A collapsible gripper device

Abstract

This utility model discloses a collapsible gripper device, including a pair of side arms and a drive mechanism. Grippers are provided on the inner surfaces of the side arms, and a collapsible structure exists between the grippers and the side arms. The collapsible structure includes a mounting groove on the inner surface of the side arms, a connecting block connected to the grippers within the mounting groove, and a buffer area formed by a gap between the connecting block and the mounting groove. A support shaft is connected within the grippers. A first through hole and a second through hole are provided on the connecting block and the side arms. The second through hole is divided into a coarse section and a fine section. A compression spring fitted onto the support shaft is provided within the coarse section. A guide shaft is connected within the connecting block. A through hole is provided on the side arms, and the free end of the guide shaft passes through the through hole. A contact sensor is provided on the outer surface of the side arms. In this way, the compression spring and the buffer area effectively offset part of the clamping impact force transmitted by the grippers, converting the rigid contact force between the grippers and the wafer into a flexible buffer force, preventing the wafer from breaking due to excessive clamping force directly squeezing it.

Description

Technical Field

[0001] This utility model relates to the semiconductor field, specifically to a gripper device with a collapsible mechanism. Background Technology

[0002] With the rapid development of high-end technologies in the integrated circuit semiconductor field, such as wafer transportation, manufacturing, and packaging, semiconductor process equipment is facing increasingly stringent performance requirements. It not only needs to adapt to the improvement of wafer processing precision, but also needs to meet the core requirements of efficient production, stable operation, and clean processing. Among them, the wafer clamping and flipping process is a key step that connects multiple processes, and its reliability and accuracy directly affect the capacity and product yield of the entire process system.

[0003] In semiconductor manufacturing, wafers undergo multiple processes, each with significantly different operational requirements for the wafer surface. For example, core chip manufacturing processes must be completed on the front of the wafer, while barcodes for wafer identification must be etched on the back. When the process switches to specific surface operations (such as accessing the back when identifying wafer information via a barcode reader), or when double-sided quality inspection and orientation adjustment are required before the wafer enters the core process equipment, the wafer must first be stably fixed using a clamping device, and then flipped to precisely align the surface to be processed with the equipment station. Therefore, the wafer clamping and flipping functions have become a core element in ensuring smooth workflow and preventing process interruptions.

[0004] Currently, wafer clamping devices in the industry use cylinders as clamping drive components, achieving clamping through direct contact between the grippers and the wafer. However, the cylinder-driven grippers result in a rigid, hard contact between the grippers and the wafer. This makes the wafer highly susceptible to damage such as breakage and surface scratches due to excessive instantaneous impact force when the clamping force is miscontrolled or there are minor alignment errors, significantly reducing product yield. Utility Model Content

[0005] Based on this, and in response to the aforementioned technical problems, this utility model provides a gripper device with a collapsible mechanism.

[0006] The objective of this utility model can be achieved through the following technical solutions:

[0007] A collapsible gripper device includes a pair of side arms disposed on the upper surface of a base plate, grippers disposed on the inner surfaces of each side arm, and a drive mechanism for driving the two side arms to move synchronously towards each other to cause the grippers to clamp a wafer; the grippers and the side arms have a collapsible structure, the collapsible structure including a mounting groove disposed on the inner surface of the side arm, a connecting block connected to the grippers disposed in the mounting groove, a buffer area formed by a gap between the connecting block and the mounting groove, a horizontal support shaft connected in the grippers, and a first through hole and a second through hole respectively disposed on the connecting block and the side arm at positions corresponding to the support shaft. The support shaft has two through holes. The free end of the support shaft passes through the first through hole and the second through hole in sequence. A retaining spring is fitted on the free end of the support shaft on the outside of the side arm. The second through hole is a stepped hole, divided into a thick section and a thin section. A disc spring and a compression spring are fitted on the support shaft in sequence in the thick section. The disc spring contacts the connecting block. One end of the compression spring abuts against the bottom step of the thick section, and the other end abuts against the disc spring. A horizontal guide shaft is connected inside the connecting block. A through hole is provided on the side arm at the position corresponding to the guide shaft. The free end of the guide shaft passes through the through hole. A contact sensor is provided on the outer side of the side arm at the position corresponding to the guide shaft.

[0008] By employing the above technical solution, the compression spring and buffer area in the collapsible structure allow the spring to elastically deform when the grippers contact the wafer and apply clamping force. This effectively counteracts part of the clamping impact force transmitted by the grippers, transforming the rigid contact force between the grippers and the wafer into a flexible buffer force. The buffer area provides displacement space for the grippers and connecting blocks, further weakening the impact force and preventing damage such as cracking or scratching caused by excessive clamping force directly squeezing the wafer. Simultaneously, when completing the current wafer processing and needing to pick up the next wafer, the compression spring releases its stored energy, causing the grippers to return to their initial position, ensuring consistent gripping positions and guaranteeing the accuracy of subsequent clamping actions. Secondly, through the disc spring, when the grippers clamp the wafer, the compression spring first counteracts the initial clamping impact force through elastic deformation. If the clamping force continues to increase, causing the compression spring to compress to its limit, the disc spring immediately takes over the buffering role, continuing to provide flexible support through its own elastic deformation. This prevents the grippers from hard contacting the wafer after the compression spring reaches its limit, thus improving the safety of wafer clamping. Furthermore, through the cooperation of the guide shaft and the contact sensor, when the two driven side arms move synchronously towards each other, causing the grippers to adhere to the wafer, the free end of the guide shaft gradually approaches the contact sensor. When the free end of the guide shaft touches the contact sensor, the contact sensor can immediately provide a feedback signal indicating that the gripping is in place, avoiding the wafer easily falling off due to excessively loose gripping or being damaged due to excessively tight gripping. In addition, the cooperation between the support shaft and the first and second through holes, as well as the cooperation between the guide shaft and the through hole, forms a dual guide, preventing the grippers from shifting or wobbling during the movement of the wafer.

[0009] In this specific embodiment of the invention, the grippers are made of antistatic nylon material. This antistatic nylon gripper provides antistatic properties, effectively suppressing static electricity generated during contact and friction between the gripper and the wafer, thus preventing damage to the wafer circuitry from electrostatic discharge. Furthermore, the antistatic nylon gripper is elastic, forming a flexible fit with the wafer during contact, thereby reducing the risk of scratches and indentations on the wafer surface during clamping.

[0010] In a specific embodiment of this utility model: a bushing fitted onto the guide shaft is fixedly installed inside the through hole of the side arm. With this structure, the direct fit between the guide shaft and the through hole of the side arm is prone to gaps due to machining errors or wear, which can cause radial displacement of the gripper during movement. Thus, by filling the gap between the guide shaft and the through hole with the bushing, the guide shaft is prevented from wobbling during movement, ensuring that the guide shaft always moves stably along a preset horizontal direction, thereby improving guiding accuracy.

[0011] In a specific embodiment of this utility model: the bushing is an oil-free bushing. Using an oil-free bushing eliminates the need for additional lubricating oil, thereby reducing wafer contamination.

[0012] In this specific embodiment of the invention: the connecting block is an Invar connecting block, and the support shaft is an Invar support shaft. This structure, due to the extremely low coefficient of thermal expansion of Invar steel, avoids temperature stress causing preload drift in the compression spring.

[0013] In a specific embodiment of this utility model: a base is provided below the base plate, a rotary motor is fixed on the base, and the base plate is fixed on the output end of the rotary motor.

[0014] In summary, this invention utilizes the compression spring and buffer area in the collapsible structure. When the grippers contact the wafer and apply clamping force, the compression spring undergoes elastic deformation, effectively offsetting part of the clamping impact force transmitted by the grippers. This transforms the rigid contact force between the grippers and the wafer into a flexible buffer force. The buffer area provides displacement space for the grippers and connecting blocks, further weakening the impact force and preventing damage such as cracking or scratches caused by excessive clamping force directly squeezing the wafer. Secondly, through the cooperation of the guide shaft and the contact sensor, when the two side arms move synchronously towards each other until the grippers are in contact with the wafer, the free end of the guide shaft gradually approaches the contact sensor. When the free end of the guide shaft touches the contact sensor, the contact sensor can immediately provide a clamping signal, preventing the wafer from easily falling off due to excessively loose clamping or being damaged due to excessively tight clamping. Furthermore, the cooperation between the support shaft and the first and second through holes, as well as the cooperation between the guide shaft and the through hole, forms a double guiding structure, preventing the grippers from wobbling during wafer clamping. In addition, with the disc spring, when the jaws hold the wafer, the compression spring first offsets the initial clamping impact force through elastic deformation; if the clamping force continues to increase and causes the compression spring to compress to its limit position, at this time, the disc spring can immediately take on the buffering role and continue to provide flexible support through its own elastic deformation, so as to avoid the jaws from hard contacting the wafer after the compression spring reaches its limit, which would cause the wafer to be crushed, thus improving the safety of wafer clamping. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings.

[0016] Figure 1 This is a schematic diagram of the structure of a collapsible gripper device according to the present invention;

[0017] Figure 2 The gripper is mounted on the side arm via a collapsible structure;

[0018] Figure 3 This is a cross-sectional view of the collapsed structure. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0020] Please see Figure 1 As shown, this utility model is a collapsible gripper device, including a pair of side arms 12 disposed on the upper surface of the base plate 10. Each side arm 12 has two grippers 13 spaced apart vertically on its inner side. It also includes a drive mechanism 20 for driving the two side arms 12 to move synchronously towards each other, thereby driving the grippers 13 to clamp the wafer 6.

[0021] In this embodiment, the gripper 13 is made of antistatic nylon material. This antistatic nylon gripper provides antistatic properties, effectively suppressing static electricity generated during contact and friction between the gripper and the wafer, thus preventing damage to the wafer circuitry from electrostatic discharge. Furthermore, the antistatic nylon gripper is elastic, forming a flexible fit with the wafer during contact, thereby reducing the risk of scratches and indentations on the wafer surface during clamping.

[0022] In this embodiment, the drive mechanism 20 includes linear guide rails 21 disposed on both sides of the upper surface of the base plate 10, slide blocks 23 longitudinally spanning the two linear guide rails 21 via sliders 22, and a power unit 24 mounted on the base plate 10 and connected to the two slide blocks 23. Two side arms 12 are respectively mounted on corresponding slide blocks 23. Here, the power unit 24 adopts a motor-driven lead screw and nut structure.

[0023] like Figure 1 , Figure 2 and Figure 3 As shown, in this embodiment, a collapsible structure exists between the gripper 13 and the side arm 12. This collapsible structure includes a support shaft 30, a connecting block 31, a compression spring 32, and a disc spring 39. Two mounting grooves 34 are provided on the inner surface of the side arm 12, spaced vertically. Each connecting block 31 is located within its corresponding mounting groove 34. Each connecting block 31 is connected to its corresponding gripper 13 by a bolt 32. A buffer area 35 is formed between the inner surfaces of the connecting block 31 and the mounting groove 34 to cushion the impact force of the gripping action. A mounting hole 131 is provided on the gripper 13. A first through hole 36 and a second through hole 37 are respectively provided on the connecting block 31 and the side arm 12 at positions corresponding to the mounting hole 131. The support shaft 30 is horizontally positioned, with its fixed end threaded into the mounting hole 131 and its free end passing through the first through hole 36 and the second through hole 37 in sequence. A retaining spring 301 is fitted on the free end of the support shaft 30, located outside the side arm 12. A retaining ring 301 is used to limit the displacement of the support shaft 30, thereby preventing the gripper from falling off the side arm 12. The second through hole 37 is a stepped hole, divided into a thick section 371 on the inner side and a thin section 372 on the outer side. A disc spring 39 and a compression spring 32 are located inside the thick section 371 and are fitted onto the support shaft 30. The disc spring 39 contacts the connecting block 31. One end of the compression spring 32 abuts against the bottom step of the thick section 371, and the other end abuts against the disc spring 39, forming an elastic buffer structure, which greatly reduces the risk of the gripper crushing the wafer. Horizontal guide shafts 33 are connected to the four corners of the connecting block 31. The side arm 12 has through holes 121 at the positions corresponding to the guide shafts 33. The free ends of the guide shafts 33 pass through the corresponding through holes 121. A contact sensor 38 is provided on the outer surface of the side arm 12 at the position corresponding to one of the guide shafts 33.

[0024] In this way, the drive mechanism 20 is activated, driving the two side arms 12 to move synchronously towards each other, causing the grippers 13 to contact and adhere to the edges of the wafer 6. As the side arms continue to move, the gripping force of the grippers 13 on the wafer 6 gradually increases. During this process, the grippers 13 first contact and adhere to the edges of the wafer 6, but are stopped by the wafer, and their positions remain unchanged, unable to continue moving towards the center of the wafer 6. Meanwhile, the side arms 12 continue to move towards the center of the wafer 6, and the side arms 12 and the corresponding grippers 13 generate relative displacement. At the same time, the guide shaft 33, which is connected to the grippers 13 through the connecting block 12, gradually approaches the contact sensor 38 mounted on the outer surface of the side arms 12 as the side arms 12 continue to approach the wafer. When the free end 331 of the guide shaft 33 touches the contact sensor 38 on the outer side of the side arm 12, the contact sensor 38 immediately sends a clamping signal to the control system, and the drive mechanism stops. In this way, the clamping force threshold can be precisely controlled, which can prevent the wafer from falling off during subsequent flipping and processing due to excessive clamping, and also prevent the wafer from cracking or surface damage due to excessive clamping, thus ensuring that the clamping state is stable and controllable.

[0025] During the process of the side arm 12 continuously approaching the wafer 6, the side arm 12 and the connecting block 31 form a relative compression of the spring 32. At this time, the spring 32 undergoes elastic deformation under pressure, which can effectively offset part of the clamping impact force transmitted by the gripper 13, transforming the rigid contact force between the gripper and the wafer into a flexible buffer force. The buffer area 35 provides displacement space for the gripper 13 and the connecting block 31, further weakening the instantaneous impact force and preventing damage such as cracks and scratches caused by excessive clamping force directly squeezing the wafer. When the wafer processing is completed and it is necessary to release the wafer and grab the next wafer, the drive mechanism 20 drives the two side arms 12 to move synchronously in opposite directions, i.e., move away from each other. The compressed spring releases its stored elastic potential energy, pushing the connecting block and the gripper back to their initial position when not clamped, ensuring that the stopping position of the gripper remains consistent after each clamping action, avoiding wafer alignment deviation caused by gripper position shift during subsequent clamping, and ensuring repeatability accuracy for continuous processing of multiple wafers. In addition, by adding a disc spring 39, when the jaws clamp the wafer, the compression spring first offsets the initial clamping impact force through elastic deformation; if the clamping force continues to increase and the compression spring is compressed to the limit position, the disc spring 39 can take on the buffering role and continue to provide flexible support through its own elastic deformation, so as to avoid the jaws from hard contacting the wafer after the compression spring reaches its limit and causing the wafer to be crushed, thus further improving the safety of wafer clamping.

[0026] In addition, during the entire clamping process, the cooperation between the support shaft 30 and the first through hole 36 and the second through hole 37, as well as the cooperation between the guide shaft 33 and the through hole 121, forms a dual guide. This not only prevents the gripper 13 from shifting or shaking during the movement of the wafer, but also ensures that the two grippers on both sides maintain a high degree of coaxiality and parallelism when moving synchronously in opposite directions. Ultimately, this ensures that the wafer is accurately positioned in the preset center after being clamped, providing a stable position reference for subsequent wafer rotation, double-sided processing (such as front chip manufacturing and back barcode recognition), and avoiding a decrease in processing accuracy due to wafer eccentricity, thus ensuring the overall process yield.

[0027] In this embodiment, a bushing 122 fitted onto the guide shaft is fixedly installed inside the through hole 121 of the side arm 12. Since the direct fit between the guide shaft and the through hole of the side arm is prone to gaps due to machining errors or wear, this can cause radial displacement of the gripper during movement. Therefore, by filling the gap between the guide shaft and the through hole with the bushing, the guide shaft is prevented from wobbling during movement, ensuring that the guide shaft always moves stably along a preset horizontal direction, thereby improving guiding accuracy.

[0028] In this embodiment, bushing 122 is an oil-free bushing. Using an oil-free bushing eliminates the need for additional lubricating oil, thereby reducing wafer contamination.

[0029] In this embodiment, the connecting block 31 is an Invar steel connecting block. The support shaft 30 is an Invar steel support shaft. Because Invar steel has an extremely low coefficient of thermal expansion, this avoids temperature stress causing the spring preload to drift.

[0030] like Figure 1 As shown, in this embodiment, a base 9 is also provided below the base plate 10. A rotary motor 8 is fixed on the base 9. The base plate 10 is fixed to the output end of the rotary motor 8.

[0031] The above describes a collapsible gripper device according to this utility model. During operation, the wafer 6 is transferred between the two side arms via an external robotic arm. Subsequently, the drive mechanism 20 is activated, driving the two side arms to move synchronously towards each other. The grippers 13 on the side arms first contact and adhere to the edges of the wafer 6. Because the wafer 6 stops, the position of the grippers 13 remains unchanged, while the side arms 12 continue to move towards the wafer. During this process, the side arms 12 and the connecting block 31 compress the spring 32, causing it to elastically deform. The buffer area provides displacement space, jointly weakening the clamping impact force. At the same time, the free end of the guide shaft gradually approaches the contact sensor 38. When the free end of the guide shaft 33 touches the contact sensor 38, the contact sensor 38 sends a signal to the control system, and the drive mechanism immediately stops, completing the clamping of the wafer. The robotic arm releases the wafer. Afterward, according to the processing requirements, the rotary motor on the base is activated, and the motor output drives the base plate and the wafer clamped above to rotate. Once the wafer processing is complete, the robotic arm clamps the wafer 6, and the drive mechanism drives the two side arms to move away in opposite directions simultaneously. The compressed springs release their elastic potential energy, pushing the grippers and connecting blocks back to their initial positions, preparing for the clamping of the next wafer.

[0032] In summary, this invention utilizes the compression spring and buffer area in the collapsible structure. When the grippers contact the wafer and apply clamping force, the compression spring undergoes elastic deformation, effectively offsetting part of the clamping impact force transmitted by the grippers. This transforms the rigid contact force between the grippers and the wafer into a flexible buffer force. The buffer area provides displacement space for the grippers and connecting blocks, further weakening the impact force and preventing damage such as cracking or scratches caused by excessive clamping force directly squeezing the wafer. Secondly, through the cooperation of the guide shaft and the contact sensor, when the two side arms move synchronously towards each other until the grippers are in contact with the wafer, the free end of the guide shaft gradually approaches the contact sensor. When the free end of the guide shaft touches the contact sensor, the contact sensor can immediately provide a clamping signal, preventing the wafer from easily falling off due to excessively loose clamping or being damaged due to excessively tight clamping. Furthermore, the cooperation between the support shaft and the first and second through holes, as well as the cooperation between the guide shaft and the through hole, forms a double guiding structure, preventing the grippers from wobbling during wafer clamping. In addition, by adding disc springs, when the jaws clamp the wafer, the compression spring first offsets the initial clamping impact force through elastic deformation; if the clamping force continues to increase and causes the compression spring to compress to its limit position, the disc spring can immediately take on the buffering role and continue to provide flexible support through its own elastic deformation, avoiding the jaws from hard contacting the wafer after the compression spring reaches its limit, which would cause the wafer to break, thus improving the safety of wafer clamping.

[0033] The above description provides a detailed account of one embodiment of the present invention. However, this description is merely a preferred embodiment and should not be construed as limiting the scope of the present invention. All equivalent variations and improvements made within the scope of the claims of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A collapsible gripper device, comprising a pair of side arms disposed on the upper surface of a base plate, grippers disposed on the inner surfaces of each side arm, and a drive mechanism for driving the two side arms to move synchronously toward each other to cause the grippers to clamp a wafer; characterized in that, The gripper and the side arm have a collapsible structure, which includes a mounting groove on the inner side of the side arm. A connecting block connected to the gripper is provided in the mounting groove. A buffer area is formed between the connecting block and the mounting groove. A horizontal support shaft is connected in the gripper. A first through hole and a second through hole are respectively provided on the connecting block and the side arm at the position corresponding to the support shaft. The free end of the support shaft passes through the first through hole and the second through hole in sequence. A retaining spring is sleeved on the free end of the support shaft on the outside of the side arm. The second through hole is a stepped hole, divided into a coarse section and a fine section. A disc spring and a compression spring are provided in the coarse section and are sleeved on the support shaft in sequence. The disc spring contacts the connecting block. One end of the compression spring abuts against the bottom step of the coarse section and the other end abuts against the disc spring. A horizontal guide shaft is connected in the connecting block. A through hole is provided on the side arm at the position corresponding to the guide shaft. The free end of the guide shaft passes through the through hole. A contact sensor is provided on the outer side of the side arm at the position corresponding to the guide shaft.

2. The collapsible gripper device according to claim 1, characterized in that, The grippers are made of anti-static nylon material.

3. The collapsible gripper device according to claim 1, characterized in that, A bushing fitted onto the guide shaft is fixed inside the through hole of the side arm.

4. The collapsible gripper device according to claim 3, characterized in that, The bushing is an oil-free bushing.

5. The collapsible gripper device according to claim 1, characterized in that, The connecting block is an Invar connecting block, and the support shaft is an Invar support shaft.

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