25 and the first lifting module 24 act together to move the second moving unit 22 and the wafer cassette handling mechanism 23 to the character recognition device 3. The joint axis of the second moving unit 22 and the robotic arm act together to enable the wafer cassette handling mechanism 23 to place the wafer cassette on the loading and unloading platform 31 of the character recognition device 3. The first handling device 34 starts to work. The lifting driving module 342 drives the first moving unit 341 and the wafer handling mechanism 343 to move close to the wafer cassette 200. The first moving unit 341 drives the wafer handling mechanism 343 to be located at the bottom of the wafer cassette, and the wafer fork 3431 is located at the outer peripheral edge position of the wafer. The lifting driving module 342 drives the first moving unit 341 and the wafer handling mechanism 343 to move upward so that the sensing detection part 344 scans upward for the first time at the first position outside the wafer cassette to obtain a first set of scan signals. Then the lifting driving module 342 drives the first moving unit 341 and the wafer handling mechanism 343 to move downward so that the sensing detection part 344 scans downward for the second time at the second position outside the wafer cassette to obtain a second set of scan signals. The first set of scan signals and the second set of scan signals are superimposed and compared, and the two scan results on the same layer of accommodation grooves are judged correspondingly. If at least one first signal exists in the two scan results on this layer of accommodation grooves, it is determined that there is a wafer placed on this layer of accommodation grooves. If the two scan results on this layer of accommodation grooves are both second signals, it is determined that there is no wafer placed on this layer of accommodation grooves. According to the judgment result, when the lifting driving module 342 and the first moving unit 341 act together, the wafer fork 3431 of the wafer handling mechanism 343 extends into the bottom of the layer with wafers, and the first moving unit 341 drives the wafer handling mechanism 343 to take out the wafers. The lifting driving module 342 and the first moving unit 341 act together to place the taken-out wafers on the wafer placement table 321, and the suction cup 324 adsorbs the wafers. Subsequently,The rotation driving member 322 drives the wafer placement stage 321 to rotate. The wafer placement stage 321 drives the wafer to rotate circumferentially. During the rotation of the wafer, the contour recognition module 323 completely acquires the edge contour data of the wafer until the wafer notch conforms to the expected position. Then the rotation driving member 322 stops working. The first handling device 34 transports the wafer to the OCR recognition unit 33 to recognize the characters on the wafer. After the recognition is completed, the first handling device 34 moves to the loading and unloading platform 31 and places the wafer back into the original accommodation slot in the wafer cassette. The first handling device 34 repeats the operation of taking out the wafers in the wafer cassette and transporting them to the wafer placement stage 321 and the OCR recognition unit 33 respectively for notch calibration and character recognition operations until all the wafers in the wafer cassette are recognized. After all the wafers in a wafer cassette are recognized, the recognition of all the wafers in the wafer cassette is completed. The second handling device 2 transports the wafer cassette back to the wafer storage unit 1, takes out a new wafer cassette and transports it to the loading and unloading platform 31 of the character recognition device 3, and continues to perform the character recognition of the wafers.

[0082] In other embodiments, the wafer processing system 100 is not limited to the processing device of the character recognition device 3, and may further include a sorting device, a detection device or a testing device, which is set according to the designed processing scenario and is not limited herein.

[0083] This embodiment also provides a wafer processing method, which is completed based on a wafer processing system as described above, and includes the following steps:

[0084] S1. The second handling device 2 moves to the wafer storage unit 1. The first camera takes pictures of the wafer cassette 200 on the wafer storage unit 1 to identify the position of the wafer cassette. The second handling device 2 automatically corrects the deviation to smoothly clamp the wafer cassette.

[0085] S2. The second handling device 2 takes out the wafer cassette 200 from the wafer storage unit 1 and transports it to the loading and unloading platform 31 of the character recognition device 3.

[0086] S3. The first handling device 34 moves to the loading and unloading platform 31 and senses whether there is a wafer placed on each accommodation slot in the wafer cassette.

[0087] S4. After the first handling device 34 senses, it extends into the wafer cassette to take out the wafer and place it on the calibration unit 32.

[0088] S5. The calibration unit 32 calibrates the notch of the wafer so that the wafer notch conforms to the expected position.

[0089] S6. The first handling device 34 transports the calibrated wafer to the OCR recognition unit 33 to recognize the characters on the wafer.

[0090] S7. The first transfer device 34 places the wafer after character recognition back into the wafer cassette;

[0091] S8. Sequentially repeat steps S2 to S7 until the characters of all wafers in the entire wafer cassette are recognized;

[0092] S9. The second transfer device 2 moves to the loading and unloading platform 31, transports the wafer cassette containing the wafer after character recognition to the wafer storage unit 1, and moves to the next position of the wafer storage unit 1 to take out a new wafer cassette for the next round of operation.

[0093] The above are only some embodiments of the present invention. For those of ordinary skill in the art, without departing from the inventive concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A wafer processing system, characterized in that, It includes: A wafer storage unit that stores a number of wafer cassettes, and a number of accommodating grooves for placing wafers are provided in each wafer cassette; A character recognition device, which includes a loading and unloading platform for placing the wafer cassette, a calibration unit for calibrating the notch of the wafer, an OCR recognition unit for recognizing the characters of the wafer, and a first handling device for handling the wafer. A sensing and detecting part for sensing whether a wafer is placed in each accommodating groove in the wafer cassette is provided on the first handling device; A second handling device that transports the wafer cassette between the wafer storage unit and the character recognition device, and a first camera for recognizing the position of the wafer cassette is provided on the second handling device; Among them, the process of the first handling device sensing whether a wafer is placed in the accommodating groove in the wafer cassette is as follows: Step S100: Set that when the sensing and detecting part senses that a wafer is placed in this layer of accommodating groove in the wafer cassette, it is a first signal, and when the sensing and detecting part senses that no wafer is placed in this layer of accommodating groove in the wafer cassette, it is a second signal; Step S200: The first handling device moves to the side access opening of the wafer cassette. First, the sensing and detecting part scans upward for the first time at the first position to obtain a first set of scan signals; then the sensing and detecting part scans downward for the second time at the second position to obtain a second set of scan signals. The first position and the second position correspond to two different points in the circumferential direction of the wafer; Step S300: Superimpose and compare the first set of scan signals and the second set of scan signals, and make a determination by corresponding the two scan results on the same layer of accommodating groove. If at least one of the first signals appears in the two scan results on this layer of accommodating groove, it is determined that a wafer is placed on this layer of accommodating groove. If both of the two scan results on this layer of accommodating groove are the second signal, it is determined that no wafer is placed on this layer of accommodating groove.

2. A wafer processing system according to claim 1, characterized in that: The wafer storage unit includes a number of longitudinal trusses extending in the Z direction and a number of layers of transverse trusses arranged at intervals above and below on the longitudinal trusses. A number of bearing platforms for carrying the wafer cassette are arranged at intervals along the X direction on each layer of the transverse truss.

3. A wafer processing system according to claim 2, characterized in that: A positioning structure for positioning the wafer cassette and a first sensor for detecting whether a wafer cassette is placed are provided on the bearing platform.

4. A wafer processing system as claimed in claim 1, wherein: The calibration unit includes a wafer placement table for placing the wafer, a rotation driving part for driving the wafer placement table to rotate around the vertical axis, and a contour recognition module for recognizing the wafer contour provided beside the wafer placement table. A number of suction cups are provided on the wafer placement table.

5. A wafer processing system as claimed in claim 1, wherein: The first handling device includes a wafer handling mechanism for handling the wafer, a first moving unit for driving the wafer handling mechanism to move in three-dimensional space, and a lifting driving module for driving the first moving unit to perform lifting motion.

6. A wafer processing system as claimed in claim 5, wherein: The sensing and detecting part is provided on the wafer handling mechanism, and a pair of forks for transferring the wafer are provided at the front end of the wafer handling mechanism.

7. A wafer processing system according to claim 5, wherein: The second handling device includes a wafer cassette handling mechanism for handling a wafer cassette and a second moving unit for driving the wafer cassette handling mechanism to move in a three-dimensional space. The second moving unit is driven by a first lifting module to perform a lifting motion, and the first lifting module is driven by a first driving module to perform a horizontal motion.

8. A wafer processing system according to claim 7, characterized in that: The first camera is disposed on the wafer cassette handling mechanism. A pair of clamping portions for clamping the wafer cassette and a detection element for detecting whether the wafer cassette is clamped on the clamping portions are provided at the front end of the wafer cassette handling mechanism.

9. A wafer processing system as claimed in claim 7, wherein: Both the first moving unit and the second moving unit include a plurality of joint axes and a robotic arm driven by the joint axes to rotate around a vertical axis; each of the joint axes includes a motor, an encoder, and a torque sensor. The encoder is used to obtain the position of the motor movement, and the torque sensor is used to obtain the torque value of the motor in real time. If the torque value exceeds a set torque threshold, the operation of the first handling device or the second handling device stops and retreats a set distance from the stop position.

10. A wafer processing method, which is completed based on the wafer processing system described in any one of claims 1 to 9, characterized in that, It includes the following steps: S1. The second handling device moves to the wafer storage unit, the first camera takes a picture of the wafer cassette on the wafer storage unit to identify the position of the wafer cassette, and the second handling device automatically corrects the deviation to smoothly clamp the wafer cassette. S2. The second handling device takes out the wafer cassette from the wafer storage unit and transports it to the loading and unloading platform of the character recognition device. S3. The first handling device moves to the loading and unloading platform and senses whether wafers are placed in each accommodating groove in the wafer cassette. S4. After the first handling device senses, it extends into the wafer cassette to take out the wafers and place them on the calibration unit. S5. The calibration unit calibrates the notch of the wafer so that the wafer notch conforms to the expected position. S6. The first handling device transports the calibrated wafer to the OCR recognition unit to recognize the characters on the wafer. S7. The first handling device places the wafer with the characters recognized back into the wafer cassette. S8. Steps S2 to S7 are sequentially repeated until all the characters on all the wafers in the entire wafer cassette are recognized. S9. The second handling device moves to the loading and unloading platform, transports the wafer cassette containing the wafers with the characters recognized to the wafer storage unit, and moves to the next position of the wafer storage unit to take out a new wafer cassette for the next round of operation.

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