A clamping device system and its inspection method for wafer surface inspection

Abstract

This invention relates to a wafer surface inspection clamping device system and its inspection method. Multiple clamping devices are arranged in a ring around a worktable for clamping externally fed wafers. Each clamping device includes: a telescopic stepper motor, a base disposed on the side of the telescopic stepper motor, a push-pull rod connected to the drive end of the telescopic stepper motor, and a gripper located at the front end of the push-pull rod. The push-pull rod moves along the base for guidance. A proximity switch is installed on the base, and a limit block is fixed on the push-pull rod. The limit block has a first position, a second position, and a third position on the base. The proximity switch is installed in the clamping device, and the sensing end of the proximity switch is directly opposite the limit position when the gripper clamps the wafer. The clamping action is monitored in real time to ensure that each clamping action is accurately monitored. When the proximity switch is not triggered, the system automatically initializes the gripper and tries to clamp again, thereby effectively avoiding the problem of wafers falling due to the gripper not clamping tightly.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a clamping device system and a detection method for wafer surface inspection. Background Technology

[0002] In the semiconductor manufacturing industry, wafer surface inspection is a critical step in ensuring product quality and performance. This process involves accurately identifying any minute defects, particulate contamination, or structural anomalies that may exist on the wafer surface. These factors can have a serious impact on the functionality and reliability of the final semiconductor device. Therefore, it is extremely important to ensure that the wafer can be held safely and accurately during surface inspection.

[0003] However, traditional 8-inch surface inspection devices have significant limitations in wafer clamping. These devices typically use four sets of eight grippers controlled by stepper motors to hold the wafer in mid-air. However, in actual operation, due to insufficient positioning accuracy, occasional problems such as grippers not being in place or not clamping completely occur frequently, increasing the risk of the wafer falling accidentally. This instability not only directly threatens the safety of expensive and fragile wafers, but also seriously affects production efficiency and product quality. In addition, the existing clamping mechanism lacks an effective detection and feedback system, and cannot detect the working status of the grippers in real time, which limits its application scope and reliability. Summary of the Invention

[0004] The present invention aims to solve the problems existing in the prior art by providing a clamping device system and its detection method that can effectively prevent wafers from falling due to improper clamping and improve the operational stability of the equipment.

[0005] The technical solution adopted by this invention to solve its technical problem is as follows: This wafer surface inspection clamping device system comprises multiple clamping devices arranged in a ring around the worktable for clamping externally fed wafers. Each clamping device includes: a telescopic stepper motor, a base disposed on the side of the telescopic stepper motor, a push-pull rod connected to the drive end of the telescopic stepper motor, and a gripper located at the front end of the push-pull rod. The push-pull rod moves along the base in a guided manner.

[0006] A proximity switch is installed on the base, and a limit block is fixed on the push-pull rod. The limit block has a first position, a second position, and a third position on the base. The push-pull rod is driven by a telescopic stepper motor to move the limit block on the base along the first position, the second position, and the third position. When the push-pull rod moves the limit block to the first position, the limit block is outside the detection range of the proximity switch, and the gripper contacts the bottom wall of the wafer.

[0007] When the push-pull rod moves the limit block to the second position, the limit block triggers the proximity switch and the gripper fully clamps the wafer periphery; when the push-pull rod moves the limit block to the third position, the limit block moves away from the proximity switch and the gripper releases the wafer and resets it to the initial position.

[0008] Preferably, a positioning plate is installed at the end of the base near the gripper. The positioning plate includes a first positioning part that is vertically fixed to the end face of the base and a second positioning part that extends horizontally outward from the first positioning part along the width direction of the worktable. The proximity switch is installed at the end of the second positioning part along the length direction of the base, and the sensing end of the proximity switch is directly opposite the movement path of the limit block.

[0009] Preferably, the limiting block includes a first limiting part and a second limiting part. The first limiting part has a longitudinal sliding groove with a through hole at the bottom. The second limiting part extends radially outward from the first limiting part along the worktable and is parallel to the second positioning part. The push-pull rod has a threaded hole for mounting screws. The screws pass through the through hole, the threaded section of the bolt connects to the threaded hole, and the bolt head abuts against the sliding groove. The second limiting part is aligned with the sensing end of the proximity switch.

[0010] Preferably, the drive end of the telescopic stepper motor is provided with a connector, which includes a first connecting part and a second connecting part arranged in parallel and a third connecting part perpendicularly connecting the two. The drive end of the telescopic stepper motor is fixed to the first connecting part, the tail end of the push-pull rod is fixed to the second connecting part, the front end of the third connecting part is connected to the first connecting part, and the rear end of the third connecting part is connected to the second connecting part.

[0011] Preferably, the push-pull rod is provided with a guide rod at its tail end, a first limiting ring is connected to the front end of the guide rod, the guide rod passes through the second connecting part, and a second limiting ring is sleeved on the rear end of the guide rod. The second limiting ring is in close contact with the rear end face of the second connecting part to limit the retraction stroke of the guide rod.

[0012] Preferably, a compression spring is sleeved on the guide rod, with one end of the compression spring abutting the front end face of the second connecting part and the other end of the compression spring abutting the rear end face of the first limiting ring. The compression spring is in a pre-compressed state and is used to provide elastic clamping force to the push-pull rod.

[0013] Preferably, a pair of guide seats are provided on the base along its length, and guide holes are provided in the guide seats. A pair of guide posts are provided on the push-pull rod, and the guide posts are slidably inserted into the guide holes. The limiting block is provided in the middle of the push-pull rod and is located between the two guide posts.

[0014] Preferably, the rear end of the gripper is fixed to the front end of the push-pull rod by bolts, and the front end of the gripper is provided with a horizontal support surface and a vertical abutment surface;

[0015] When the push-pull rod moves the limiting block to the first position, the supporting surface supports the bottom surface of the wafer, and the abutting surface has a gap with the periphery of the wafer; when the push-pull rod moves the limiting block to the second position, the supporting surface supports the bottom surface of the wafer, and the abutting surface presses against the periphery of the wafer.

[0016] Preferably, the clamping device further includes a first limit switch, a second limit switch, and a travel guide. The first limit switch and the second limit switch are mounted on the same horizontal axis. The travel guide includes: a locking part fixed to the connector by bolts, a guide part integrally formed with the locking part and extending vertically, and a first guide head and a second guide head respectively disposed at both ends of the guide part.

[0017] When the connector drives the travel guide to move along the length of the base, the first guide head and the guide part move on the first travel switch to trigger the first travel switch, and the second guide head disengages from the second travel switch and triggers the second travel switch to limit the displacement travel of the push-pull rod.

[0018] This invention also addresses the above-mentioned problems by providing a wafer surface inspection method, comprising the aforementioned wafer surface inspection clamping device system, and further comprising the following steps:

[0019] S1: The wafer is horizontally transferred to the top of the worktable, and the bottom surface of the wafer contacts the support surface of the jaws of multiple clamping devices;

[0020] S2: The telescopic stepper motors of multiple clamping devices are controlled by the worktable to synchronously drive the push-pull rod, thereby moving the limit block from the first position to the second position;

[0021] When the limit block triggers the proximity switch, the gripper presses against the periphery of the wafer, and the proximity switch sends a feedback signal to the control system.

[0022] If the limit block of any group of grippers fails to trigger the proximity switch, the control system immediately resets the grippers, moves them back to the third position, and then moves them back to the second position until all proximity switches are triggered.

[0023] S3: Drive the worktable to move multiple clamping devices and wafers along the horizontal guide rail, positioning the wafer center directly below the detection unit;

[0024] S4: The inspection module of the detection unit reciprocates along the wafer radius direction. When the scanning path is about to reach the gripper of any clamping device, an avoidance step is performed for the gripper.

[0025] Preferably, the method further includes the following steps:

[0026] S5: Repeat step S4 to make the inspection module perform a full-coverage scan of the wafer surface;

[0027] S6: The drive stage moves the wafer back to its initial position, the grippers of multiple clamping devices move synchronously, the telescopic stepper motor drives the push-pull rod, and the limit block moves from the second position back to the first position. The limit block is removed from the detection range of the proximity switch, and the proximity switch signal is turned off.

[0028] S7: Remove the wafer from the clamping device and move it out of the worktable area. All jaws return to the third position for standby.

[0029] Preferably, the avoidance step in step S4 includes:

[0030] S400: Control the clamping device to move, so that the gripper and the limiting block retract from the second position to the third position, the limiting block is removed from the detection range of the proximity switch, and the proximity switch signal is turned off;

[0031] S401: The inspection module completes the scanning through the original area blocked by the gripper, while the gripper of the remaining clamping device keeps the limiting block in the second position;

[0032] S402: After the inspection module completes the scanning of the area, control the clamping device to move, so that the gripper and the limiting block return from the third position to the second position, and the limiting block re-triggers the proximity switch.

[0033] The beneficial effects of this invention are as follows: A proximity switch is set in the clamping device, and the sensing end of the proximity switch is directly opposite the limit position when the jaws grip the wafer. The clamping action is monitored in real time to ensure that each clamping action can be accurately monitored. When the proximity switch is not triggered, it indicates that the wafer clamping is abnormal. The system will automatically initialize the jaws and try to clamp again, thereby effectively avoiding the problem of wafer falling due to the jaws not clamping tightly. This effectively improves the working reliability of the clamping device. In high-speed production environments, it can also ensure the safe clamping and release of wafers, reduce downtime caused by equipment failure or operational errors, and thus improve the efficiency and output of the overall production line. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of a clamping device system for wafer surface inspection.

[0035] Figure 2 This is a schematic diagram of the clamping device and the wafer structure;

[0036] Figure 3 This is a schematic diagram of the clamping device in Embodiment 1.

[0037] Figure 4 This is a schematic diagram of the clamping device and the wafer in this embodiment.

[0038] Figure 5 This is a top view of the proximity switch in Embodiment 1;

[0039] Figure 6 This is a schematic diagram of the proximity switch in Embodiment 1.

[0040] Figure 7 This is a schematic diagram of the stroke guide in Embodiment 1.

[0041] Figure 8 for Figure 2 A magnified view of a section at point A in the middle;

[0042] Figure 9 This is a schematic diagram of the clamping device in Embodiment 2.

[0043] Explanation of reference numerals in the attached figures:

[0044] 1. Workbench; 100. Wafer;

[0045] 2. Clamping device; 20. Telescopic stepper motor; 21. Base; 22. Push-pull rod; 23. Gripper; 24. Proximity switch; 25. Limit block; 26. Positioning plate; 27. Connector; 28. Travel guide; 201. First positioning part; 202. Second positioning part; 203. First limit part; 204. Second limit part; 205. Sliding groove; 206. Through hole; 207. Threaded hole; 208. First connecting part; 209. 210. Second connecting part; 211. Third connecting part; 212. Guide rod; 213. First limiting ring; 214. Second limiting ring; 215. Compression spring; 216. Guide seat; 217. Guide hole; 218. Guide post; 219. Support surface; 220. Abutting surface; 221. First limit switch; 222. Second limit switch; 223. Locking part; 224. Guide part; 225. First guide head; 226. Second guide head. Detailed Implementation

[0046] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0047] Example 1

[0048] like Figures 1 to 8As shown, a wafer surface inspection clamping device system includes multiple clamping devices 2 arranged in a ring around a worktable 1 for clamping externally fed wafers 100. Each clamping device 2 includes: a telescopic stepper motor 20, a base 21 disposed on the side of the telescopic stepper motor 20, a push-pull rod 22 connected to the drive end of the telescopic stepper motor 20, and a gripper 23 disposed at the front end of the push-pull rod 22. The push-pull rod 22 moves along the base 21 as a guide. A proximity switch 24 is mounted on the base 21. A limit block 25 is fixed on the push-pull rod 22, and the limit block 25 has a first position, a second position, and a third position on the base 21. The lever 22 is driven by the telescopic stepper motor 20 to move the limiting block 25 on the base 21 along the first position, the second position, and the third position. When the push-pull lever 22 moves the limiting block 25 to the first position, the limiting block 25 is outside the detection range of the proximity switch 24, and the gripper 23 contacts the bottom wall of the wafer 100. When the push-pull lever 22 moves the limiting block 25 to the second position, the limiting block 25 triggers the proximity switch 24, and the gripper 23 fully clamps the periphery of the wafer 100. When the push-pull lever 22 moves the limiting block 25 to the third position, the limiting block 25 moves away from the proximity switch 24, and the gripper 23 releases the wafer 100 and resets it to the initial position.

[0049] Multiple clamping devices 2 are arranged around the worktable 1 to safely and accurately clamp externally fed wafers 100. Each clamping device 2 includes a telescopic stepper motor 20, a base 21 located on the side of the motor, a push-pull rod 22 connected to the motor drive end, and a gripper 23 located at the front end of the push-pull rod 22. The push-pull rod 22 moves along the base 21. In this embodiment, a proximity switch 24 is installed on the base 21, and a limit block 25 is fixed on the push-pull rod 22. The limit block 25 has three predetermined positions on the base 21: a first position, a second position, and a third position. Driven by the telescopic stepper motor 20, the push-pull rod 22 moves the limit block 25 between these three positions, achieving effective control of the wafer 100. When the limit block 25 is in the first position... In the first position, it is outside the detection range of the proximity switch 24, and at this time, the gripper 23 only contacts and supports the bottom wall of the wafer 100. When it moves to the second position, the limit block 25 triggers the proximity switch 24, indicating that the gripper 23 has completely clamped the periphery of the wafer 100, ensuring the stability of the clamping. When it reaches the third position, the limit block 25 moves away from the proximity switch 24, the gripper 23 releases the wafer 100 and resets to the initial state. This not only improves the safety and reliability of the clamping operation, but also avoids the risk of the wafer 100 falling due to the gripper 23 not clamping the worktable 1 properly during the movement of the wafer by real-time monitoring of the clamping status. Especially in the wafer 100 surface inspection environment that is suitable for high precision and fast response requirements, it improves the efficiency and output of the entire production line.

[0050] It should be noted that the telescopic stepper motor 20 is telescopically operated by a stepper motor in conjunction with a lead screw and a nut. The output end of the stepper motor drives the lead screw to rotate, thereby causing the nut to telescopically move the push-pull rod 22 back and forth along the length of the base 21. The base 21 and the push-pull rod 22 are set to the left and right sides of the motor according to the situation of the worktable 1, so as to adapt to the layout on the worktable 1.

[0051] Specifically, such as Figure 2 , Figure 3 , Figure 3 and Figure 4 As shown, a positioning plate 26 is installed at the end of the base 21 near the gripper 23. The positioning plate 26 includes a first positioning part 201 that is vertically fixed to the end face of the base 21 and a second positioning part 202 that extends horizontally outward from the first positioning part 201 along the width direction of the worktable 1. A proximity switch 24 is installed at the end of the second positioning part 202 along the length direction of the base, and the sensing end of the proximity switch 24 is directly opposite the movement path of the limit block 25.

[0052] A positioning plate 26 is installed at the end of the base 21 near the gripper 23. The positioning plate 26 consists of a first positioning part 201 vertically fixed to the end face of the base 21 and a second positioning part 202 extending horizontally outward from the first positioning part 201 along the width direction of the worktable 1. The first positioning part 201 and the second positioning part 202 are in an inverted "L" structure. The proximity switch 24 is vertically installed at the end of the second positioning part 202, with its sensing end facing the movement path of the limit block 25. This design ensures that the proximity switch 24 can accurately monitor the position change of the limit block 25, thereby providing real-time feedback on the clamping status. When the push-pull rod 22 moves the limit block 25, the proximity switch 24 can accurately detect whether the limit block 25 has reached the predetermined position, ensuring that the gripper 23 correctly clamps or releases the wafer 100. This not only improves the response speed and accuracy of the system, but also enhances the safety and reliability of the entire clamping process, effectively preventing damage to the wafer 100 caused by improper clamping.

[0053] Furthermore, such as Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the limiting block 25 includes a first limiting part 203 and a second limiting part 204. The first limiting part 203 has a longitudinal sliding groove 205 and a through hole 206 at the bottom of the groove. The second limiting part 204 extends radially outward from the first limiting part 203 along the worktable 1 and is parallel to the second positioning part 202. The push-pull rod 22 is provided with a threaded hole 207 for mounting screws. The screw passes through the through hole 206, and the threaded section of the bolt is connected to the threaded hole 207. The bolt head abuts against the sliding groove 205. The second limiting part 204 is aligned with the sensing end of the proximity switch 24.

[0054] The limiting block 25 includes a first limiting part 203 and a second limiting part 204. The first limiting part 203 has a longitudinal sliding groove 205 and a through hole 206 at the bottom of the groove. The second limiting part 204 extends radially outward from the first limiting part 203 along the worktable 1 and is parallel to the second positioning part 202. The first limiting part 203 and the second positioning part 202 form an "L" structure. The push-pull rod 22 has a threaded hole 207. The screw passes through the through hole 206 of the first limiting part 203 and connects to the threaded hole 207 on the push-pull rod 22. The head rests against the sliding groove 205 to ensure that the limiting block 25 is firmly fixed on the push-pull rod 22 and allows for a certain range of adjustment on the push-pull rod 22. The design of the second limiting part 204 ensures that its surface is precisely aligned with the sensing end of the proximity switch 24, ensuring that the proximity switch 24 can be accurately triggered during the movement of the limiting block 25. Through this design, the system can achieve precise control of the clamping action, improve the stability and accuracy of the clamping operation, and reduce failures caused by mechanical errors, further ensuring the stability of the wafer 100 during the inspection process.

[0055] Specifically, such as Figure 2 and Figure 3 As shown, the drive end of the telescopic stepper motor 20 is provided with a connector 27. The connector 27 includes a first connecting part 208 and a second connecting part 209 arranged in parallel, and a third connecting part 210 that vertically connects the two. The drive end of the telescopic stepper motor 20 is fixed to the first connecting part 208, the tail end of the push-pull rod 22 is fixed to the second connecting part 209, the front end of the third connecting part 210 is connected to the first connecting part 208, and the rear end of the third connecting part 210 is connected to the second connecting part 209.

[0056] The drive end of the telescopic stepper motor 20 is provided with a connector 27, which consists of a first connecting part 208 and a second connecting part 209 arranged in parallel, and a third connecting part 210 that vertically connects the two. The drive end of the telescopic stepper motor 20 is fixed to the first connecting part 208, while the tail of the push-pull rod 22 is fixed to the second connecting part 209. The third connecting part 210 is connected to the first connecting part 208 from the front end and to the second connecting part 209 from the rear end, forming a stable structural frame. This not only ensures that the telescopic stepper motor 20 can effectively transmit power to the push-pull rod 22, but also enhances the mechanical stability of the entire clamping device 2, allowing the push-pull rod 22 to move back and forth under precise control, ensuring that the gripper 23 can accurately and stably clamp or release the wafer 100.

[0057] Furthermore, such as Figure 2 and Figure 3As shown, a guide rod 211 is provided at the tail of the push-pull rod 22. A first limiting ring 212 is connected to the front end of the guide rod 211. The guide rod 211 passes through the second connecting part 209. A second limiting ring 213 is sleeved on the rear end of the guide rod 211. The second limiting ring 213 is in close contact with the rear end face of the second connecting part 209 to limit the retraction stroke of the guide rod 211.

[0058] The push-pull rod 22 has a guide rod 211 at its tail. A first limiting ring 212 is connected to the front end of the guide rod 211, which passes through the second connecting part 209. A second limiting ring 213 is fitted onto the rear end of the guide rod 211. The rear end of the guide rod 211 is in close contact with the rear end face of the second connecting part 209. This design ensures good guidance and positioning accuracy of the push-pull rod 22 during extension and retraction, avoiding operational errors or equipment damage caused by misalignment of the guide rod 211. In this way, the system can maintain a high degree of consistency during operation.

[0059] Furthermore, such as Figure 2 and Figure 3 As shown, a compression spring 214 is sleeved on the guide rod 211. One end of the compression spring 214 abuts against the front end face of the second connecting part 209, and the other end of the compression spring 214 abuts against the rear end face of the first limiting ring 212. The compression spring 214 is in a pre-compressed state and is used to provide elastic clamping force to the push-pull rod 22.

[0060] A compression spring 214 is also fitted on the guide rod 211. One end of the spring abuts against the front end face of the second connecting part 209, and the other end abuts against the rear end face of the first limiting ring 212. The compression spring 214 is always in a pre-compressed state, providing a constant elastic clamping force for the push-pull rod 22. This design allows the gripper 23 to obtain appropriate clamping force when clamping the wafer 100. It will not cause the wafer 100 to slip due to insufficient force, nor will it damage the wafer 100 due to excessive force. In addition, the compression spring 214 in the pre-compressed state can also absorb and buffer the vibration and impact during the clamping process. As the limiting block 25 moves repeatedly with the push-pull rod 22 from the first position to the second position, or from the third position to the second position, it can ensure that the limiting block 25 and the proximity switch 24 maintain a precise detection position, which improves the safety and accuracy of the clamping operation and ensures the integrity and safety of the wafer 100 in the entire inspection process.

[0061] Specifically, such as Figure 2 , Figure 3 and Figure 6As shown, the rear end of the gripper 23 is fixed to the front end of the push-pull rod 22 by bolts. The front end of the gripper 23 is provided with a horizontal support surface 218 and a vertical abutment surface 219. When the push-pull rod 22 drives the limiting block 25 to the first position, the support surface 218 supports the bottom surface of the wafer 100, and the abutment surface 219 has a gap with the periphery of the wafer 100. When the push-pull rod 22 drives the limiting block 25 to the second position, the support surface 218 supports the bottom surface of the wafer 100, and the abutment surface 219 presses against the periphery of the wafer 100.

[0062] The gripper 23 is fixed to the front end of the push-pull rod 22 by bolts. The front end of the gripper 23 is provided with a horizontal support surface 218 and a perpendicular abutment surface 219, which are used to provide stable support during the clamping process. When the push-pull rod 22 drives the limiting block 25 to the first position, the support surface 218 contacts and supports the bottom surface of the wafer 100, while the abutment surface 219 does not contact the periphery of the wafer 100. When the push-pull rod 22 moves further and the limiting block 25 reaches the second position, the support surface 218 continues to support the bottom surface of the wafer 100, while the abutment surface 219 presses against the periphery of the wafer 100 to complete the clamping action. This design allows the gripper 23 to flexibly adjust the contact state with the wafer 100 as needed, which not only ensures the stability of the clamping process, but also avoids unnecessary pressure or damage to the wafer 100, thereby improving the operating accuracy and safety of the entire clamping device 2.

[0063] It is worth mentioning that, such as Figure 7 The support surface 218 has an arc-shaped transition surface at both the front and back. In this embodiment, the gripper moves from the first position to the second position, or the gripper 23 moves from the third position to the second position, to ensure that the bottom surface and periphery of the wafer 100 will not be damaged due to minor misalignment of the planar precision, thus effectively protecting the wafer 100.

[0064] Furthermore, such as Figure 2 , Figure 3 and Figure 8 As shown, the clamping device 2 also includes a first limit switch 220, a second limit switch 221, and a travel guide 28. The first limit switch 220 and the second limit switch are mounted on the same horizontal axis. The travel guide 28 includes: a locking part 222 fixed to the connector 27 by bolts, a guide part 223 integrally formed with the locking part 222 and extending vertically, and a first guide head 224 and a second guide head 225 respectively disposed at both ends of the guide part 223. When the connector 27 drives the travel guide 28 to move along the length direction of the base 21, the first guide head 224 and the guide part 223 move on the first limit switch 220 to trigger the first limit switch 220, and the second guide head 225 disengages from the second limit switch 221 and triggers the second limit switch 221 to limit the displacement stroke of the push-pull rod 22.

[0065] The clamping device 2 also includes a first limit switch 220, a second limit switch 221, and a travel guide 28. The first limit switch 220 and the second limit switch 221 are mounted on the worktable 1 along the same horizontal axis to accurately monitor the displacement of the push-pull rod 22. The travel guide 28 consists of a locking part 222, a guiding part 223, and a first guide head 224 and a second guide head 225 respectively located at both ends of the guiding part 223. In this embodiment, the locking part 222 is fixed to the first connecting part 208 of the connector 27 by bolts, and the guiding part 222... 3 is integrally formed with the locking part 222 and extends vertically. When the connecting part 27 drives the travel guide 28 to move along the length direction of the base 21, the first guide head 224 and the guide part 223 move on the first travel switch 220 to trigger the switch. At the same time, the second guide head 225 disengages from the second travel switch 221 and triggers it, thereby limiting the displacement travel of the push-pull rod 22. Through the combined use of the dual travel switches, the precise positioning and safe control of the push-pull rod 22 during operation are ensured, and the working reliability and response speed of the entire clamping device 2 are enhanced.

[0066] Example 2

[0067] like Figure 9 As shown, a wafer surface inspection clamping device system includes a telescopic stepper motor 20, a base 21, a push-pull rod 22, a gripper 23, a limit block 25, a proximity switch 24, a first limit switch 220, a second limit switch 221, and a travel guide 28.

[0068] A pair of guide seats 215 are provided on the base 21 along its length direction. A guide hole 216 is provided in the guide seat 215. A pair of guide posts 217 are provided on the push-pull rod 22. The guide posts 217 are slidably inserted into the guide hole 216. The limiting block 25 is provided in the middle of the push-pull rod 22 and is located between the two guide posts 217.

[0069] This second embodiment is a variation of the first embodiment. The first limit switch 220 and the second limit switch 221 are mounted on the base along the same horizontal axis to adapt to the layout on the workbench 1. The push-pull rod 22 is changed from a long strip structure to a cylindrical structure. The structures of the limiting block 25 and the positioning plate 26 are adjusted. The two adjacent ends of the first limiting part 203 and the second limiting part 204 of the limiting block 25 are connected. The first limiting part 203 and the second limiting part 204 are generally parallel. The first limiting part 203 has a base plate, which cooperates with the first limiting part 203 to clamp the push-pull rod 22. Two screws on the first limiting part 203 are tightened to connect the base plate clamping the push-pull rod 22. The first limiting part 203 and the second limiting part 204 of the limiting block 25 are parallel. The two limiting parts 204 are aligned with the sensing end of the proximity switch 24. In addition, the base 21 is provided with a pair of guide seats 215 along its length, and each guide seat 215 has a guide hole 216. The push-pull rod 22 is equipped with a pair of guide posts 217. These guide posts 217 are slidably inserted into the guide holes 216 to ensure that the push-pull rod 22 can move smoothly along the predetermined path. The limiting block 25 is located in the middle of the push-pull rod 22 and between the two guide posts 217. This design not only ensures the straightness and stability of the push-pull rod 22 during the extension and retraction process, but also effectively prevents inaccurate clamping problems caused by offset or vibration. Through this structure, the system can achieve precise and stable clamping of the wafer 100, improving operating efficiency.

[0070] A method for inspecting the surface of a wafer includes the following steps:

[0071] S1: The external transfer unit horizontally transfers the wafer 100 to the top of the worktable 1, and then moves downward until the bottom surface of the wafer 100 contacts the support surface 218 of the gripper 23 of the eight clamping devices 2. The transfer unit continues to descend until it is completely separated from the wafer 100 and then withdraws from the worktable 1 area.

[0072] S2: The worktable 1 controls the telescopic stepper motors 20 of the eight clamping devices 2 to synchronously drive the push-pull rods 22, which in turn move the limit block 25 from the first position to the second position.

[0073] When the limit block 25 triggers the proximity switch 24, the gripper 23 presses the periphery of the wafer 100 against the abutment surface 219, and the proximity switch 24 sends a feedback signal to the control system.

[0074] If the limit block 25 of any group of grippers 23 fails to trigger the proximity switch 24, the control system immediately resets the gripper 23, returns it to the third position, and then moves it back to the second position until all proximity switches 24 are triggered.

[0075] S3: The worktable 1 moves the eight clamping devices 2 and the wafer 100 along the horizontal guide rail until the center of the wafer 100 is positioned directly below the detection unit;

[0076] S4: The inspection module of the detection unit reciprocates along the radius of the wafer 100. When the scanning path is about to reach directly above a certain gripper 23, the gripper performs the following steps:

[0077] S400 avoidance action: The telescopic stepper motor 20 corresponding to the gripper 23 drives the push-pull rod 22, which drives the limit block 25 to retract from the second position to the third position. The limit block 25 is out of the detection range of the proximity switch 24, the signal of the proximity switch 24 is turned off, and the second limit switch 221 is triggered and sends a feedback signal.

[0078] S401 Scanning Execution: The inspection module completes the scan through the original blocked area of ​​the gripper 23, while the remaining seven grippers 23 keep the limiting block 25 in the second position;

[0079] S402 Reset Action: After scanning is completed, the gripper 23 telescopic stepper motor 20 drives the push-pull rod 22, which drives the limit block 25 from the third position back to the second position. The limit block 25 re-triggers the proximity switch 24, and the signal of the second limit switch 221 is extinguished.

[0080] S5: Repeat step S4 to make the inspection module perform two full-coverage scans on the surface of wafer 100;

[0081] S6: The worktable 1 moves the wafer 100 back to the initial position, the eight grippers 23 move synchronously, the telescopic stepper motor 20 drives the push-pull rod 22, and moves the limit block 25 from the second position back to the first position. The limit block 25 is removed from the detection range of the proximity switch 24, the signal of the proximity switch 24 is turned off, the support surface 218 supports the bottom surface of the wafer 100, and the gripper 23 abutting surface 219 is removed from the periphery of the wafer 100.

[0082] S7: The external transfer unit moves to below the wafer 100 and lifts the wafer 100 until the bottom surface of the wafer 100 is completely separated from the support surface 218 of the gripper 23. The transfer unit then moves the wafer 100 out of the worktable 1 area, and all grippers 23 return to the third position for standby.

[0083] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A wafer surface inspection clamping device system, wherein multiple clamping devices (2) are arranged in a ring around a worktable (1) for clamping externally fed wafers (100), the clamping devices (2) comprising: The system comprises a telescopic stepper motor (20), a base (21) disposed on the side of the telescopic stepper motor (20), a push-pull rod (22) connected to the drive end of the telescopic stepper motor (20), and a gripper (23) disposed at the front end of the push-pull rod (22). The push-pull rod (22) moves along the base (21) under guidance. Its features are: A proximity switch (24) is installed on the base (21), and a limit block (25) is fixed on the push-pull rod (22). The limit block (25) has a first position, a second position and a third position on the base (21). The push-pull rod (22) is driven by a telescopic stepper motor (20) to move the limit block (25) along the first position, the second position and the third position on the base (21). When the push-pull rod (22) moves the limiting block (25) to the first position, the limiting block (25) is outside the detection range of the proximity switch (24), and the gripper (23) contacts the bottom wall of the wafer (100); when the push-pull rod (22) moves the limiting block (25) to the second position, the limiting block (25) triggers the proximity switch (24) and the gripper (23) fully clamps the periphery of the wafer (100); when the push-pull rod (22) moves the limiting block (25) to the third position, the limiting block (25) moves away from the proximity switch (24) and the gripper (23) releases the wafer (100) and resets it to the initial position; The rear end of the gripper (23) is fixed to the front end of the push-pull rod (22) by bolts. The front end of the gripper (23) is provided with a horizontal support surface (218) and a vertical abutment surface (219). When the push-pull rod (22) drives the limiting block (25) to the first position, the support surface (218) supports the bottom surface of the wafer (100), and the abutment surface (219) has a gap with the periphery of the wafer (100). When the push-pull rod (22) drives the limiting block (25) to the second position, the support surface (218) supports the bottom surface of the wafer (100), and the abutment surface (219) presses against the periphery of the wafer (100). The clamping device system also includes a control system, which is electrically connected to the proximity switch (24) and the telescopic stepper motor (20), and is configured to: When the limit block (25) triggers the proximity switch (24), the gripper (23) presses against the periphery of the wafer (100), and the proximity switch (24) sends a feedback signal to the control system. If the limit block (25) of any set of grippers (23) does not trigger the proximity switch (24), the control system immediately executes the gripper (23) reset, returns to the third position, and then moves back to the second position until all proximity switches (24) are triggered.

2. The wafer surface inspection clamping device system according to claim 1, characterized in that: A positioning plate (26) is installed at the end of the base (21) near the gripper (23). The positioning plate (26) includes a first positioning part (201) vertically fixed to the end face of the base (21) and a second positioning part (202) extending horizontally outward from the first positioning part (201) along the width direction of the worktable (1). The proximity switch (24) is installed at the end of the second positioning part (202) along the length direction of the base. The sensing end of the proximity switch (24) is directly opposite the moving path of the limit block (25).

3. The wafer surface inspection clamping device system according to claim 2, characterized in that: The limiting block (25) includes a first limiting part (203) and a second limiting part (204). The first limiting part (203) has a longitudinal sliding groove (205) and a through hole (206) at the bottom of the groove. The second limiting part (204) extends radially outward from the first limiting part (203) along the worktable (1) and is parallel to the second positioning part (202). The push-pull rod (22) is provided with a threaded hole (207) for mounting screws. The screw passes through the through hole (206), the threaded section of the bolt is connected to the threaded hole (207), and the bolt head abuts against the sliding groove (205). The second limiting part (204) is aligned with the sensing end of the proximity switch (24).

4. The wafer surface inspection clamping device system according to claim 1, characterized in that: The drive end of the telescopic stepper motor (20) is provided with a connector (27). The connector (27) includes a first connecting part (208) and a second connecting part (209) arranged in parallel and a third connecting part (210) that vertically connects the two. The drive end of the telescopic stepper motor (20) is fixed to the first connecting part (208), the tail of the push-pull rod (22) is fixed to the second connecting part (209), the front end of the third connecting part (210) is connected to the first connecting part (208), and the rear end of the third connecting part (210) is connected to the second connecting part (209).

5. The wafer surface inspection clamping device system according to claim 4, characterized in that: The push-pull rod (22) is provided with a guide rod (211) at its tail end. A first limiting ring (212) is connected to the front end of the guide rod (211). The guide rod (211) passes through a second connecting part (209). A second limiting ring (213) is sleeved on the rear end of the guide rod (211). The second limiting ring (213) is in close contact with the rear end face of the second connecting part (209) to limit the retraction stroke of the guide rod (211).

6. The wafer surface inspection clamping device system according to claim 5, characterized in that: A compression spring (214) is fitted on the guide rod (211). One end of the compression spring (214) abuts against the front end face of the second connecting part (209), and the other end of the compression spring (214) abuts against the rear end face of the first limiting ring (212). The compression spring (214) is in a pre-compressed state and is used to provide elastic clamping force to the push-pull rod (22).

7. The wafer surface inspection clamping device system according to claim 1, characterized in that: A pair of guide seats (215) are provided on the base (21) along its length direction. A guide hole (216) is provided in the guide seat (215). A pair of guide posts (217) are provided on the push-pull rod (22). The guide posts (217) are slidably inserted into the guide hole (216). The limiting block (25) is provided in the middle of the push-pull rod (22) and is located between the two guide posts (217).

8. The wafer surface inspection clamping device system according to claim 4, characterized in that: The clamping device (2) further includes a first limit switch (220), a second limit switch (221), and a travel guide (28). The first limit switch (220) and the second limit switch are mounted on the same horizontal axis. The travel guide (28) includes: a locking part (222) fixed to the connector (27) by bolts, a guide part (223) integrally formed with the locking part (222) and extending vertically, and a first guide head (224) and a second guide head (225) respectively provided at both ends of the guide part (223). When the connector (27) drives the travel guide (28) to move along the length of the base (21), the first guide (224) and the guide part (223) move on the first travel switch (220) to trigger the first travel switch (220), and the second guide (225) disengages from the second travel switch (221) and triggers the second travel switch (221) to limit the displacement stroke of the push-pull rod (22).

9. A method for inspecting the surface of a wafer, comprising the wafer surface inspection clamping device system of claim 8, characterized in that, It also includes the following steps: S1: The wafer (100) is horizontally moved above the worktable (1) so that the bottom surface of the wafer (100) contacts the jaws (23) of the multiple clamping devices (2); S2: The telescopic stepper motors (20) of multiple clamping devices (2) controlled by the worktable (1) synchronously drive the push-pull rod (22), thereby moving the limit block (25) from the first position to the second position; S3: Drive the worktable (1) to move multiple clamping devices (2) and wafer (100) along the horizontal guide rail, and position the center of wafer (100) directly below the detection unit; S4: The inspection module of the detection unit scans back and forth along the radius of the wafer (100). When the scanning path is about to reach the gripper (23) of any clamping device (2), an avoidance step is performed for the gripper.

10. The detection method for wafer surface inspection according to claim 9, characterized in that, It also includes the following steps: S5: Repeat step S4 to make the inspection module perform a full-coverage scan of the wafer (100) surface; S6: The drive table (1) moves the wafer (100) back to the initial position. The grippers (23) of multiple clamping devices (2) move synchronously. The telescopic stepper motor (20) drives the push-pull rod (22) to move the limit block (25) from the second position back to the first position. The limit block (25) is removed from the detection range of the proximity switch (24), and the signal of the proximity switch (24) is turned off. S7: Remove the wafer (100) from the clamping device (2) and move it out of the worktable (1) area. All grippers (23) return to the third position for standby.

11. The detection method for wafer surface inspection according to claim 9, characterized in that, The avoidance step in step S4 includes: S400: Control the clamping device (2) to move, so that the gripper (23) and the limiting block (25) retract from the second position to the third position, the limiting block (25) is removed from the detection range of the proximity switch (24), and the signal of the proximity switch (24) is turned off; S401: The inspection module completes the scanning through the original blocked area of ​​the gripper (23), while the grippers (23) of the other clamping devices (2) keep the limiting block (25) in the second position; S402: After the inspection module completes the scanning of the area, control the clamping device (2) to move, so that the gripper (23) and the limit block (25) return from the third position to the second position, and the limit block (25) re-triggers the proximity switch (24).

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