Wax-free polishing and feeding equipment for wafer

Abstract

The invention relates to wafer wax-free polishing feeding equipment which comprises a connecting rod driven by driving equipment, the bottom end of the connecting rod is fixedly connected with a suction cup communicated with a negative pressure mechanism, and the surface of the suction cup is sleeved with a positioning mechanism used for positioning a wafer. According to the wafer wax-free polishing feeding equipment, through the innovative design of the positioning mechanism, the inclined plane at the tail end of the guide rod makes contact with the outer circle of a wafer firstly before the suction cup sucks the wafer, vertically-downward movement is converted into soft radial guide force, and the situation that after rigid impact is conducted, the wafer is not damaged is effectively avoided; an electric push rod drives a push plate and a push rod to push a tensioning wheel to move, and two groups of pull ropes are tensioned synchronously, so that four guide rods are symmetrically pulled to overcome the pulling force of a reset spring to approach the edge of the wafer until the wafer is tightly attached, and the centering correction of the wafer at any posture is automatically completed in the process. And the geometric center of the wafer is highly superposed with the negative pressure center of the sucker.

Description

Technical Field

[0001] This invention relates to the field of loading equipment technology, specifically to a wafer wax-free polishing loading equipment. Background Technology

[0002] In the field of precision semiconductor wafer fabrication, chemical mechanical polishing (CMP) is a key process step for obtaining ultra-flat, damage-free surfaces. "Wax-free polishing" technology abandons the traditional paraffin bonding method, requiring the loading equipment to precisely transfer the wafer from the cassette to the polishing carrier using non-contact or minimal contact force, while ensuring extremely high positioning accuracy (typically at the micrometer level). Achieving rapid, non-destructive, and adaptive wafer centering during this process is the core technical challenge restricting loading efficiency and yield.

[0003] Existing wafer loading equipment mostly employs machine vision-based pose correction or simple mechanical edge positioning. While vision positioning systems offer high accuracy, they are expensive, complex, and sensitive to optical conditions in clean environments, with response speed limited by image processing time. Traditional mechanical positioning methods, on the other hand, typically use rigid structures for their positioning claws or guide blocks, which can easily cause hard impacts or stress concentrations when contacting wafer edges, posing a risk of scratching wafer edges or introducing microcracks. Furthermore, most mechanical positioning mechanisms struggle to quickly adapt to wafers of different diameters (e.g., 6-inch, 8-inch, 12-inch), requiring machine downtime for adjustments or fixture replacements when changing wafer sizes, severely impacting the equipment's production flexibility and overall efficiency.

[0004] Therefore, there is an urgent need in this field for a wafer-free polishing and loading positioning device that is simple in structure, fast in positioning, causes zero damage to the wafer, and can adapt to different sizes, in order to meet the stringent requirements of high yield, high cycle time and high flexibility in high-end semiconductor manufacturing. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a wafer wax-free polishing and loading device, which solves the problems mentioned above.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: a wafer wax-free polishing and loading device, including a connecting rod driven by a driving device, the bottom end of the connecting rod being fixedly connected to a suction cup communicating with a negative pressure mechanism, the surface of the suction cup being sleeved with a positioning mechanism for positioning the wafer, the positioning mechanism including a ring fixed circumferentially to the side of the suction cup, and two sets of positioning elements symmetrically arranged along the center of the suction cup being provided above the ring; The positioning component includes two guide rods symmetrically arranged on both sides of a circular ring surface and a guide wheel assembly rotatably disposed within a groove on the circular ring surface. One end of each guide rod passes through the top of the ring and extends to the bottom of the ring. The inner cavity of the ring has a guide groove slidably connected to the guide rod. A sliding block, fixedly connected to the guide rod, is slidably connected to the inner cavity of the guide groove. A return spring is fixedly connected to the inner cavity of the guide groove, and the other end of the return spring is fixedly connected to one side of the sliding block. The two guide rods are connected by a pull rope, which is guided by the guide wheel assembly. A tensioning wheel is slidably connected to the inner cavity of the groove via a sliding groove. A push plate, pushed by an electric actuator, is slidably connected to the inner cavity of the groove, and one end of the push plate is fixed. The device is connected to a push rod that abuts against the side of the tensioning wheel. During use, the wafer is picked up and loaded using a suction cup. As the suction cup descends, the ring descends first, and the four guide rods below press against the side of the wafer. The electric push rod pushes the push plate to move, which in turn presses against the tensioning wheel, causing the two tensioning wheels to pull the rope. This, in turn, causes the two guide rods to move the sliding block within the guide groove, locking it around the wafer. The electric push rod then stops, and the wafer size is adjusted accordingly. The device continues to descend, picking up the wafer using the suction cup for loading. After loading is complete, wafers of the same size can be positioned and picked up using the suction cup, ensuring that they are picked up in the center of the suction cup. The device can also be quickly adjusted according to the size of the wafer.

[0007] As a further embodiment of the present invention: the guide wheel assembly includes two guide wheels disposed on the side of the guide groove to change the direction of the pull rope and two guide wheels disposed on both sides of the tension wheel to change the direction.

[0008] As a further aspect of the present invention: the four guide rods of the two sets of positioning mechanisms are symmetrically arranged below the suction cup.

[0009] As a further aspect of the present invention, the end of the guide rod is provided with a bevel. The bevel can reduce the impact when in contact with the wafer, thus providing effective protection.

[0010] As a further aspect of the present invention: the pull rope is a steel wire rope, which can effectively transmit the force, so that the two guide rods can move the same distance.

[0011] As a further aspect of the present invention: the two sets of positioning elements are symmetrically distributed along the suction cup at 225 degrees.

[0012] Compared with the prior art, the present invention has the following advantages: It achieves non-destructive, adaptive, and precise centering: Through an innovative positioning mechanism design, before the chuck picks up the wafer, the inclined surface at the end of the guide rod first contacts the outer circle of the wafer, converting the vertical downward motion into a gentle radial guiding force, effectively avoiding rigid impact. Subsequently, the push plate and push rod driven by the electric push rod push the tensioning wheel to move, simultaneously tensioning the two sets of pull ropes, thereby symmetrically pulling the four guide rods to overcome the tension of the return spring and move towards the edge of the wafer until they are in close contact. This process automatically completes the "centering" correction of the wafer in any position, ensuring that the geometric center of the wafer and the negative pressure center of the chuck are highly coincident, laying a solid foundation for subsequent precise placement.

[0013] It possesses excellent size compatibility and rapid changeover capability: The core transmission of the positioning mechanism is based on the cooperation of the pull rope and the tension wheel. By controlling the stroke of the electric push rod, the position of the tension wheel can be continuously adjusted, thereby changing the effective length of the pull rope and achieving adaptation to different shrinkage radii. One set of mechanisms can cover multiple wafer specifications within a certain size range. When changing products, there is no need to replace any mechanical parts. Only the program setting position of the electric push rod needs to be called or finely adjusted, and the size change can be completed in a very short time, which greatly improves the versatility and production flexibility of the equipment.

[0014] The synchronization and stability of the positioning process are ensured: steel wire rope is used as the pull rope, and its non-stretchable characteristics ensure that the force is transmitted without delay and without elastic deformation. When the tension wheel is pushed, it is guided by the symmetrically distributed guide wheel group, and the force is transmitted simultaneously and equally to the two symmetrically set guide rods, driving them to move synchronously and equidistantly towards the center. This forced synchronization mechanism eliminates the positioning eccentricity that may be caused by uneven friction, and ensures the repeatability and reliability of each positioning.

[0015] Compact structure, high reliability and easy maintenance: The entire positioning mechanism is integrated on the ring around the suction cup (integrated with the feeding spindle), requiring no additional space. Moving parts such as sliding blocks move in the guide groove, the guide rod is well supported and the movement is smooth. The main transmission components such as the pull rope, guide wheel, tension wheel, etc. are all standard parts or simple machined parts, with good durability and low maintenance cost. The return spring provides a reliable mechanism return force, ensuring that the guide rod can quickly return to the initial position after the tension is released, ready for the next work cycle. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a top view of the structure of the ring of the present invention; Figure 3 For the present invention Figure 2 A magnified view of a section at point A in the middle; Figure 4This is a bottom view of the structure of the ring of the present invention.

[0017] In the diagram: 1. Connecting rod; 2. Suction cup; 3. Ring; 4. Guide rod; 5. Inclined surface; 6. Guide groove; 7. Sliding block; 8. Return spring; 9. Pull rope; 10. Groove; 11. Push plate; 12. Push rod; 13. Tensioning wheel; 14. Slide groove. Detailed Implementation

[0018] 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.

[0019] Please see Figure 1-4 The present invention provides a technical solution: a wafer wax-free polishing and loading device, including a connecting rod 1 driven by a driving device, a suction cup 2 connected to a negative pressure mechanism at the bottom end of the connecting rod 1, a positioning mechanism for positioning the wafer on the surface of the suction cup 2, the positioning mechanism including a ring 3 fixed circumferentially on the side of the suction cup 2, and two sets of positioning elements symmetrically arranged along the center of the suction cup 2 above the ring 3. The positioning component includes two guide rods 4 symmetrically arranged on both sides of the surface of the ring 3 and a guide wheel assembly rotatably disposed within a groove 10 on the surface of the ring 3. One end of each guide rod 4 passes through the top of the ring 3 and extends to the bottom of the ring 3. A guide groove 6 is provided in the inner cavity of the ring 3, which is slidably connected to the guide rod 4. A sliding block 7 is slidably connected to the inner cavity of the guide groove 6 and fixedly connected to the guide rod 4. A return spring 8 is fixedly connected to the inner cavity of the guide groove 6, and the other end of the return spring 8 is fixedly connected to one side of the sliding block 7. The two guide rods 4 are connected by a pull rope 9, which is guided by the guide wheel assembly. A tension wheel 13 is slidably connected to the inner cavity of the groove 10 via a sliding groove 14. A push plate 11, which is pushed by an electric actuator, is slidably connected to the inner cavity of the groove 10. One end of the push plate 11 is fixedly connected to a tension wheel 13. The push rod 12, which abuts against the side of the tensioning wheel 13, is used to pick up and load the wafer via the suction cup 2. When the suction cup 2 descends, the ring 3 descends first, and the four guide rods 4 below press against the side of the wafer. The electric push rod pushes the push plate 11 to move, which in turn presses the tensioning wheel 13 via the push rod 12, causing the two tensioning wheels 13 to pull the pull rope 9 to move. This causes the two guide rods 4 to move the sliding block 7 within the guide groove 6, and then lock it around the wafer. The electric push rod then stops, and the wafer size is adjusted accordingly. The wafer continues to descend and is picked up by the suction cup 2 for loading. After loading is complete, wafers of the same size can be positioned and picked up by the suction cup 2. This ensures that the wafer is picked up at the center of the suction cup 2 and can be quickly adjusted according to the size of the wafer.

[0020] The guide wheel assembly includes two guide wheels located on the side of the guide groove 6 to change the direction of the pull rope 9, and two guide wheels located on both sides of the tension wheel 13 to change the direction.

[0021] The four guide rods 4 of the two positioning mechanisms are symmetrically arranged below the suction cup 2.

[0022] The end of the guide rod 4 is provided with a bevel 5. The bevel 5 can reduce the impact when in contact with the wafer, thus providing effective protection.

[0023] The pull rope 9 is a steel wire rope, which can effectively transmit the force, so that the two guide rods 4 can move the same distance.

[0024] The two sets of positioning components are symmetrically distributed along the suction cup at 2225 degrees.

[0025] In use, this invention operates on the principle of a synergistic process of first mechanical centering and then negative pressure adsorption. The specific steps are as follows: Phase 1: Descent and Initial Contact A drive device, such as a robotic arm or linear module, lowers the connecting rod 1 and the entire end effector, including the suction cup 2 and positioning mechanism, toward the wafer to be picked up. Before the bottom surface of the suction cup 2 contacts the wafer, the inclined surfaces 5 at the ends of the four guide rods 4, which are fixed below the ring 3 and are centrally symmetrically distributed, first contact the outer circumferential edge of the wafer. As the descent continues, the inclined surfaces 5 convert the vertical displacement into a radial guiding force, causing the wafer to slide slightly in the horizontal plane, initially correcting its positional deviation.

[0026] Phase Two: Active Tensioning and Precise Positioning Once the guide rod 4 is in contact with the wafer edge under the action of the inclined plane 5, the control system activates the electric actuator. The piston rod of the electric actuator extends, pushing the push plate 11 to slide within the groove 10. The push rod 12, fixed on the push plate 11, moves accordingly and presses the tension wheel 13 located in the slide groove 14, causing it to move towards the slack side of the pull rope 9. The displacement of the tension wheel 13 instantly tensions the pull rope 9 that passes over it. The pull rope 9 changes direction through the guide wheel assembly, with two symmetrical guide rods 4 connected to its two ends respectively. The tension of the pull rope 9 overcomes the pull of the return spring 8, and through the sliding block 7, drives the two guide rods 4 to move synchronously and smoothly along the guide groove 6 towards the center direction, i.e., the wafer edge, until all four guide rods 4 are tightly and evenly attached to the wafer perimeter with vertical surfaces, completing forced alignment and clamping positioning. The electric actuator then maintains its position and locks this state.

[0027] Phase 3: Negative Pressure Adsorption and Pickup After the wafer is precisely aligned and held in position by the four guide rods 4, the connecting rod 1 continues to descend slightly, bringing the sealing lip or porous surface of the chuck 2 into full contact with the back of the wafer. At this point, the negative pressure mechanism is activated, creating a vacuum inside the chuck 2, firmly adhering the wafer to the working surface of the chuck 2. Since positioning is complete, the center of the adsorbed wafer will inevitably coincide with the center of the chuck 2.

[0028] Phase Four: Enhancement, Transfer, and Release The drive unit lifts the connecting rod 1, and the wafer is safely picked up by the negative pressure adsorption of the suction cup 2, and transferred to the target station such as the polishing stage. After reaching the designated position, the negative pressure mechanism is closed, positive air pressure is introduced or the vacuum is directly broken, and the suction cup 2 releases the wafer and places it precisely.

[0029] Phase 5: Mechanism Reset After placement, the electric push rod retracts, releasing the pressure of the push plate 11 and push rod 12 on the tensioning wheel 13. At this time, under the restoring force of the return spring 8, each sliding block 7 drives the guide rod 4 to slide outward along the guide groove 6, returning to the initial open state, ready for the next loading cycle. The entire process is automatic and continuous, with high positioning accuracy and no physical damage to the wafer.

[0030] 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 wax-free polishing and loading device, comprising a connecting rod (1) driven by a driving device, wherein a suction cup (2) communicating with a negative pressure mechanism is fixedly connected to the bottom end of the connecting rod (1), and a positioning mechanism for positioning the wafer is sleeved on the surface of the suction cup (2), characterized in that: The positioning mechanism includes a ring (3) fixed circumferentially to the side of the suction cup (2), and two sets of positioning elements are provided above the ring (3) symmetrically arranged along the center of the suction cup (2); The positioning component includes two guide rods (4) symmetrically arranged on both sides of the surface of the ring (3) and a guide wheel assembly rotatably arranged in a groove (10) on the surface of the ring (3). One end of the guide rod (4) passes through the top of the ring (3) and extends to the bottom of the ring (3). The inner cavity of the ring (3) is provided with a guide groove (6) that is slidably connected to the guide rod (4). The inner cavity of the guide groove (6) is slidably connected to a sliding block (7) that is fixedly connected to the guide rod (4). The inner cavity of the guide groove (6) is fixedly connected to a composite... The other end of the return spring (8) is fixedly connected to one side of the sliding block (7). The two guide rods (4) are connected by a pull rope (9). The pull rope (9) is guided by the guide wheel group. The inner cavity of the groove (10) is slidably connected to the tension wheel (13) through the slide groove (14). The inner cavity of the groove (10) is slidably connected to the push plate (11) pushed by the electric push rod. One end of the push plate (11) is fixedly connected to the push rod (12) that abuts against the side of the tension wheel (13).

2. The wafer wax-free polishing and feeding equipment according to claim 1, characterized in that: The guide wheel assembly includes two guide wheels located on the side of the guide groove (6) to change the direction of the pull rope (9) and two guide wheels located on both sides of the tension wheel (13) to change the direction.

3. The wafer wax-free polishing and feeding equipment according to claim 1, characterized in that: The four guide rods (4) of the two sets of positioning mechanisms are symmetrically arranged below the suction cup (2).

4. The wafer wax-free polishing and feeding equipment according to claim 1, characterized in that: The guide rod (4) has an inclined surface (5) at its end.

5. The wafer wax-free polishing and feeding equipment according to claim 1, characterized in that: The pull rope (9) is a steel wire rope.

6. The wafer wax-free polishing and feeding equipment according to claim 1, characterized in that: The two sets of positioning components are symmetrically distributed along the suction cup (2) at 225 degrees.

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