Wafer centering and positioning device, transmission device, thinning equipment and centering method

Abstract

The invention relates to a wafer centering and positioning device, a transmission device, thinning equipment and a centering method. The wafer centering and positioning device comprises a rack which comprises a base and a stand column; the motor bracket is mounted on the base and is provided with a leveling bolt; the top of the driving motor is fixed to the top of the motor support, the bottom of the driving motor is suspended, and the leveling bolt is configured to adjust the levelness of the motor support relative to the base so as to adjust the levelness of the driving motor; the centering base disc is provided with linear guide rails which are distributed in the circumferential direction with the centering center of the wafer as the circle center and extend in the radial direction; the centering rotating disc is arranged below the centering base disc and can rotate relative to the centering base disc, the rotating center of the centering rotating disc is aligned with the centering center of the wafer, and the centering rotating disc is provided with an involute spiral guide rail; and the centering stop block is provided with stop columns, the centering stop block can slide along the involute spiral guide rail and the linear guide rail at the same time, and the center distances from the stop columns to the rotation center are identical at all circumferential angles of the centering rotary disc.

Description

[0001] This application is a divisional of the invention patent application with the application number 202411843417.4 and the title "Wafer Centering and Positioning Device, Transfer Device, Thinning Equipment and Centering Method", which was filed on December 14, 2024. Technical Field

[0002] The present invention relates to the field of semiconductor manufacturing technology; more specifically, the present invention relates to a wafer centering and positioning device, a wafer transfer device, a wafer thinning equipment and a wafer centering method. Background Art

[0003] In the manufacturing process of semiconductor special equipment, realizing automatic wafer center positioning is a key technology.

[0004] In modern production equipment, common positioning methods for wafer center positioning devices include V-shaped center positioning, rotary center positioning, etc. Among them: V-shaped center positioning has high requirements for the surface roughness of V-shaped parts and great processing difficulty; the rotary center positioning device has a complex structure, difficult rotation control, and difficult-to-control problems, and it is difficult to guarantee the accuracy, which further leads to troublesome operations for wafer center positioning. Summary of the Invention

[0005] In view of this, the present application provides a wafer centering and positioning device, a wafer transfer device, a wafer thinning equipment and a wafer centering method, thereby solving or at least alleviating one or more of the above problems and other problems existing in the prior art.

[0006] To achieve the foregoing objectives, the first aspect of the present application provides a wafer centering and positioning device, wherein the wafer centering and positioning device includes:

[0007] A frame, including a base and at least three columns evenly distributed on the base;

[0008] A motor bracket, which is installed on the base, the columns are distributed on the outer periphery of the motor bracket, and leveling bolts are provided at the bottom periphery of the motor bracket;

[0009] A driving motor, the top of which is fixed to the top of the motor bracket and the bottom of the driving motor is suspended, and the leveling bolts are configured to adjust the levelness of the motor bracket relative to the base to adjust the level of the driving motor;

[0010] A centering base plate, which is fixed to the base through the columns, the centering base plate provides a wafer centering center, and the centering base plate is provided with N linear guide rails distributed circumferentially and extending radially with the wafer centering center as the center of the circle, N≥3;

[0011] A centering turntable is provided below the centering base plate and is driven by the drive motor to rotate relative to the centering base plate. The rotation center of the centering turntable aligns with the wafer centering center, and the centering turntable is provided with an involute spiral guide rail; and

[0012] N centering stoppers, each centering stopper is provided with a retaining post protruding from the top surface of the centering base plate. The N centering stoppers are slidably mounted on the involute spiral guide rail and are respectively slidably mounted on the N linear guide rails. When the centering turntable rotates relative to the centering base plate around the rotation center, the centering stoppers can slide along the involute spiral guide rail and the linear guide rails simultaneously, and at each circumferential angle of the centering turntable, the center distance from each retaining post to the rotation center is always equal, which is used to push the wafer to the centering position.

[0013] In the wafer centering and positioning device as described above, optionally, the drive motor is configured to reversely drive the centering turntable so that the retaining posts of the centering stoppers retreat to create a space for placing the wafer on the centering base plate, and after the wafer to be centered is placed in position, the drive motor is configured to forwardly drive the centering turntable to tighten the centering stoppers for centering operation.

[0014] In the wafer centering and positioning device as described above, optionally, the N linear guide rails are circumferentially evenly distributed with the wafer centering center as the center of the circle.

[0015] In the wafer centering and positioning device as described above, optionally, the centering base plate is provided with a vacuum chuck at the wafer centering center for adsorbing and fixing the centered wafer, and the top plane of the vacuum chuck protrudes from the top surface of the centering base plate.

[0016] In the wafer centering and positioning device as described above, optionally, each centering stopper is provided with a pair of juxtaposed retaining posts, and the distance between the retaining posts is greater than the opening length of the notch of the wafer.

[0017] In the wafer centering and positioning device as described above, optionally, the involute spiral guide rail is a spiral groove, the linear guide rail is a guide shaft, a radially penetrating radial groove is opened in the centering base plate, the guide shaft is fixed in the radial groove, the bottom of the centering stopper has a convex portion adapted to extend into the spiral groove to slide along the spiral groove, and the centering stopper is sleeved on the guide shaft and is located in the radial groove.

[0018] In the wafer centering and positioning device as described above, optionally, both ends of the guide shaft are fixed to the centering base plate by set screws.

[0019] In the wafer centering and positioning device as described above, optionally, the centering stopper is mounted on the guide shaft through a linear bearing.

[0020] In the wafer centering and positioning device as described above, optionally, the involute spiral guide rail is an equidistant spiral guide rail, and at each rotation angle of the centering turntable, the center distance increment of the equidistant spiral guide rail is equal.

[0021] In the wafer centering and positioning device as described above, optionally, the position of the stop post on the centering stopper is set such that when the centering stopper is mounted on the wafer centering and positioning device, the distance from the stop post on each centering stopper to the wafer centering center is the same.

[0022] In the wafer centering and positioning device as described above, optionally, the stop post is set to be radially movable and adjustable, and a stop post position radial adjustment mechanism is provided on the centering stopper. The stop post position radial adjustment mechanism is set with adjustment calibration positions according to the interval angles of the respective centering stoppers for adjusting and compensating the radial displacement difference of the stop post.

[0023] In the wafer centering and positioning device as described above, optionally, the centering turntable is provided with N involute spiral guide rails, the involute spiral guide rails have the same size and shape and are evenly arranged in circumferential indexing. Each centering stopper is respectively mounted on a different involute spiral guide rail, and the centering stoppers are evenly distributed in the circumferential direction.

[0024] In the wafer centering and positioning device as described above, optionally, the centering base plate is located at the top of the wafer centering and positioning device.

[0025] In the wafer centering and positioning device as described above, optionally, a sensor is provided on the centering base plate. The sensor is used to identify the size of the wafer. And the wafer centering and positioning device is configured such that after the sensor identifies the size of the wafer, it controls the drive motor to drive the centering stopper to move away from the wafer centering center to yield a space for placing the wafer. After the wafer to be centered is in place, it drives the centering stopper to move towards the wafer centering center to perform a centering action.

[0026] To achieve the foregoing object, a second aspect of the present invention provides a wafer transfer device, wherein the wafer transfer device includes the wafer centering and positioning device as described in any one of the foregoing first aspects and a moving mechanism. The wafer centering and positioning device is used to adjust the position of the wafer, and the wafer centering and positioning device is connected to the moving mechanism so that the moving mechanism drives the wafer centering and positioning device to move.

[0027] To achieve the foregoing objectives, a third aspect of the present invention provides a wafer thinning device, wherein the wafer thinning device includes:

[0028] A front-end module, which is located at the front end of the wafer thinning device and is used to realize the loading and unloading of wafers;

[0029] A grinding module, which is located at the end of the wafer thinning device and is used for grinding the wafer;

[0030] A polishing module, which is located between the front-end module and the grinding module and is used for chemical mechanical polishing of the wafer; and

[0031] The wafer transfer device as described in the foregoing second aspect, which is parallel to the polishing module and is located between the front-end module and the grinding module.

[0032] To achieve the foregoing objectives, a fourth aspect of the present invention provides a wafer centering method using the wafer centering and positioning device as described in any one of the foregoing first aspects, wherein the method includes the following steps:

[0033] The retaining posts create a wafer receiving space according to the size of the wafer;

[0034] Receive the wafer on the vacuum chuck on the centering base plate;

[0035] Control the movement of the stopper so that the retaining posts push the wafer to be centered; and

[0036] Stop centering when the pushing action of the retaining posts reaches the size of the wafer.

[0037] The present invention provides a wafer centering and positioning device, a wafer transfer device, a wafer thinning device, and a wafer centering method, which can achieve the center positioning of wafers of different sizes, and are overall simple, operate stably, and have high repeat positioning accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] With reference to the accompanying drawings, the disclosure of the present invention will become more apparent. It should be understood that these drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present invention. In the drawings:

[0039] Figure 1 is a schematic perspective view of an embodiment of the wafer centering and positioning device according to the present invention;

[0040] Figure 2 is Figure 1 a schematic detailed perspective view of the centering turntable of the wafer centering and positioning device in, in which a vacuum chuck, a guide shaft, and a centering stopper are also shown;

[0041] Figure 3 is Figure 1 a schematic perspective view of another angle of the wafer centering and positioning device in;

[0042] Figure 4 is Figure 1 A schematic perspective view of the centering stopper of the wafer centering and positioning device in

[0043] Figure 5 is Figure 1 A schematic installation view of the centering stopper of the wafer centering and positioning device on the guide shaft in

[0044] Figure 6 Schematically shows Figure 5 The linear bearing between the centering stopper and the guide shaft in

[0045] Figure 7 Schematically shows Figure 5 The installation view of the guide shaft on the centering base plate in ; and

[0046] Figure 8 Schematically shows a perspective view of an embodiment of the wafer thinning equipment of the present invention, which simultaneously shows the wafer transfer device.

[0047] Reference numerals: 1 - wafer centering and positioning device; 2 - centering base plate; 3 - wafer centering center; 4 - top surface; 5 - linear guide rail; 6 - centering turntable; 7 - involute spiral guide rail; 8 - centering stopper; 9 - stop post; 10 - frame; 11 - drive motor; 12 - base; 13 - column; 14 - motor bracket; 15 - leveling bolt; 16 - vacuum chuck; 17 - radial groove; 18 - protrusion; 19 - setscrew; 20 - linear bearing; 23 - sensor; 30 - wafer; 31 - grinding module; 32 - third manipulator; 33 - second position; 34 - wafer transfer device; 35 - first position; 36 - second manipulator; 37 - buffer module; 38 - front end module; 39 - first manipulator; 40 - processing unit; 41 - polishing module; 42 - grinding workbench. Detailed implementation manners

[0048] Referring to the accompanying drawings and specific embodiments, the structures, compositions, features, advantages, etc. of the wafer centering and positioning device, wafer transfer device, wafer thinning equipment and wafer centering method of the present invention will be described by way of example below. However, all descriptions should not form any limitation to the present invention.

[0049] For any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature shown or implied in the respective drawings, the present invention still allows any combination or deletion to continue between these technical features (or their equivalents) without any technical obstacles. Therefore, it should be considered that these more embodiments according to the present invention are also within the scope of the present disclosure.

[0050] Furthermore, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature.

[0051] Figure 1 is a schematic perspective view of an embodiment of a wafer alignment and positioning device according to the present invention.

[0052] As shown in the figure, in this embodiment, the wafer alignment and positioning device 1 may include an alignment base plate 2, a frame 10, and an alignment turntable 6 as shown in Figure 2 the figure. The alignment base plate 2 is fixed on the frame 10. When the wafer alignment and positioning device 1 is operating, the alignment turntable 6 rotates relative to the alignment base plate 2, and the alignment stopper 8 is under the combined action of the spiral guide rail 7 on the alignment turntable 6 as shown in Figure 2 the figure and the linear guide rail 5 on the alignment base plate 2 as shown in Figure 1 the figure. The alignment stopper 8 drives the stopper post 9 to push the wafer to be aligned (not shown) at various angles, thereby achieving the alignment of the wafer. After the alignment is completed, the vacuum chuck 16 adsorbs the wafer and fixes it in place for subsequent operations.

[0053] As can be seen from the figure, in this example, the alignment base plate 2 is circular and provides a wafer alignment center 3. In other embodiments, other shapes of the alignment base plate may also be used. The alignment center 3 may be aligned with the center of the vacuum chuck 16 and may also be aligned with the rotation center of the alignment turntable 6.

[0054] In this example, the alignment base plate 2 is located at the top of the wafer alignment and positioning device 1, providing more operating space, facilitating the picking and placing of the wafer by a manipulator, etc., and also facilitating possible grinding, polishing, etc.

[0055] The alignment base plate 2 is provided with N linear guide rails 5 that are circumferentially distributed around the wafer alignment center 3 and extend radially. These linear guide rails 5 may be evenly distributed. In the illustrated example, N = 3. It can be understood that in alternative embodiments, N ≥ 3 may be set; for example, 3 of them may be selected as the main alignment stoppers for the linear guide rail installation, and the others may be used for installing auxiliary alignment stoppers to facilitate improving the alignment efficiency and alignment accuracy. It can also be clearly seen from the figure that the linear guide rail 5 is located in the radially penetrating radial groove 17, so that the stopper post 9 on the alignment stopper 8 can protrude from the top surface of the alignment base plate 2. In some embodiments, it may also be arranged such that the alignment stopper 8 is not within the radial groove 17, but only the stopper post 9 passes through these radial grooves 17.

[0056] Corresponding to the N linear guide rails 5, N centering blocks 8 can be provided in the wafer centering and positioning device. In the illustrated example, there are 3 centering blocks 8. As can be seen from the figure, each centering block 8 is provided with a retaining post 9 that protrudes from the top surface 4 of the centering base plate 2. Optionally, a pair of juxtaposed retaining posts 9 can be provided on each centering block 8, and the distance between the pair of retaining posts 9 is greater than the opening length of the notch of the wafer. If only a single retaining post 9 is provided, there is a risk that the wafer cannot be clamped or is not clamped in place if the notch of the wafer abuts against the retaining post 9. Setting two paired retaining posts 9 in this way can avoid this situation. Even if one of the retaining posts 9 is abutted by the notch of the wafer, the other of the retaining posts 9 can still play a centering role.

[0057] The linear guide rails 5 in the figure are all located radially on the radial direction of the centering base plate 2, towards the centering center on the centering base plate 2. The radial groove 17 faces the same direction as the linear guide rail 5.

[0058] According to the illustrated example, the centering block 8 is slidably mounted on the involute spiral guide rail 7 (see Figure 2 ) and is slidably mounted on the same number of linear guide rails 5 respectively. When the centering turntable 6 rotates around the rotation center relative to the centering base plate 2, the centering block 8 can slide along the involute spiral guide rail 7 and the linear guide rail 5 simultaneously, so that the retaining post 9 pushes the wafer to be centered.

[0059] The figure also shows the frame 10 and the drive motor 11 of the wafer centering and positioning device 1. The frame 10 is used to provide support for the wafer centering and positioning device 1 and place the wafer centering and positioning device 1 in an appropriate position, such as but not limited to being placed on the ground, being placed in a wafer thinning and polishing integrated machine, etc. The centering base plate 2 and the drive motor 11 can be mounted on the frame 1, and the centering base plate 2 and the drive motor 11 can be fixed relative to the frame. The drive motor 11 is used to drive the centering turntable 6 to rotate around the rotation center.

[0060] The frame 10 includes a base 12 and columns 13. The base 12 shown in the figure is circular, and the columns 13 are evenly distributed on the circumference of the base 13. Three columns are shown in the figure. In other embodiments, different numbers such as four or more are also possible. The centering base plate 2 is fixed to the base 12 through the columns 13. As can be seen from the figure, the frame 10 further includes a motor support 14. In this example, the motor support 14 includes four columns. The motor support 14 is installed on the base 12 and is located within the inner circumference enclosed by the columns 13. The drive motor 11 is fixed to the motor support 14, specifically inside it. The columns 13 are distributed on the outer circumference of the motor support 14. Leveling bolts 15 are provided at the bottom peripheral edge of the motor support 14 for adjusting the level of the motor relative to the base 12 through the motor support 14 to ensure centering accuracy. To effectively level, the drive motor 11 can be installed at the top of the motor support 14 at the top, and the bottom of the drive motor can be suspended, so that no additional constraint is formed at the bottom of the drive motor 11 during leveling.

[0061] The centering base plate 2 is provided with a vacuum chuck 16 at the wafer centering center 3 for adsorbing and fixing the centered wafer. Although the illustrated vacuum chuck 16 is circular, it is not limited to this in alternative embodiments and can be square or other polygons, etc. The vacuum chuck 16 has air holes for evacuating, shown in the figure in the form of circles or slots along the diameter direction. If it is necessary to determine the wafer position with the vacuum chuck in some embodiments, the vacuum chuck can be higher than the top surface 4 and protrude.

[0062] The position of the stop post 9 on the centering block 8 is set such that when the centering block 8 is installed on the wafer centering and positioning device 1, the distance from each stop post 9 on each centering block 8 to the wafer centering center 3 is the same. Such a setting makes the distances from the edges of the wafer pushed by the respective centering stop posts 9 to the wafer centering center at various angles the same, that is, the center of the wafer is aligned with the centering center of the centering base plate 2. After the wafer is pushed to the centering position by the stop post 9, the vacuum chuck 16 adsorbs the wafer and fixes it in place.

[0063] Further, in the illustrated example, a sensor 23 is also provided on the centering base plate 2. The sensor 23 can be used to identify the size of the wafer. At this time, the wafer centering and positioning device 1 can be set such that after the sensor 23 identifies the size of the wafer, such as an 8-inch wafer or a 12-inch wafer, it feedback-controls the drive motor 11 to reversely drive the centering turntable 6 so that the stop posts 9 of the centering blocks 8 retreat on the centering base plate 2 to create a space for placing the wafer. After the base circle to be centered is placed in position, according to the size information of the wafer, the drive motor 11 is driven forward to rotate the centering turntable 6 towards the center to tighten the centering blocks 8 for centering action. The retreat of the stop posts 9 can advantageously prevent misplacement and uneven placement of the wafer during placement and perform centering according to the specific wafer size, preventing centering failure, fragmentation, wafer slippage, etc. caused by insufficient centering or over-centering.

[0064] In an alternative embodiment, the sensor 23 may also be omitted. In this case, after each wafer alignment operation is completed and before the next alignment operation is performed, the alignment stopper 8 can drive the stopper post 9 to retract once to provide sufficient accommodation space for the wafer.

[0065] Figure 2 is Figure 1 A schematic detailed perspective view of the alignment turntable of the wafer alignment and positioning device, in which a vacuum chuck, a guide shaft, and an alignment stopper are also shown.

[0066] As shown in the figure, in this example, the alignment turntable 6 is generally circular. In alternative embodiments, other suitable shapes may also be selected. On the alignment turntable 6, a grooved involute spiral guide rail 7, an alignment stopper 8 engaged therewith and sleeved on the linear guide rail 5, and a vacuum chuck 16 aligned with the rotation center of the alignment turntable 6 are shown. In alternative embodiments, the involute spiral guide rail 7 may also be a spiral rod-shaped guide rail, a convex spiral guide rail, etc. Correspondingly, the alignment stopper 8 may be designed with a complementary-shaped structure. When the alignment turntable 6 rotates, since the alignment stopper 8 engages with the linear guide rail of the alignment base plate 2, it does not change its angular position with the rotation of the alignment turntable 6, but makes a synchronous radial movement along the linear guide rail 5 to align the wafer. This alignment method advantageously reduces the control difficulty of the wafer center positioning device, makes its structure simple and the positioning accuracy high, and the device has the advantages of stable operation and convenient use.

[0067] In one embodiment of the present invention, by the rotation of the alignment turntable having an equal pitch spiral groove, the embedded alignment stopper cooperating with the spiral groove contracts or expands towards the center under the action of the guide shaft. Since the distances from different positions of the spiral groove to the center of the turntable are different, in order to achieve the alignment function, it is also necessary to control the different positions of the two stoppers above the alignment stopper on the alignment stopper, and finally make the distances between the stoppers on the stopper and the center of the turntable all the same.

[0068] Specifically locally, in this example, the involute spiral guide rail 7 is an equidistant spiral guide rail. As can be seen from the figure, at each rotation angle of the centering turntable 6, the center distance increment of the equidistant spiral guide rail is equal. In this case, at different angles of the centering turntable 6, the distances from the spiral guide rail 7 at each position to the rotation center are not the same; in order to compensate for these distance differences, it can be designed such that the positions of each pair of stoppers 9 on the corresponding centering blocks 8 are not the same. Specifically, taking the position of the stopper 9 on one of the centering blocks 8 as a reference, the stoppers on the centering blocks closer to the center position are shifted outward for compensation, and the stoppers on the centering blocks farther from the center position are shifted inward for compensation, so that the stoppers on each group of centering blocks are always at the same distance from the center position, enabling the centering operation of the wafer to be completed by rotating the centering turntable 2.

[0069] The radial positions of the stoppers 9 on each block 8 can be fixed according to the compensation distance during manufacturing. This compensation distance is calculated based on the circumferential interval angle between the blocks 8 and the radial increment of the involute spiral guide rail 7 with the circumferential angle, to ensure that the distances from the stoppers 9 on each block 8 to the wafer centering center 3 are equal. Or the stopper 9 can be set to be radially movable and adjustable, for example, setting the adjustment scale position according to the interval angle. For the mass production of the centering blocks 8, so that each centering block 8 can be applied to each linear guide rail 5, it can be set such that the stopper 9 is adjustable in position along the direction of the linear guide rail 5 on the centering block 8. In this way, the adjustment of the stopper 9 can compensate for the different distances of the spiral guide rail from the center position at different phases. For example, the stopper 9 can be adjusted steplessly or in increments in position on the centering block 8. For incremental adjustment, scales can also be marked on the centering block 8 for aligning the compensation position according to the compensation amount required at different phases.

[0070] In an alternative embodiment, a radial adjustment mechanism for the stopper position can be provided on the centering block 8. The radial adjustment mechanism for the stopper position can be set with an adjustment scale position according to the interval angle of each centering block 8 as described above, for adjusting the radial displacement difference of the compensation stopper 9.

[0071] Combined Figure 2 and Figure 1 It can be understood that in the assembled wafer centering and positioning device 1, the centering turntable 6 is arranged below the centering base plate 2 and can rotate relative to the centering base plate 2. The rotation center of the centering turntable 6 is aligned with the wafer centering center 3. The centering turntable 6 is provided with an involute spiral guide rail 7. The centering blocks 8 are pushed by the spiral guide rail 7 to move radially along the linear guide rail 5 to achieve wafer centering. In the illustrated embodiment, at each circumferential angle of the centering turntable 6, the center distance from each stopper 9 to the rotation center is always equal, for pushing the wafer to the centering position. Here, the involute spiral guide rail 7 is a spiral groove, and the linear guide rail 5 is a guide shaft.

[0072] In other embodiments, the involute spiral guide rail 7 is not limited to the equidistant spiral guide rail shown in the figure. For example, the number of spiral guide rails can be set to be the same as the number of centering blocks 8, and the involute trajectories of each spiral guide rail are the same, but they can be in different phases that are equidistant along the circumferential direction with respect to the central position. Thus, when the centering turntable rotates, the centering blocks on each spiral guide rail move synchronously and the distances from the central position are always equal. That is, the centering turntable 6 can be provided with N involute spiral guide rails 7, the involute spiral guide rails have the same size and shape and are evenly distributed in the circumferential direction. Each centering block 8 is respectively installed on a different involute spiral guide rail 7, and the centering blocks 8 are evenly distributed along the circumferential direction. The advantage of such a setting is that the design of the stop post 9 can be simplified, and it is not necessary to adjust the positions of the stop posts on each centering block 8.

[0073] Figure 3 Yes Figure 1 It is a schematic perspective view of another angle of the wafer centering and positioning device. The centering base plate 2, the centering turntable 6, the upright column 13 in the frame 10, the motor bracket 14, etc. are shown in the figure.

[0074] This figure is from the perspective of observing from below the centering base plate 2 and the centering turntable 6, and shows the relative positional relationship between the centering base plate 2 and the centering turntable 6. The centering base plate 2 and the centering turntable 6 are not connected to each other. Therefore, while the centering base plate 2 remains stationary, the centering turntable 6 can rotate relative to the centering base plate 2 under the drive of the drive motor 11. As described above in combination with Figure 1 And Figure 2 When the centering turntable 6 rotates relative to the centering base plate 2, the involute spiral guide rail 7 will push each centering block 8 to slide along the linear guide rail 5 towards the central position, and the wafer is centered by the stop post 9 pushing the wafer.

[0075] The figure also partially shows the radial grooves, linear guide rails and motor brackets on the centering base plate 2. Combining Figure 1 、 Figure 2 And the corresponding descriptions can more clearly understand the working principles and functions of these features, and will not be elaborated here.

[0076] Figure 4 Yes Figure 1 It is a schematic perspective view of the centering block of the wafer centering and positioning device in

[0077] In this example, the centering block 8 includes a block-shaped body, a stop post 9 located on the upper surface of the block-shaped body, and a convex portion 18 located on the lower surface of the block-shaped body. The width of the block-shaped body of the centering block 8 is suitable for fitting into the radial groove 17 of the centering base plate 2. The ratio between the length of the centering block 8 and the length of the radial groove 17 enables the centering block 8 to have sufficient sliding space in the radial groove 17 and can move the required distance therein.

[0078] The convex portion 18 is complementary in shape to the involute spiral guide rail 7 of the centering turntable 6. Since in Figure 1 the example, the involute spiral guide rail 7 is in the form of a spiral groove, the convex portion 18 is formed on the lower surface of the block-shaped body to cooperate with it. The convex portion 18 below the centering stop 8 can be embedded in the spiral groove, and as the spiral groove rotates, it drives the centering stop 8 and drives the stop post 9; the spiral groove can be through or non-through, as long as the convex portion 18 can be embedded into the spiral groove. In an alternative embodiment, if the involute spiral guide rail 7 is in other forms, such as a convex track or a rod shape, the convex portion 18 can be deformed into a groove or a through hole to cooperate with it.

[0079] The number of the convex portions 18 and the stop posts 9 can be set as required. In addition, as described above, the position of the column 9 on the centering stop 8 can be designed to be adjustable, so as to compensate for the distance difference between the spiral guide rail and the center position at each phase.

[0080] The figure also shows a through hole on the block-shaped body of the centering stop for the linear guide rail 5 to pass through. The linear guide rail 5 can directly pass through this through hole; or it can pass through this through hole through a linear bearing, which will be described in detail below.

[0081] Figure 5 is Figure 1 a schematic installation diagram of the centering stop of the wafer centering and positioning device on the guide shaft. This figure shows the centering base plate 2, the wafer 30, the centering stop 8, the column 9, the linear guide rail 5, and the linear bearing 20.

[0082] As can be seen from the figure, the centering stop 8 is installed on the guide shaft, that is, the linear guide rail 5, through the linear bearing 20. The column 9 abuts against the edge of the wafer 30. When the centering turntable 6 rotates and the spiral guide rail pushes the centering stop 8, the centering stop 8 can move along the radial groove 7 and push against the wafer. Only one phase of the centering stop 8 is shown in the figure; it can be understood that when the centering turntable 6 rotates, the centering stops 8 at each phase will simultaneously approach the wafer edge and push the wafer. In the present application, the phase refers to the position along the circumference.

[0083] Figure 6 Schematically shows Figure 5 the linear bearing between the centering stop and the guide shaft in

[0084] Combined with Figure 5 it can be clearly seen that the centering stop 8 is slidably connected to the guide shaft, that is, the linear guide rail 5, via the linear bearing 20. The linear bearing 20 includes an end portion having two connection holes as shown and a cylindrical body portion, and the body portion has a through hole for the linear guide rail 5 to pass through.

[0085] Specifically, as shown in the figure, the end of the linear bearing 20 has two through holes for connection, and a through hole for the linear guide 5 to pass through the bearing is shown in the middle.

[0086] Combined Figure 5 It can be seen that the linear bearing 20 can be bolt - connected to the end of the centering block 8 through the two through holes at the end. Without using the linear bearing 20, the direct friction between the centering block and the guide shaft (i.e., the linear guide) will cause the hole in the centering block that mates with the guide shaft to gradually become larger, affecting the centering accuracy, and there is likely to be abnormal noise during direct friction. By using the linear bearing 20, since there are balls inside the bearing and the linear bearing is derived for linear motion cooperation with the shaft, the sliding is smooth, the structure is stable, and the repeat accuracy is high.

[0087] Figure 7 Schematically shown Figure 5 The installation diagram of the guide shaft on the centering base plate.

[0088] The figure shows the centering base plate 2, the radial groove 17, the centering block 8, the linear bearing 20, and the set screw 19 for fixing the guide shaft. As shown in the figure, both ends of the guide shaft are fixed to the centering base plate 2 through the set screws 19. Radial holes are formed from the outer peripheral edge of the centering base plate 2, and the two sections of radial holes are respectively located at both ends of the radial groove 17, and the guide shaft can extend from the outer peripheral edge of the centering base plate 2. This setting facilitates the disassembly, installation, and replacement of the guide shaft. The set screw 19 is fixed from the back of the centering base plate 2, which can avoid leaving unnecessary structures on the top surface of the centering base plate, damaging the flatness, and accidentally affecting production.

[0089] The wafer center positioning device of the present invention can be used in wafer thinning equipment. In wafer thinning equipment, the transfer mechanism takes out the wafer from the wafer storage cassette, then transfers and places it on the wafer center positioning device of the present invention. After centering by the wafer center positioning device of the present invention, the manipulator then takes the wafer away from the wafer center positioning device of the present invention. The wafer center positioning device can be used at any required position in wafer thinning equipment.

[0090] The wafer center positioning device of the present invention has a centering base plate and a centering turntable. A radial groove is opened in the centering base plate and a linear guide is installed. A spiral guide is provided on the centering turntable. When the centering turntable rotates relative to the centering base plate, the linear guide and the spiral guide act together to push the retaining post of the centering block towards the center position to push the wafer, realizing the centering and positioning of the wafer. This embodiment of the present invention can achieve the center positioning of wafers of different sizes, and is simple as a whole, operates stably, and has a high repeat positioning accuracy.

[0091] One aspect of the present invention further provides a wafer centering method using a wafer centering positioning device as described in any of the aforementioned embodiments, wherein the method comprises the following steps: a blocking column makes room for receiving wafers according to the size of the wafer; receiving the wafer on a vacuum suction cup on a centering base; controlling the movement of the blocking block to allow the blocking column to push the wafer to be centered; and stopping the centering when the pushing action of the blocking column reaches the wafer size. In the step of the blocking column making room for receiving wafers according to the size of the wafer, it can be achieved by sensor induction control, and the sensor can be set on the centering base. In the step of receiving the wafer on the vacuum suction cup on the centering base, the wafer can be placed on the vacuum suction cup by a robot. In the step of controlling the movement of the blocking block to allow the blocking column to push the wafer to be centered, it can be achieved by as Figure 1 The driving motor shown in the figure drives the stopper to realize. In the step of stopping the centering when the pushing action of the stopper column reaches the wafer size, the blocking pushing distance is determined by the predetermined size, which can advantageously prevent the wafer from breaking.

[0092] Figure 8 A three-dimensional view of an embodiment of a wafer thinning device of the present invention is schematically shown, and a wafer transfer device is also shown in the middle.

[0093] The wafer transfer device 34 shown in the figure includes a moving mechanism 200 and a wafer centering and positioning device 1 according to the present invention. Figure 8 As shown. The wafer centering and positioning device 1 is connected to the moving mechanism 200, and the moving mechanism 200 drives the wafer centering and positioning device 1 to move so as to realize the transmission of the wafer. As an embodiment of the present invention, the moving mechanism 200 is a linear module, and the moving mechanism 200 accelerates or decelerates to move. The wafer centering and positioning device 1 arranged on the moving mechanism 200 can effectively maintain the centering position of the wafer during the transmission process, avoid the position of the wafer being offset during the transmission process, prevent the wafer from sliding off the wafer centering and positioning device 1, and ensure the stability of the wafer transmission.

[0094] As another aspect of the present invention, the present invention also provides a wafer thinning device, such as Figure 8 As shown, the wafer thinning equipment includes a front-end module 38, which is located at the front end of the wafer thinning equipment and is used to realize the entry and exit of the wafer; a grinding module 31, which is located at the end of the wafer thinning equipment and is used for grinding the wafer; a polishing module 41, which is located between the front-end module 38 and the grinding module 31 and is used for chemical mechanical polishing of the wafer; it also includes the wafer transfer device 34 mentioned above, which is parallel to the polishing module 41 and is located between the front-end module 38 and the grinding module 31.

[0095] exist Figure 8In the illustrated embodiment, the wafer thinning device further includes a buffer module 37, which is disposed adjacent to the front-end module 38 and located between the front-end module 38 and the wafer transfer device 34. In some embodiments, the wafer centering and positioning device 1 of the present invention may be configured on the buffer module 37.

[0096] The wafer is transferred from the front-end module 38 to the buffer module 37 by the first robot 39; the wafer on the buffer module 37 is transferred from the buffer module 37 to the wafer centering and positioning device 1 of the wafer transfer device 34 by the second robot 36; the position of the wafer is adjusted in the wafer centering and positioning device 1 so that the wafer is concentric with the base of the wafer centering and positioning device 1; the moving mechanism of the wafer transfer device 34 drives the wafer to move from the first position 35 close to the buffer module 37 to the second position 33 close to the grinding module 31, and the second position 33 is the wafer centering and positioning device 1 represented by the dashed line; the third robot 32 transfers the wafer located at the second position 33 to the grinding table 42 of the grinding module 31.

[0097] Since the wafer centering and positioning device 1 of the wafer transfer device 34 effectively maintains the position of the wafer, the concentricity between the wafer transferred by the third robot 32 and the grinding table 42 is relatively high, further ensuring the concentricity between the wafer and the grinding table 42. The wafer completely covers the negative pressure adsorption area on the grinding table 42, avoiding the occurrence of the "air leakage" phenomenon and effectively ensuring the reliability of wafer adsorption; the concentric setting of the wafer and the grinding table 42 is also beneficial to ensuring the consistency of the grinding contact arc length of the wafer, improving the stability of the grinding force and effectively controlling the quality of the grinding surface.

[0098] The drawings in this specification are schematic diagrams, which assist in explaining the concept of the present invention and schematically show the shapes of various parts and their mutual relationships. It should be understood that in order to clearly show the structures of the components in the embodiments of the present invention, the drawings are not drawn in the same proportion, and the same reference numerals are used to represent the same parts in the drawings.

[0099] The technical scope of the present invention is not limited to the content in the above specification. Those skilled in the art can make various deformations and modifications to the above embodiments without departing from the technical idea of the present invention, and these deformations and modifications should all fall within the scope of the present invention.

Claims

1. A wafer centering and positioning device, characterized in that: include: A frame, comprising a base and at least three columns evenly distributed on the base; A motor bracket is installed on the base, the columns are distributed on the periphery of the motor bracket, and leveling bolts are arranged at the periphery of the bottom of the motor bracket; a drive motor, the top of which is fixed to the top of the motor bracket and the bottom of the drive motor is suspended in the air, the leveling bolt being configured to adjust the level of the motor bracket relative to the base to adjust the level of the drive motor; A centering base, which is fixed to the base through the column, the centering base provides a wafer centering center, and the centering base is provided with N linear guide rails distributed circumferentially and extending radially with the wafer centering center as the center. N≥3； A centering turntable, which is arranged below the centering base and driven by the driving motor to rotate relative to the centering base, the rotation center of the centering turntable is aligned with the wafer centering center, and the centering turntable is provided with an involute spiral guide rail; as well as N centering blocks, each of which is provided with a stop column extending out of the top surface of the centering base plate, the N centering blocks are slidably mounted on the involute spiral guide rails and are slidably mounted on the N linear guide rails respectively, when the centering turntable rotates around the rotation center, the centering blocks can slide along the involute spiral guide rails and the linear guide rails at the same time, and at each circumferential angle of the centering turntable, the center distance from each stop column to the rotation center is always equal, so as to push the wafer to the centering position.

2. The wafer centering and positioning device according to claim 1, characterized in that: The driving motor is configured to drive the centering turntable in reverse to make the stopper column of the centering stopper retreat on the centering base to make room for placing the wafer, and after placing the wafer to be centered in place, drive the centering turntable in forward direction to tighten the centering stopper to perform the centering action.

3. The wafer centering and positioning device according to claim 1, characterized in that: The N linear guide rails are evenly distributed along the circumferential direction with the wafer centering center as the center of the circle.

4. The wafer centering and positioning device according to claim 1, characterized in that: The centering base is provided with a vacuum suction cup at the center of the wafer for adsorbing and fixing the wafer after centering, and the top plane of the vacuum suction cup protrudes from the top surface of the centering base.

5. The wafer centering and positioning device according to claim 1, characterized in that: The involute spiral guide is a spiral groove, the linear guide is a guide shaft, an axially penetrating radial groove is provided in the centering base plate, the guide shaft is fixed in the radial groove, the bottom of the centering block has a protrusion suitable for extending into the spiral groove to slide along the spiral groove, the centering block is sleeved on the guide shaft and is located in the radial groove.

6. The wafer centering and positioning device according to claim 5, characterized in that: The two ends of the guide shaft are respectively fixed to the centering base plate through top screws.

7. The wafer centering and positioning device according to claim 5, characterized in that: The centering block is mounted on the guide shaft via a linear bearing.

8. The wafer centering and positioning device according to any one of claims 1 to 7, characterized in that: The involute spiral guide rail is an equidistant spiral guide rail, and at each rotation angle of the centering turntable, the center distance increments of the equidistant spiral guide rail are equal.

9. The wafer centering and positioning device according to claim 8, characterized in that: The position of the blocking column on the centering block is arranged so that, when the centering block is mounted on the wafer centering positioning device, the distance between the blocking column on each centering block and the wafer centering center is the same.

10. The wafer centering and positioning device according to claim 9, characterized in that: The blocking column is arranged to be radially movable and adjustable, and a blocking column position radial adjustment mechanism is arranged on the centering block. The blocking column position radial adjustment mechanism is provided with adjustment marks according to the spacing angles of each centering block, so as to adjust and compensate for the radial displacement difference of the blocking column.

11. The wafer centering and positioning device according to any one of claims 1 to 7, characterized in that: The centering turntable is provided with N involute spiral guide rails, which have the same size and shape and are evenly arranged on the circumference. Each centering block is respectively installed on a different involute spiral guide rail, and the centering blocks are evenly distributed along the circumference.

12. The wafer centering and positioning device according to any one of claims 1 to 7, characterized in that: The centering base is located on the top of the wafer centering positioning device.

13. The wafer centering and positioning device according to claim 1 or 2, characterized in that: A sensor is provided on the centering base, and the sensor is used to identify the size of the wafer. In addition, the wafer centering positioning device is configured to control the drive motor to drive the centering block to move away from the wafer centering center to make room for placing the wafer after the sensor identifies the size of the wafer. After the wafer to be centered is placed in place, the centering block is driven to move toward the wafer centering center to perform the centering action.

14. A wafer transfer device, characterized in that: The wafer transfer device comprises a wafer centering and positioning device as described in any one of claims 1 to 13 and a moving mechanism, wherein the wafer centering and positioning device is used to adjust the position of the wafer, and the wafer centering and positioning device is connected to the moving mechanism so that the moving mechanism drives the wafer centering and positioning device to move.

15. A wafer thinning device, characterized in that: The wafer thinning equipment comprises: The front-end module is located at the front end of the wafer thinning equipment and is used to enable the wafer to enter and exit; A grinding module, which is located at the end of the wafer thinning equipment and is used for grinding the wafer; A polishing module, located between the front-end module and the grinding module, for chemical mechanical polishing of the wafer; and The wafer transfer device as claimed in claim 14 is parallel to the polishing module and located between the front-end module and the grinding module.

16. A wafer centering method using the wafer centering and positioning device according to any one of claims 1 to 15, characterized in that: The method comprises the following steps: The blocking pillars make room for receiving wafers according to the size of the wafers; Receiving the wafer on a vacuum chuck on a centering base; Controlling the movement of the stopper so that the stopper column pushes the wafer to center; as well as When the push action of the stopper reaches the wafer size, the centering stops.

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