Wafer transfer equipment capable of preventing scratch

Abstract

The invention relates to the technical field of semiconductor transfer devices, in particular to anti-scratch wafer transfer equipment, which comprises a machine body, a primary movement joint, an extension arm, a wafer taking fork hand, a first Bernoulli suction cup, a second Bernoulli suction cup and a positioning column. The first Bernoulli suction cup, the second Bernoulli suction cup and the positioning column are arranged, in the wafer suction process, the wafer is sucked through the first Bernoulli suction cup, the positioning column is sucked through the second Bernoulli suction cup, and due to the fact that the overshoot of the positioning column is configured to be the same as the overshoot of the wafer, the wafer can be sucked through the first Bernoulli suction cup and the positioning column; as the wafer is positioned by the positioning column at the moment, the wafer can be transferred to the required position of the next procedure in the process that the positioning column and the wafer fluctuate up and down at the same frequency, the transfer time can be saved, the transfer efficiency of the wafer can be improved, and the transfer efficiency of the wafer can be improved. In addition, the wafer can be prevented from axially sliding relative to the positioning column and being scratched.

Description

Technical Field

[0001] This invention relates to the field of semiconductor transfer device technology, and in particular to a wafer transfer device that prevents scratches. Background Technology

[0002] Specialized transfer devices—wafer handling robots—are required for the transfer of wafers between different processes. Most existing wafer handling robots are non-contact, and their main structure includes a robotic arm, handling fingers, a Bernoulli chuck, and positioning feet. The semi-circular arm is mounted on the robotic arm, the Bernoulli chuck is mounted on the handling fingers, and there are multiple positioning feet spaced apart on the handling fingers.

[0003] When handling wafers, the Bernoulli chuck blows out a high-pressure airflow, creating a negative pressure in the central area of ​​the chuck to attract the wafer closer to the chuck. At the same time, the high-pressure airflow flows out from the edge area of ​​the Bernoulli chuck, thus forming an "air mold" between the wafer and the Bernoulli chuck, thereby achieving non-contact handling of the wafer.

[0004] During the process of picking up a wafer, once the wafer moves to the stable gap, it will continue to move closer to the Bernoulli chuck due to inertia. After oscillating up and down near the stable gap for a period of time, it tends to stabilize. If the wafer is positioned by the positioning pins during the up and down oscillation, the wafer may be deformed or scratched. Therefore, the wafer is usually positioned by the positioning pins after its position tends to stabilize, resulting in low transfer efficiency. Summary of the Invention

[0005] Therefore, it is necessary to provide a wafer transfer device that prevents scratches and addresses the problems existing in current wafer transport equipment, thereby solving the problem of low transfer efficiency in existing wafer transfer devices.

[0006] The above objectives are achieved through the following technical solutions: A wafer transfer device designed to prevent scratches includes: body; The primary motion joint is located on the fuselage. The arm extends and rotates to the end of the primary motion joint furthest from the machine body; The fork is positioned at the end of the extended arm furthest from the primary joint. The first Bernoulli suction cup has multiple cups, spaced apart in the middle of the fork handle; There are multiple second Bernoulli suction cups, which are spaced apart and horizontally slidably positioned at the edge of the fork handle, and the multiple second Bernoulli suction cups can simultaneously move closer to or away from the center of the fork handle. There are multiple positioning posts, each corresponding to a different second Bernoulli chuck. The positioning posts are slidably connected to the second Bernoulli chucks on the same axis, and the overshoot of the positioning posts is configured to be the same as the overshoot of the wafer.

[0007] Preferably, the axial distance between the positioning post and the second Bernoulli suction cup is adjustable.

[0008] Preferably, an automatic adjustment component is provided between the positioning post and the second Bernoulli suction cup to adjust the axial distance between the positioning post and the second Bernoulli suction cup.

[0009] Preferably, the automatic adjustment assembly includes an internally threaded tube, a motor, a main shaft, and a screw. The internally threaded tube is coaxially mounted on the second Bernoulli suction cup. The motor is mounted on the upper end of the internally threaded tube. The main shaft is fixedly connected to the output shaft of the motor. The screw is threadedly connected inside the internally threaded tube and is sleeved outside the main shaft. The screw and the main shaft can rotate synchronously around the axis of the screw and slide relative to each other along the axis of the screw. A limit ring is provided at the lower end of the screw. The diameter of the limit ring is larger than the diameter of the internally threaded tube. A positioning pin is slidably connected to the outside of the internally threaded tube.

[0010] Preferably, it also includes a detector and a controller. The detector is located on the wafer pick-up fork and is used to detect the initial gap between the wafer and the first Bernoulli chuck, and to detect the initial gap between the positioning post and the second Bernoulli chuck. The controller is used to receive the initial gap between the wafer and the first Bernoulli chuck, and to calculate the overshoot of the wafer; Based on the fact that the overshoot of the wafer is equal to the overshoot of the positioning post, the initial gap between the positioning post and the second Bernoulli chuck is calculated and recorded as the target value. Finally, the motor is started to adjust the axial position of the positioning post. When the detector detects that the initial gap between the positioning post and the second Bernoulli suction cup is equal to the target value, the controller controls the motor to stop rotating.

[0011] Preferably, the detector includes a first distance sensor and a second distance sensor. The first distance sensor is located at the middle of the wafer pick-up fork and is used to detect the initial gap between the wafer and the first Bernoulli chuck. The second distance sensor is located at the edge of the wafer pick-up fork and is used to detect the initial gap between the positioning post and the second Bernoulli chuck.

[0012] Preferably, the positioning post is conical, and the diameter of the end of the positioning post facing the wafer is smaller than the diameter of the end facing away from the wafer.

[0013] Preferably, the fork handle is provided with a linear drive element, the drive end of which is connected to the outside of the second Bernoulli suction cup, for driving the second Bernoulli suction cup to slide horizontally, thereby moving closer to or away from the middle position of the fork handle.

[0014] Preferably, the slice fork is made of ceramic.

[0015] Preferably, the extension arm includes a first-level extension arm, a second-level extension arm, and a third-level extension arm. The first-level extension arm is mounted on the machine body via a first-level motion joint. A second-level motion joint is provided between the second-level extension arm and the first-level extension arm. A third-level motion joint is provided between the third-level extension arm and the second-level extension arm.

[0016] The beneficial effects of this invention are: This invention comprises a first Bernoulli chuck, a second Bernoulli chuck, and a positioning post. During wafer holding, the wafer is held by the first Bernoulli chuck, and the positioning post is held by the second Bernoulli chuck. Since the positioning post is configured so that its overshoot is the same as the wafer's overshoot, both maintain the same frequency of up-and-down fluctuations even under unstable air pressure. Because the wafer has already been positioned by the positioning post, it can be transferred to the required position for the next process during the up-and-down fluctuations of the positioning post and the wafer at the same frequency. This saves transfer time, improves wafer transfer efficiency, and also prevents the wafer from sliding axially relative to the positioning post and being scratched. Attached Figure Description

[0017] Figure 1 This is an overall schematic diagram of a wafer transfer device for preventing scratches according to the present invention; Figure 2 This is a perspective view of a wafer transfer device for preventing scratches according to the present invention; Figure 3 for Figure 2 A magnified schematic diagram of the structure at point A in the middle; Figure 4 This is a schematic diagram of the structure of the second Bernoulli chuck in a wafer transfer device for preventing scratches according to the present invention; Figure 5 for Figure 4 A sectional view; Figure 6 This is a schematic diagram of the structure of the first Bernoulli chuck in a wafer transfer device for preventing scratches according to the present invention; Figure 7 This is a comparative data table of different initial gaps and overshoot amounts for 120g wafers, 200g wafers, and positioning posts in a wafer transfer device for preventing scratches according to the present invention. Figure 8 This is a comparison curve of different initial gaps and overshoot amounts for 120g wafers, 200g wafers, and positioning posts in a wafer transfer device for preventing scratches according to the present invention.

[0018] in: 100. Fuselage; 210. Level 1 joint; 220. Level 2 joint; 230. Level 3 joint; 310. Level 1 extended arm; 320. Level 2 extended arm; 330. Level 3 extended arm; 400. Piece-retrieving fork; 410. Horizontal guide groove; 510. First Bernoulli suction cup; 511. Central column; 520. Second Bernoulli suction cup; 610. First distance sensor; 620. Second distance sensor; 700, Positioning pin; 710, Column body; 720, Extension ring; 800. Automatic adjustment component; 810. Internally threaded tube; 820. Motor; 830. Spindle; 840. Screw; 850. Limit ring. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0020] The component designations used in this document, such as "first" and "second," are merely for distinguishing the described objects and do not have any sequential or technical meaning. The terms "connection" and "linkage" used in this invention, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0021] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0022] like Figures 1 to 8As shown, a wafer transfer device designed to prevent scratches includes a body 100, a primary motion joint 210, an extension arm, a wafer picker fork 400, a first Bernoulli chuck 510, a second Bernoulli chuck 520, and a positioning post 700. The primary motion joint 210 is mounted on the body 100. The extension arm is rotatably connected to the end of the primary motion joint 210 away from the body 100. The wafer picker fork 400 is located at the end of the extension arm away from the primary motion joint 210. There are multiple first Bernoulli chucks 510, which are spaced apart at the wafer picker. At the center of the fork 400, there are multiple second Bernoulli chucks 520. These multiple second Bernoulli chucks 520 are spaced apart and horizontally slidably positioned at the edge of the fork 400. The multiple second Bernoulli chucks 520 can synchronously move closer to or further away from the center of the fork 400. There are multiple positioning posts 700, and each positioning post 700 corresponds one-to-one with a multiple second Bernoulli chuck 520. The positioning posts 700 and their corresponding second Bernoulli chucks 520 are coaxially slidably connected. The positioning posts 700 are configured such that their overshoot is the same as the overshoot of the wafer.

[0023] Regarding "overshoot," it should be noted that, taking the first Bernoulli chuck 510 as an example, when the first Bernoulli chuck 510 is activated, the airflow pressure in the edge region below it rises rapidly. The formation speed of the negative pressure zone in the central region below the first Bernoulli chuck 510 is faster than the gap adjustment speed, causing the adsorption force to exceed the wafer's gravity for a short period. At this time, the wafer is quickly attracted to the first Bernoulli chuck 510, making the actual suspension gap of the wafer smaller than the stable target gap. The maximum value of the gap deviation at this time is the overshoot. Because the airflow field is unstable at this time, the wafer will fluctuate up and down within a certain range in the vertical direction. After the airflow field stabilizes, the gap between the wafer and the first Bernoulli chuck 510 stabilizes to the target gap. Therefore, when the positioning post 700 is configured so that its overshoot is the same as the wafer's overshoot, the positioning post 700 can fluctuate up and down at the same frequency as the wafer, thus allowing the positioning post 700 to remain relatively stationary with the wafer.

[0024] Overshoot It is 100% certain that: Overshoot With damping ratio There exists a one-to-one correspondence; therefore, if two objects of different masses have the same overshoot, it is essentially because they have the same damping ratio. ; Combining the calculation formulas for system damping ratio and ripple frequency: System damping ratio ; Fluctuation frequency : Comprehensive derivation: By adaptively matching the airflow damping system c and the system stiffness k with the mass m, this can be achieved by adjusting the initial clearance, etc., so that: ; but: ; At this point, the oscillation period of the positioning post 700 and the wafer can be made the same. Furthermore, by making the initial phase of the positioning post 700 and the wafer the same (i.e. by adjusting the initial position of the positioning post 700 and the wafer), the two can achieve oscillation at the same frequency.

[0025] During wafer transfer, the operator activates the primary motion joint 210, which drives the extension arm to rotate. The extension arm then rotates the wafer pick-up fork 400 synchronously. When the wafer pick-up fork 400 is directly above the wafer, the operator moves the primary motion joint 210, causing the extension arm to move downwards a certain distance. This ensures that the lower surfaces of the multiple positioning posts 700 are below the upper surface of the uppermost wafer but above its lower surface. Next, the multiple second Bernoulli suction cups 520 synchronously approach the center of the wafer pick-up fork 400. Since the multiple positioning posts 700 correspond one-to-one with the multiple second Bernoulli suction cups 520 and are coaxially slidably connected, the synchronous approach of the multiple positioning posts 700 to the center of the wafer pick-up fork 400 achieves wafer centering and clamping. Next, the first Bernoulli chuck 510 and the second Bernoulli chuck 520 are activated simultaneously. Under the negative pressure suction generated in the central area below the first Bernoulli chuck 510, the wafer is quickly sucked towards the first Bernoulli chuck 510. At the same time, under the negative pressure suction generated in the central area below the second Bernoulli chuck 520, the positioning post 700 is quickly sucked towards the second Bernoulli chuck 520. Since the positioning post 700 is configured so that its overshoot is the same as the wafer's overshoot, the positioning post 700 and the wafer oscillate up and down at the same frequency. Since the wafer has been positioned by the positioning post 700, the wafer can be transferred to the required position for the next process during the up and down oscillation of the positioning post 700 and the wafer at the same frequency. Therefore, the transfer time can be saved and the wafer transfer efficiency can be improved.

[0026] Furthermore, a linear drive element is provided inside the tablet fork 400. The drive end of the linear drive element is connected to the outside of the second Bernoulli suction cup 520 to drive the second Bernoulli suction cup 520 to slide horizontally, thereby moving closer to or away from the middle position of the tablet fork 400. Specifically, a horizontal guide groove 410 is provided at a corresponding position on the lower surface of the tablet fork 400. The linear drive element can be an electric telescopic rod, which is installed in the horizontal guide groove 410. The axis of the electric telescopic rod coincides with the straight line of the length direction of the horizontal guide groove 410. The drive end of the electric telescopic rod is fixedly connected to the outside of the second Bernoulli suction cup 520, thereby driving the second Bernoulli suction cup 520 to slide along the length direction of the horizontal guide groove 410, thereby moving closer to or away from the middle position of the tablet fork 400.

[0027] Furthermore, the positioning post 700 is composed of a post body 710 and an extension ring 720. The extension ring 720 is located at the upper end of the post body 710, and the diameter of the extension ring 720 is larger than the diameter of the post body 710.

[0028] During wafer transfer, wafers of different qualities require different initial gaps to avoid wafer overshoot damage and ensure stable wafer levitation. When the initial gap between the wafer and the first Bernoulli chuck 510 changes, the overshoot also changes. At this point, the wafer's overshoot is no longer the same as the overshoot of the positioning post 700; that is, the wafer no longer fluctuates up and down at the same frequency as the positioning post 700. This causes relative sliding between the wafer and the positioning post 700, increasing the risk of scratches on the wafer surface. To solve this problem, in a further embodiment, such as... Figures 1-5 As shown, the axial distance between the positioning post 700 and the second Bernoulli suction cup 520 is adjustable.

[0029] Furthermore, the primary motion joint 210 consists of two cylinders: a rotary cylinder and a moving cylinder. The fixed end of the rotary cylinder is mounted on the machine body 100, and the driving end of the rotary cylinder is connected to the fixed end of the moving cylinder. The driving end of the moving cylinder is connected to the extension arm. Thus, the rotation of the extension arm is achieved through the rotary cylinder, and the up-and-down movement of the extension arm is achieved through the moving cylinder.

[0030] In a further embodiment, the circumferential distance between the positioning post 700 and the second Bernoulli chuck 520 is adjustable. Specifically, when the initial gap between the wafer and the first Bernoulli chuck 510 changes, the axial distance between the positioning post 700 and the second Bernoulli chuck 520 is adjusted accordingly, that is, the initial gap between the positioning post 700 and the second Bernoulli chuck 520 is changed, so as to ensure that the overshoot of the wafer and the overshoot of the positioning post 700 remain the same, thereby ensuring that the positioning post 700 can still fluctuate up and down at the same frequency as the wafer.

[0031] When the weight of the wafer to be transferred changes, the circumferential distance (i.e., the initial gap) between the wafer and the first Bernoulli chuck 510 needs to be adjusted accordingly to ensure that the negative pressure suction force of the first Bernoulli chuck 510 on the wafer is appropriate. After the initial gap between the wafer and the first Bernoulli chuck 510 is determined, the operator calculates the overshoot corresponding to the new wafer based on the new initial gap. To ensure that the wafer and the positioning post 700 can oscillate up and down at the same frequency, the overshoot of the wafer must be the same as the overshoot of the positioning post 700. Therefore, the target initial gap corresponding to the positioning post 700 is calculated in reverse based on the overshoot of the positioning post 700. Then, the axial position of the positioning post 700 relative to the second Bernoulli chuck 520 is adjusted so that the initial gap between the positioning post 700 and the second Bernoulli chuck 520 is equal to the target initial gap. This ensures that the positioning post 700 and the wafer oscillate up and down at the same frequency during the transfer process.

[0032] In a further embodiment, such as Figures 1-5 As shown, an automatic adjustment component 800 is provided between the positioning post 700 and the second Bernoulli suction cup 520 to adjust the axial distance between the positioning post 700 and the second Bernoulli suction cup 520.

[0033] Furthermore, the automatic adjustment assembly 800 includes an internally threaded tube 810, a motor 820, a main shaft 830, and a screw 840. The internally threaded tube 810 is coaxially mounted on the second Bernoulli suction cup 520. The motor 820 is mounted on the upper end of the internally threaded tube 810. The main shaft 830 is fixedly connected to the output shaft of the motor 820. The screw 840 is threadedly connected inside the internally threaded tube 810 and is sleeved outside the main shaft 830. The screw 840 and the main shaft 830 can rotate synchronously around the axis of the screw 840 and slide relative to each other along the axis of the screw 840. A limit ring 850 is provided at the lower end of the screw 840. The diameter of the limit ring 850 is larger than the diameter of the internally threaded tube 810. The positioning post 700 is slidably connected to the outside of the internally threaded tube 810.

[0034] In the initial state, the positioning post 700 moves downward along the internal thread tube 810 under its own gravity. Since the diameter of the limiting ring 850 is larger than the diameter of the internal thread tube 810, the positioning post 700 moves downward until its lower surface is flush with the upper surface of the limiting ring 850. At this time, the distance between the upper surface of the positioning post 700 and the second Bernoulli suction cup 520 is the initial gap.

[0035] When the mass of the wafer to be transferred decreases, the initial gap between the first Bernoulli chuck 510 and the wafer needs to be increased. Correspondingly, the initial gap between the positioning post 700 and the second Bernoulli chuck 520 also needs to be increased.

[0036] Specifically, the motor 820 is started, which drives the main shaft 830 to rotate clockwise. Since the screw 840 and the main shaft 830 can rotate synchronously around the axis of the screw 840 and slide relative to each other along the axis of the screw 840, the main shaft 830 drives the screw 840 to rotate synchronously. Since the screw 840 is threadedly connected to the internal threaded tube 810, the screw 840 rotates circumferentially around its axis while moving axially along its axis. Since the limiting ring 850 is located at the lower end of the screw 840, the limiting ring 850 moves downward synchronously with the screw 840. Since the lower surface of the positioning post 700 is flush with the upper surface of the limiting ring 850 at this time, after the limiting ring 850 moves downward with the screw 840, the distance between the upper surface of the positioning post 700 and the second Bernoulli suction cup 520 increases. When the distance between the upper surface of the positioning post 700 and the second Bernoulli suction cup 520 increases to be equal to the target initial gap, the motor 820 stops rotating. Conversely, when the mass of the wafer to be transferred increases, the motor 820 rotates counterclockwise to reduce the distance between the upper surface of the positioning post 700 and the second Bernoulli chuck 520 to be equal to the target initial gap.

[0037] It should also be noted that, in order for the screw 840 and the spindle 830 to rotate synchronously around the axis of the screw 840 and slide relative to each other along the axis of the screw 840, the screw 840 and the spindle 830 can be connected by a spline.

[0038] In a further embodiment, the scratch-preventing wafer transfer device further includes a detector and a controller. The detector is mounted on the wafer pick-up fork 400 and is used to detect the initial gap between the wafer and the first Bernoulli chuck 510, and the initial gap between the positioning post 700 and the second Bernoulli chuck 520. The controller receives the initial gap between the wafer and the first Bernoulli chuck 510, calculates the wafer overshoot, and calculates the initial gap between the positioning post 700 and the second Bernoulli chuck 520 based on the wafer overshoot being equal to the positioning post 700 overshoot. This initial gap is recorded as the target value. Finally, the controller starts the motor 820 to adjust the axial position of the positioning post 700. When the detector detects that the initial gap between the positioning post 700 and the second Bernoulli chuck 520 is equal to the target value, the controller stops the motor 820 from rotating.

[0039] During wafer transfer, the detector continuously monitors the initial gap between the wafer and the first Bernoulli chuck 510, and the initial gap between the primary positioning post 700 and the second Bernoulli chuck 520. When the quality of the wafer to be transferred changes, the controller controls the rotating arm to move vertically so that the distance between the first Bernoulli chuck 510 and the wafer equals the new initial gap. Next, the controller receives the initial gap value between the wafer and the first Bernoulli chuck 510, calculates the wafer overshoot, and then... Based on the fact that the overshoot of the wafer is equal to the overshoot of the positioning post 700, the initial gap between the positioning post 700 and the second Bernoulli chuck 520 is calculated and recorded as the target value. Finally, the controller controls the motor 820 to start, so as to adjust the axial position of the positioning post 700, that is, to adjust the distance between the upper surface of the positioning post 700 and the second Bernoulli chuck 520. When the distance between the upper surface of the positioning post 700 and the second Bernoulli chuck 520 is equal to the target value, the motor 820 stops rotating, and the adjustment is completed.

[0040] It should also be noted that, in order to obtain the correlation between the initial clearance of the positioning column 700 and the overshoot, a corresponding fitting curve should be obtained and input into the controller's control system, such as... Figures 7-8 As shown, using 120g wafers, 200g wafers, and 160g positioning posts 700 as test objects, the overshoot corresponding to initial gaps of 0.3mm, 0.4mm, 0.5mm, and 0.6mm was calculated respectively. Then, the corresponding reference curves were fitted, and the initial gap of the corresponding positioning post 700 was calculated based on the fitted curves. For example, when the weight of the wafer to be transferred changes from 120g to 200g, the controller controls the first-level motion joint 210 to move vertically until the initial gap between the wafer and the first Bernoulli chuck 510 is equal to 0.5mm. According to the fitting curve, the overshoot of the 200g wafer at the initial gap of 0.5mm is 0.088. Then, the overshoot of 0.088 is substituted into the fitting curve of the positioning post 700 to obtain the initial gap of the positioning post 700 at the overshoot of 0.088, which is recorded as the target value. Finally, the controller controls the motor 820 to start, so that the distance between the positioning post 700 and the second Bernoulli chuck 520 is equal to the target value.

[0041] It should also be noted that, such as Figure 6 As shown, a central column 511 is coaxially arranged inside the first Bernoulli suction cup 510. The diameter of the central column 511 is the same as the diameter of the internal threaded tube 810. This arrangement is to ensure that the output flow of the first Bernoulli suction cup 510 and the second Bernoulli suction cup 520 is the same.

[0042] Furthermore, such as Figures 2-3As shown, the detector includes a first distance sensor 610 and a second distance sensor 620. The first distance sensor 610 is located at the center of the wafer pick-up fork 400 and is used to detect the initial gap between the wafer and the first Bernoulli chuck 510. When the light emitted from the emitting end of the first distance sensor 610 is blocked by the wafer, the light is reflected to the receiving end of the first distance sensor 610 to detect the distance between the first distance sensor 610 and the wafer, and then the distance between the first Bernoulli chuck 510 and the wafer is calculated. The second distance sensor 620 is located at the edge of the wafer pick-up fork 400 and is used to detect the initial gap between the positioning post 700 and the second Bernoulli chuck 520. When the light emitted from the emitting end of the second distance sensor 620 is blocked by the extension ring 720, the light is reflected to the receiving end of the second distance sensor 620 to detect the distance between the second distance sensor 620 and the extension ring 720, and then the distance between the second Bernoulli chuck 520 and the extension ring 720 is calculated.

[0043] In a further embodiment, such as Figure 5 As shown, the positioning post 700 is conical, and the diameter of the end of the positioning post 700 facing the wafer is smaller than the diameter of the end facing away from the wafer. Specifically, the post 710 is conical.

[0044] This design is intended to reduce the contact area between the wafer and the pillar 710, thereby reducing the possibility of wafer damage.

[0045] In a further embodiment, such as Figures 1-2 As shown, the slice fork 400 is made of ceramic material, such as zirconia ceramic.

[0046] Zirconia ceramics have extremely high chemical stability and a non-porous surface, so they do not adsorb dust, moisture or process gases from the air, thus effectively preventing wafer contamination.

[0047] In a further embodiment, such as Figure 1 As shown, the extension arm includes a primary extension arm 310, a secondary extension arm 320, and a tertiary extension arm 330. The primary extension arm 310 is mounted on the body 100 via a primary motion joint 210. A secondary motion joint 220 is provided between the secondary extension arm 320 and the primary extension arm 310. The secondary motion joint 220 is a rotary joint composed of a rotary cylinder. The fixed end of the rotary cylinder is connected to the primary extension arm 310, and the driving end of the rotary cylinder is connected to the secondary extension arm 320. A tertiary motion joint 230 is provided between the tertiary extension arm 330 and the secondary extension arm 320. The tertiary motion joint 230 is a rotary joint composed of a rotary cylinder. The fixed end of the rotary cylinder is connected to the secondary extension arm 320, and the driving end of the rotary cylinder is connected to the tertiary extension arm 330.

[0048] A secondary motion joint 220 is set between the primary extension arm 310 and the secondary extension arm 320, and a tertiary motion joint 230 is set between the secondary extension arm 320 and the tertiary extension arm 330. This is to reduce the length of the movement path of the wafer picker fork 400, thereby accelerating the wafer transfer efficiency.

[0049] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0050] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A wafer transfer device to prevent scratches, characterized in that, include: body; The primary motion joint is located on the fuselage. The arm extends and rotates to the end of the primary motion joint furthest from the machine body; The fork is positioned at the end of the extended arm furthest from the primary joint. The first Bernoulli suction cup has multiple cups, spaced apart in the middle of the fork handle; There are multiple second Bernoulli suction cups, which are spaced apart and horizontally slidably positioned at the edge of the fork handle, and the multiple second Bernoulli suction cups can simultaneously move closer to or away from the center of the fork handle. There are multiple positioning posts, each corresponding to a different second Bernoulli chuck. The positioning posts are slidably connected to the second Bernoulli chucks on the same axis, and the overshoot of the positioning posts is configured to be the same as the overshoot of the wafer.

2. The wafer transfer device for preventing scratches according to claim 1, characterized in that, The axial distance between the positioning post and the second Bernoulli suction cup is adjustable.

3. The wafer transfer device for preventing scratches according to claim 2, characterized in that, An automatic adjustment assembly is provided between the positioning post and the second Bernoulli suction cup to adjust the axial distance between the positioning post and the second Bernoulli suction cup.

4. The wafer transfer device for preventing scratches according to claim 3, characterized in that, The automatic adjustment assembly includes an internally threaded tube, a motor, a main shaft, and a screw. The internally threaded tube is coaxially mounted on the second Bernoulli suction cup. The motor is mounted on the upper end of the internally threaded tube. The main shaft is fixedly connected to the output shaft of the motor. The screw is threadedly connected inside the internally threaded tube and is sleeved outside the main shaft. The screw and the main shaft can rotate synchronously around the axis of the screw and slide relative to each other along the axis of the screw. A limit ring is provided at the lower end of the screw. The diameter of the limit ring is larger than the diameter of the internally threaded tube. A positioning pin is slidably connected to the outside of the internally threaded tube.

5. A wafer transfer device for preventing scratches according to claim 4, characterized in that, It also includes a detector and a controller. The detector is located on the wafer pick-up fork and is used to detect the initial gap between the wafer and the first Bernoulli chuck, and to detect the initial gap between the positioning post and the second Bernoulli chuck. The controller is used to receive the initial gap between the wafer and the first Bernoulli chuck, and to calculate the overshoot of the wafer; Based on the fact that the overshoot of the wafer is equal to the overshoot of the positioning post, the initial gap between the positioning post and the second Bernoulli chuck is calculated and recorded as the target value. Finally, the motor is started to adjust the axial position of the positioning post. When the detector detects that the initial gap between the positioning post and the second Bernoulli suction cup is equal to the target value, the controller controls the motor to stop rotating.

6. A wafer transfer device for preventing scratches according to claim 5, characterized in that, The detector includes a first distance sensor and a second distance sensor. The first distance sensor is located at the middle of the wafer pick-up fork and is used to detect the initial gap between the wafer and the first Bernoulli chuck. The second distance sensor is located at the edge of the wafer pick-up fork and is used to detect the initial gap between the positioning post and the second Bernoulli chuck.

7. A wafer transfer device for preventing scratches according to claim 1 or 4, characterized in that, The positioning post is conical, and the diameter of the end of the positioning post facing the wafer is smaller than the diameter of the end facing away from the wafer.

8. A wafer transfer device for preventing scratches according to claim 1, characterized in that, The fork for picking up the tablets is equipped with a linear drive element. The drive end of the linear drive element is connected to the outside of the second Bernoulli suction cup, which is used to drive the second Bernoulli suction cup to slide horizontally, thereby moving closer to or away from the middle position of the fork for picking up the tablets.

9. A wafer transfer device for preventing scratches according to claim 1, characterized in that, The slice fork handle is made of ceramic.

10. A wafer transfer device for preventing scratches according to claim 1, characterized in that, The extension arm includes a primary extension arm, a secondary extension arm, and a tertiary extension arm. The primary extension arm is mounted on the body via a primary motion joint. The secondary extension arm is connected to the primary extension arm via a secondary motion joint. The tertiary extension arm is connected to the secondary extension arm via a tertiary motion joint.

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