Edge searching mechanism and centering edge searching mechanism

Abstract

The utility model provides an edge searching mechanism used for searching a positioning edge of a wafer, and belongs to the technical field of wafer processing, the edge searching mechanism comprises a positioning base used for placing the wafer, the center of the positioning base and the circle center of the wafer are located on the same axis, the positioning base is provided with at least two air blowing holes suitable for blowing air upwards, and the air blowing holes are used for blowing air upwards. The at least two air blowing holes are suitable for being communicated with an air source, the linear outline formed by the connecting line of the centers of the at least two air blowing holes is consistent with the linear outline of the positioning edge, and the at least two air blowing holes are located in the positions, corresponding to the position where the positioning edge of the expected wafer orientation is located, of the positioning base; and the detection mechanism is used for detecting whether the blowing holes are shielded by the wafer, and when the fact that the at least two blowing holes are not shielded by the wafer is detected, the linear contours formed by the positioning edge of the wafer and the at least two blowing holes are equidistant lines. The defect that in the prior art, the wafer centering edge searching cost is high is overcome.

Description

Technical Field

[0001] The present application relates to the field of wafer processing technology, and in particular to a centering mechanism. Background Art

[0002] A wafer is the substrate used to manufacture semiconductor transistors or integrated circuits. Due to precision requirements for wafer processing, some wafers are cut with a notch. This notch is used to precisely locate the wafer, a process known as wafer edge finding.

[0003] During the wafer manufacturing process, wafers need to be frequently transferred between different carriers and wafer boxes. Since the position of the wafers may be offset by millimeters when the robot takes and places the wafers from the slots of the wafer box, problems such as inaccurate wafer positioning, eccentricity, and unstable direction of the positioning edge may occur when the wafers are moved to the carrier.

[0004] Existing centering devices usually place the wafer on a movable vacuum chuck and rotate the wafer while using optical instruments to find the edge of the wafer. However, existing optical instruments occupy the space above the wafer during the wafer edge finding process, and optical instruments are expensive, resulting in high edge finding costs. Summary of the Invention

[0005] The purpose of this application is to provide an edge-finding mechanism and a centering edge-finding mechanism, aiming to solve the defects of the wafer edge-finding process in the related art in that the space above the wafer position is occupied and the edge-finding cost is high.

[0006] Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.

[0007] According to the first aspect of the present application, there is provided an edge-finding mechanism for finding the positioning edge of a wafer, comprising: a positioning base for placing the wafer, the center of the positioning base and the center of the wafer being located on the same axis, the positioning base being provided with at least two blowing holes suitable for blowing air upward, the at least two blowing holes being suitable for connecting to an air source, the linear contour formed by the line connecting the centers of the at least two blowing holes being consistent with the linear contour of the positioning edge, the at least two blowing holes being located at positions on the positioning base corresponding to the positions of the positioning edges of the expected wafer orientation; a detection mechanism being arranged corresponding to the at least two blowing holes and being used for detecting the air pressure values in the blowing holes, and when it is detected that the air pressure values of the at least two blowing holes are both reduced and the reduced air pressure values are consistent, the positioning edge of the wafer and the linear contour formed by the at least two blowing holes are equidistant lines from each other.

[0008] In an exemplary embodiment of the present application, the positioning edge is a short edge formed on the edge of the wafer; and the linear profile formed by the line connecting the centers of the at least two blowing holes is a straight line.

[0009] In an exemplary embodiment of the present application, the positioning base is a hollow structure; the edge-finding mechanism also includes: a vacuum suction cup, rotatably arranged at the hollow structure of the positioning base, the vacuum suction cup is used to abut against the lower surface of the wafer, and the center of the vacuum suction cup and the center of the wafer are located on the same axis; a central axis, located below the vacuum suction cup and fixedly connected to the vacuum suction cup at one end, the axis of the central axis is coaxial with the center of the vacuum suction cup, an air channel is formed inside the central axis, and the air channel is connected to the vacuum suction cup; a rotation drive mechanism is used to drive the central axis to rotate; the rotation drive mechanism is configured to drive the central axis to drive the vacuum suction cup and the wafer to rotate when the detection mechanism detects that the air pressure values of the at least two blowing holes have not decreased or the reduced air pressure values are inconsistent, and stop driving when the detection mechanism detects that the air pressure values of the at least two blowing holes have decreased to the same value.

[0010] In an exemplary embodiment of the present application, the detection mechanism includes a pressure switch for detecting the air pressure in each of the blowing holes. When the blowing holes are blocked by the wafer, the pressure switch will generate pressure and the pressure value will reach a maximum state. The rotation drive mechanism starts to drive the central axis to rotate in response to the pressure value of the maximum state; when the contours of all the blowing holes are flush with the positioning edge of the wafer, the pressure values of all the pressure switches are reduced to the same value, and the rotation drive mechanism stops driving the central axis to rotate.

[0011] In an exemplary embodiment of the present application, the detection mechanism also includes a quick-plug connector and an air duct, the pressure switch is installed on the air duct, one end of the air duct is connected to the air hole through the quick-plug connector, and the other end of the air duct is connected to the air source.

[0012] In an exemplary embodiment of the present application, the rotary drive mechanism includes a rotary power output device for providing rotary power and a transmission device for transmitting the rotary power generated by the rotary power output device to the central shaft.

[0013] In an exemplary embodiment of the present application, the rotational power output device is a drive motor, and the transmission device includes a driving wheel, a driven wheel and a synchronous belt. The driving wheel is located on one side of the central axis, and the rotation axis is parallel to the length direction of the central axis. The output shaft of the driving motor is fixedly connected to the center of the driving wheel; the driven wheel and the driving wheel are located at the same horizontal height, the central axis passes through the center of the driven wheel and is fixedly connected to the driven wheel, and the synchronous belt is wrapped around the driving wheel and the driven wheel.

[0014] According to a second aspect of the present application, a centering and edge-finding mechanism is provided, comprising the edge-finding mechanism; and a centering mechanism, wherein the centering mechanism is configured to place the center of the wafer and the center of the positioning base on the same axis.

[0015] In an exemplary embodiment of the present application, the centering mechanism includes: at least three groups of centering devices, which are arranged around the positioning base in an interval-surrounding manner, and each group of the centering devices is at an equal distance from the center of the positioning base; a synchronous driving device, which is configured to drive the at least three groups of centering devices to move the same distance toward or away from the center of the positioning base at the same time. When driving the at least three groups of centering devices to move the same distance toward the center of the positioning base at the same time, the centering device pushes the wafer so that the center of the wafer and the center of the positioning base are on the same axis.

[0016] In an exemplary embodiment of the present application, radial channels corresponding to the at least three groups of centering devices are opened on the side wall of the positioning base, and the radial channels are directed toward the center of the positioning base; the centering device includes: a limit member having a limit surface directed toward the center of the positioning base for pushing the wafer; a guide member movably installed in the radial channel, an end of the guide member away from the center of the positioning base extends out of the positioning base, and the limit member is installed on this end; the end of the guide member close to the positioning base is configured to be driven by the synchronous drive device so that the guide member can slide back and forth in the radial channel.

[0017] In an exemplary embodiment of the present application, the radial channel is a radial hole; the guide member is a guide rod inserted into the radial hole; the centering device also includes a spring and a spring baffle, the spring is sleeved on the guide rod, the spring baffle is fixed at the opening of the radial hole on the side away from the center of the positioning base, the end of the spring close to the center of the positioning base is connected to the guide rod, and the end of the spring away from the positioning base abuts against the spring baffle; the end of the guide rod away from the center of the positioning base passes through the spring baffle and extends out of the positioning base.

[0018] In an exemplary embodiment of the present application, the synchronous drive device includes a cam and a rotation drive device, the rotation drive device is used to drive the cam to rotate; the center of the cam is coaxial with the center of the positioning base, and the edge of the cam is provided with at least three protrusions corresponding to at least three guide rods, and at least three grooves are formed between the at least three protrusions; when the cam rotates, the protrusion is used to push the guide rod to overcome the elastic force of the spring and move in a direction away from the center of the positioning base, and the groove is used for the guide rod to move toward the center of the positioning base under the action of the release of the elastic force of the spring.

[0019] In an exemplary embodiment of the present application, the centering device further includes a follower mounted on one end of the guide rod close to the center of the positioning base, the follower abuts against the edge of the cam, and the cam drives the guide rod to move through the follower.

[0020] In an exemplary embodiment of the present application, the follower includes: a connecting rod, one end of which is fixedly connected to the guide rod, and the extension direction of the connecting rod is parallel to the axis of the cam; a guide wheel, which is installed at the other end of the connecting rod, and the edge of the guide wheel abuts against the edge of the cam.

[0021] In an exemplary embodiment of the present application, a rotation drive device is further included for driving the cam to rotate, and the rotation drive device further includes: a gear, which coincides with the axis of the cam and is fixedly connected to the cam; a rack, which meshes with the gear; and a driving member, which is used to drive the rack to move linearly in a horizontal direction.

[0022] In an exemplary embodiment of the present application, the central shaft passes through the centers of the gear and the cam in sequence in a vertical direction, and the central shaft is rotatably connected to the gear and the cam; a boss is fixedly provided on the lower surface of the cam, the center of the gear is a hollow structure, the boss is located inside the gear and is fixedly connected to the gear, a bearing seat is provided between the boss and the central shaft, and bearings are installed between the outer side and the inner side of the bearing seat and the boss and the central shaft respectively.

[0023] The exemplary embodiments of the present application may have some or all of the following beneficial effects:

[0024] 1. In an edge-finding mechanism provided in an exemplary embodiment of the present application, at least two air blowing holes suitable for blowing air upward are provided on a positioning base, and the linear profile formed by the center line connecting the at least two air blowing holes is consistent with the linear profile of the wafer positioning edge, and the at least two positioning holes are provided at positions on the positioning base corresponding to the position of the positioning edge of the expected wafer orientation. When the detection mechanism detects that the air pressure values of the at least two air blowing holes are reduced and the reduced air pressure values are consistent, the positioning edge of the wafer is aligned with the linear profile formed by the at least two air blowing holes. Since the linear profile formed by the at least two air blowing holes corresponds to the position of the positioning edge of the expected wafer orientation, when the positioning edge of the wafer is aligned with the linear profile formed by the at least two air blowing holes, it means that the positioning edge of the wafer has moved to the position of the positioning edge of the expected wafer orientation, that is, the edge-finding is completed. Compared with the process of wafer edge-finding by optical instruments in the related art, the edge-finding mechanism provided in the exemplary embodiment of the present application does not occupy space above the wafer position in actual use and has a simple structure and low price.

[0025] 2. In an edge-finding mechanism provided in an exemplary embodiment of the present application, a pressure switch can monitor the air pressure in the blow hole. If the air pressure value is found to be at a maximum state (the blow hole is completely blocked by the wafer) or an uneven state (part of the blow hole is blocked by the wafer or the areas of the blow hole blocked by the wafer are different), it means that the contour of the positioning edge does not match the contour of the line connecting the centers of the blow holes, and the wafer position needs to be adjusted. When the contour of the wafer positioning edge is adjusted to match the contour of the line connecting the centers of the blow holes, gas can be discharged from the blow hole, and the air pressure value is reduced to the same value. Therefore, the above structure makes it convenient for personnel to determine the position of the positioning edge.

[0026] 3. In an edge-finding mechanism provided in an exemplary embodiment of the present application, when the pressure switch detects pressure, the suction cup first vents air through the central shaft, allowing the suction cup to adhere to the wafer and secure it. The drive device then rotates the central shaft, suction cup, and wafer until the contour of the wafer's positioning edge aligns with the contour of the line connecting the centers of the air holes. This structure facilitates wafer adjustment for operators.

[0027] 4. In a centering and edge-finding mechanism provided in an exemplary embodiment of the present application, a synchronous drive device first drives a centering device away from the center of a positioning base to facilitate placement of a wafer on the wafer base. The synchronous drive device then drives multiple centering devices to simultaneously move the same distance toward the center of the positioning base. This allows the crystal to be subjected to equal forces in multiple directions, thereby moving the wafer until its center and the center of the positioning base are coaxial, thereby centering the wafer. This mechanism has a relatively simple structure and low manufacturing cost. It does not require space above the wafer, thereby reducing the cost of wafer centering.

[0028] 5. In a centering and edge-finding mechanism provided in an exemplary embodiment of the present application, a cam is rotated. When the cam's raised portion abuts against a guide wheel in a follower, a connecting rod in the follower drives a stopper away from the center of a positioning base, facilitating placement of a wafer on the positioning base.

[0029] 6. In a centering and edge-finding mechanism provided in an example embodiment of the present application, the cam is rotated again so that the groove portion of the cam abuts against the guide wheel in the follower, and the spring releases the elastic force, driving the limit member to move toward the center direction of the positioning base to center the wafer. Through this structure, multiple limit members can be moved simultaneously to achieve the effect of centering the wafer.

[0030] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0032] Figure 1 A schematic structural diagram of a centering and edge-finding mechanism provided in an exemplary embodiment of the present application is shown;

[0033] Figure 2 Shown Figure 1 A top view of

[0034] Figure 3 Shown Figure 2 Enlarged view of part A;

[0035] Figure 4 Shown Figure 1 Cross-sectional view along the AA direction;

[0036] Figure 5 Shown Figure 1 Cross-sectional view along direction BB.

[0037] Description of reference numerals:

[0038] 1. Positioning base; 11. Blowing hole; 2. Centering device; 21. Limiting member; 22. Guide rod; 221. Step portion; 23. Spring; 24. Spring baffle; 25. Follower; 251. Connecting rod; 252. Guide wheel; 3. Synchronous drive device; 31. Cam; 311. Raised portion; 312. Grooved portion; 313. Boss; 32. Rotary drive device; 321. Gear; 322. Rack; 323. Driving member; 4. Base plate; 41. Bracket; 42. Guide rail base; 421. Linear guide; 5. Vacuum suction cup; 51. Central shaft; 6. Rotary power output device; 7. Transmission device; 71. Driving wheel; 72. Driven wheel; 73. Synchronous belt; 8. Bearing seat; 81. Needle roller bearing; 82. Deep groove ball bearing; 9. Pressure switch. DETAILED DESCRIPTION

[0039] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this application will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the figures represent like or similar structures, and thus their detailed descriptions will be omitted. Furthermore, the figures are merely schematic illustrations of the present application and are not necessarily drawn to scale.

[0040] While relative terms such as "upper" and "lower" are used in this specification to describe the relationship of one illustrated component to another, these terms are used for convenience only, such as in accordance with the orientation of the illustrations in the accompanying drawings. It should be understood that if the illustrated device were flipped upside down, the component described as "upper" would become the component "lower." When a structure is referred to as "on" another structure, this may mean that the structure is integrally formed with the other structure, that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through the other structure.

[0041] The terms "a", "an", "the" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express open-ended inclusion and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc.; the terms "first" and "second" are used only as labels and do not limit the quantity of their objects.

[0042] In related technologies, the cross-section of a wafer is typically circular, and during the cutting process, a positioning edge is formed, which is used for subsequent processing alignment. The edge-finding mechanism is designed to automatically detect and identify this positioning edge, ensuring that various micromachining operations on the wafer (such as lithography, etching, or deposition) are precisely aligned. Through precise positioning, the manufacturing quality of each chip and the utilization rate of the entire wafer can be improved, thereby optimizing the production efficiency and performance of semiconductor devices.

[0043] Example 1

[0044] like Figure 1 and Figure 2 As shown, this embodiment provides an edge-finding mechanism for finding the positioning edge of a wafer, comprising:

[0045] A positioning base 1 is used to place the wafer, the center of the positioning base 1 and the center of the wafer are located on the same axis, the positioning base 1 is provided with at least two blowing holes 11 suitable for blowing air upward, the at least two blowing holes 11 are suitable for connecting to an air source, the linear profile formed by the center line of the at least two blowing holes 11 is consistent with the linear profile of the positioning edge, and the at least two blowing holes 11 are located at positions on the positioning base 1 corresponding to the position of the positioning edge of the expected wafer orientation;

[0046] The detection mechanism is arranged corresponding to the at least two air holes 11, and is used to detect the air pressure value in the air hole 11. When it is detected that the air pressure values of the at least two air holes 11 are reduced and the reduced air pressure values are consistent, the positioning edge of the wafer and the linear contours formed by the at least two air holes 11 are equidistant lines from each other.

[0047] In the embodiment of the present application, the cross-section of the positioning base 1 is circular, the center of the positioning base 1 is a hollow structure, the vacuum suction cup 5 is located on the inner side of the positioning base 1 and is rotatably connected to the positioning base 1, and the upper surface of the vacuum suction cup is highly consistent with the upper surface of the positioning base 1, so that the upper surfaces of the two are flush, so that the wafer can be placed horizontally; the blowing hole 11 is opened on the upper surface of the positioning base 1 and passes through to the lower surface of the positioning base 1. In the embodiment of the present application, the cross-sectional shape of the positioning base 1 can also be circular, triangular, or irregular.

[0048] like Figure 2 and Figure 3As shown, the shape of the positioning edge is not restrictive and can be either linear or V-shaped. In this embodiment, a linear shape is preferred, and two blowing holes 11 are provided. The straight line connecting the centers of the two blowing holes 11 and the outline of the positioning edge are equidistant from each other. In other words, the linear outline formed by the two blowing holes 11 can be parallel to the positioning edge or completely overlap. It is understood that when the linear outline formed by the positioning edge and the blowing holes 11 reaches the equidistant line, the two blowing holes 11 achieve the same degree of gas conduction. In other words, the area blocked by the wafer from the two blowing holes is the same.

[0049] Furthermore, when the positioning edge reaches the point where it is equidistant from the straight line contour connected to the center of the blowing holes 11, the shortest distance allowed from the center of the wafer to the positioning edge is that the positioning edge is just tangent to the tops of the two blowing holes 11, that is, the two blowing holes 11 are just completely exposed on the outside of the positioning edge of the wafer; the maximum distance allowed from the center of the wafer to the positioning edge is that the positioning edge is just tangent to the bottoms of the two blowing holes 11, that is, the two blowing holes 11 are just completely blocked on the inside by the positioning edge of the wafer.

[0050] Therefore, it can be deduced that the allowable range of the wafer positioning edge is:

[0051] -r≤lx≤r

[0052] Wherein, r is the radius of the blowing hole 11 , l is the distance from the center of the wafer to the positioning edge, and x is the distance from the center of the positioning base 1 to the line connecting the centers of the two blowing holes 11 .

[0053] like Figure 4 As shown, in order to achieve the inflation and deflation of the vacuum suction cup 5, a central shaft 51 is provided vertically below the suction cup. An air channel is formed inside the central shaft 51 along its length, and the air channel is connected to the suction cup. When the wafer needs to be adsorbed, the central shaft 51 allows air to be drawn out of the vacuum suction cup 5 and discharged through the air channel, creating a vacuum, thereby firmly fixing the wafer to the surface of the vacuum suction cup 5. Conversely, when the wafer needs to be released, the central shaft 51 introduces air through the air channel, breaking the vacuum, so that the vacuum suction cup 5 can release the wafer without damage.

[0054] When the positioning edge position needs to be determined, an air source is used to ventilate the air holes 11 of the positioning base 1. If the detection mechanism detects that the air pressure values in the two air holes 11 are different, this indicates that the positioning edge of the wafer is not yet aligned with the straight line where the center of the air holes 11 is located, because the area blocked by the wafer by the two air holes 11 is different. At this time, the vacuum suction cup 5 exhausts air through the lower central axis 51, forming a vacuum adsorption between it and the wafer, ensuring that the two are stable relative to each other. Subsequently, the angle of the vacuum suction cup 5 is gradually adjusted, and the wafer rotates accordingly. Until the detection mechanism detects that the air pressure values in all air holes 11 are the same, this indicates that the connection between the positioning edge of the wafer and the center of the air holes 11 has reached an equidistant line, thereby achieving the purpose of precise positioning. Of course, the number of air holes 11 can also be three, four, or more, but when the positioning edge is a straight line, regardless of the number of air holes 11, all air holes 11 must be located on the same straight line.

[0055] In the embodiment of the present application, to facilitate rotation of the vacuum chuck by the operator, the edge-finding mechanism also includes a rotation drive mechanism for the vacuum chuck 5. The structure of the rotation drive mechanism is not restrictive and can be adapted to various mechanical structures that can achieve rotation of the vacuum chuck, such as an electric motor, a hydraulic or pneumatic system, a servo mechanism, etc. The key point is that, regardless of the structure adopted, the device must be able to reliably control the rotation of the vacuum chuck to accurately adjust the position of the wafer.

[0056] like Figure 1 As shown, as a preferred embodiment of the present application, the rotary drive mechanism includes: a rotary power output device 6 and a transmission device 7. The rotary power output device 6 is a drive motor; the transmission device 7 includes: a driving wheel 71, a driven wheel 72 and a synchronous belt 73; the driving wheel 71 is rotatably arranged on one side of the central shaft 51, and the rotation axis of the driving wheel 71 is parallel to the length direction of the central shaft 51. The driven wheel 72 is located at the same horizontal height as the driving wheel 71. The central shaft 51 passes through the center of the driven wheel 72 and is fixedly connected to the driven wheel 72. The fixing method of the central shaft 51 and the driven wheel 72 is not limited. It can be fixed by welding, or it can be connected and fixed by means of clamping, threading, etc. The synchronous belt 73 is wrapped around the driving wheel 71 and the driven wheel 72. The driving motor is arranged directly below the driving wheel 71 as the power source of the driving wheel 71, and the output shaft of the driving motor is fixedly connected to the center of the driving wheel 71. The driving motor drives the driving wheel 71 to rotate, and the driving wheel 71 drives the driven wheel 72 to rotate through the synchronous belt 73. The driven wheel 72 drives the central shaft 51 to rotate, and the central shaft 51 drives the suction cup to rotate, thereby achieving the effect of rotating the wafer.

[0057] Furthermore, in the embodiments of the present application, there is no restriction on the gas source, and a variety of equipment can be used, such as an air pump, a blower or an air bleeder, as long as it can deliver gas to the air hole.

[0058] like Figure 1 and Figure 2 As shown, in an embodiment of the present application, the detection mechanism includes a pressure switch 9, a quick connector and an air duct. One end of the air duct is connected to the air source, and the other end of the air duct is connected to the port of the air hole 11 on the lower surface of the positioning base 1 through a quick connector. The pressure switch 9 is installed on the wall of the air duct and can monitor the air pressure value in the air duct. When the wafer blocks the air hole 11, the pressure switch 9 will detect the air pressure value in the air hole 11. When the pressure switch 9 shows that the air pressure values in the two air ducts are different, the drive motor starts until the air pressure values in the two air ducts reach the same value, indicating that all the air holes 11 are unblocked. At this time, the positioning edge of the wafer has been aligned, the edge-finding process is completed, and the drive motor stops working. This automated process ensures the precise positioning of the positioning edge of the wafer.

[0059] Example 2

[0060] This embodiment provides a centering and edge-finding mechanism, including: a centering mechanism and an edge-finding mechanism. The edge-finding mechanism is the specific structure described in Example 1, and the centering mechanism includes:

[0061] like Figure 1 and Figure 2 As shown, at least three sets of centering devices 2 are arranged around the positioning base 1 in an interval-surrounding manner, and each set of centering devices 2 is equidistant from the center of the positioning base 1;

[0062] The synchronous driving device 3 is configured to drive at least three groups of centering devices 2 to move the same distance toward or away from the center of the positioning base 1 at the same time. When driving at least three groups of centering devices 2 to move the same distance toward the center of the positioning base 1 at the same time, the centering device 2 pushes the wafer so that the center of the wafer and the center of the positioning base 1 are on the same axis.

[0063] In the embodiment of the present application, the synchronous drive device 3 first drives the centering device 2 away from the center of the positioning base 1, then places the wafer on the positioning base 1, and then drives the centering device 2 toward the center of the positioning base 1 through the synchronous drive device 3. When the center of the wafer and the center of the positioning base 1 are on the same axis, the limiter 21 no longer applies force to the wafer. The adjacent centering devices 2 are spaced equally apart. This ensures that during the wafer positioning process, force is applied to the wafer only when needed, improving the stability and accuracy of wafer positioning and reducing damage to the wafer.

[0064] In the present application, the number of centering devices 2 can be set to three, four, five, six or even more groups. Increasing the number of centering devices 2 can improve the effect of wafer centering and make wafer centering more accurate. At the same time, each group of positioning devices is at an equal distance from the center of the positioning base 1, which ensures that the positioning of the wafer in all directions is uniform, thereby improving the accuracy and stability of wafer positioning. In the embodiment of the present application, the centering devices 2 are preferably set to six groups.

[0065] In the embodiment of the present application, each set of centering devices 2 includes a limiting member 21 , and the limiting member 21 has a limiting surface on a side facing the positioning base 1 for pushing the wafer to move.

[0066] Furthermore, in order to improve the stability of the limiting member 21 during movement, a plurality of radial channels are provided on the sidewall of the positioning base 1, which are oriented toward the center of the positioning base 1. The radial channels correspond one-to-one with the centering device 2. The radial channels are preferably holes, but are not particularly limited thereto and may also be grooves or guide rails provided at the bottom of the positioning base 1. The centering device 2 also includes a guide member, which is capable of moving within the radial channel. The end of the guide member, which is away from the center of the positioning base 1, extends out of the positioning base 1 and is fixedly mounted to the limiting member 21. The end of the guide member, which is closer to the positioning base 1, is configured to be driven by a synchronous drive device 3 so that the guide member can slide back and forth within the radial channel.

[0067] In one embodiment of the present application, the synchronization device includes a drive disk and an articulated rod. Multiple articulated rods are provided, each corresponding to a plurality of stoppers 21. The ends of the articulated rods are respectively hinged to the sidewalls of the drive disk and the stoppers 21. By rotating the drive disk clockwise and counterclockwise, the stoppers 21 can be moved toward or away from the center of the positioning base 1 under the guidance of the guide members and radial channels.

[0068] like Figure 4 As shown, in another implementation of the embodiment of the present application, the radial channel is a radial hole, and the guide member is a guide rod 22 passing through the radial hole.

[0069] The centering device 2 also includes a spring 23 and a spring retainer 24. The spring 23 is positioned within the radial hole and is mounted on the guide rod 22. The spring retainer 24 is fixed to the opening of the radial hole away from the center of the positioning base 1. The end of the spring 23 near the center of the positioning base 1 is connected to the guide rod 22, while the end of the spring 23 away from the center of the positioning base 1 abuts the spring retainer 24. The method of connection between the spring 23 and the guide rod 22 is not particularly limited and can be welded or glued. As a preferred embodiment of the present application, the end of the guide rod 22 located within the radial hole is provided with a stepped portion 221, and the end of the spring 23 near the center of the positioning base 1 abuts the stepped portion 221. The spring retainer 24 is fixedly connected to the side wall of the positioning base 1. The connection method is not restrictive and can be bolted, welded, glued, or otherwise secured. This design allows the spring 23 to be stably stored within the radial hole. When the spring 23 releases its elastic potential energy, it can drive the guide rod 22 and the stopper 21 to move toward the center of the positioning base 1.

[0070] Furthermore, one end of the guide rod 22 away from the stepped portion 221 passes through the spring baffle 24 and is connected to the base limiter 21 on the outside of the radial hole. The connection method between the guide rod 22 and the limiter 21 is not particularly limited, and can be welding, clamping, pasting, interference fit, etc. The connection method between the guide rod 22 and the limiter 21 is preferably such that the limiter 21 can be moved and fixed on the guide rod 22, such as a threaded connection. Through this connection method, the position of the limiter 21 on the guide rod 22 can be adjusted to ensure that after the wafer size changes, the limiter 21 can still meet the requirement of not applying force to the wafer when it abuts against the side wall of the wafer.

[0071] In the embodiment of the present application, the synchronous drive device 3 includes a cam 31, which is located below the positioning base 1. The rotation axis of the cam 31 is coaxial with the center of the positioning base 1. The cam 31 is rotatably connected to the positioning base 1. The axial sidewall of the cam 31 is provided with a plurality of protrusions 311, and grooves 312 are formed between adjacent protrusions 311. The number and position of the protrusions 311 and the grooves 312 match those of the centering device 2. Therefore, in the present application, six protrusions 311 are provided, and adjacent protrusions 311 are equally spaced. This design makes the rotation of the cam 31 more stable and uniform, and improves the accuracy and effect of centering.

[0072] Furthermore, in order to enable the rotation of the cam 31 to drive the movement of the stopper 21, the centering device 2 also includes a follower 25. One end of the follower 25 is connected to the end of the guide rod 22 near the center of the positioning base 1, and the other end of the follower 25 abuts the edge of the cam 31. Thus, when the cam 31 rotates, when the protrusion 311 of the cam 31 abuts the follower 25, the follower 25 drives the guide rod 22 and the stopper 21 away from the center of the positioning base 1, at which time the spring 23 is in a compressed state; when the groove 312 of the cam 31 abuts the follower 25, the spring 23 releases its elastic force, driving the guide rod 22, the follower 25, and the stopper 21 to move toward the center of the positioning base 1.

[0073] In the embodiment of the present application, the follower 25 includes a guide wheel 252 and a connecting rod 251. A movable groove is formed on the lower surface of the positioning base 1, which is connected to the radial hole. The connecting rod 251 passes through the movable groove in a vertical direction and can move horizontally within the movable groove. One end of the connecting rod 251 is fixedly connected to the end of the guide rod 22 located in the radial hole. The fixing method is not restrictive and can be threaded, plugged, welded, or glued. The other end of the connecting rod 251 is connected to the center of the guide wheel 252. The axis of the guide wheel 252 is parallel to the axis of the cam 31. The connection structure between the connecting shaft and the guide wheel 252 is not restrictive and can be fixed or rotatable. A rotatable connection is preferably used to reduce friction between the cam 31 and the follower 25 and improve stability. The guide wheel 252 abuts the cam 31. This design allows the cam 31 to rotate and drive the guide wheel 252 to move away from the center of the positioning base 1.

[0074] With the above structure, when a wafer needs to be placed, the cam 31 is rotated so that each protrusion 311 of the cam 31 abuts each guide wheel 252, causing the guide wheels 252 to rotate and move linearly away from the center of the positioning base 1. This linear motion causes the guide wheels 252 to move the guide rods 22 via the connecting rods 251, and the guide rods 22 in turn move the stoppers 21, moving each stopper 21 away from the center of the positioning base 1. This increases the area between the stoppers 21, making it easier for workers to place wafers on the positioning base 1.

[0075] When the limiter 21 is away from the positioning base 1, the elastic member is in a compressed state. As the raised portion 311 of the cam 31 gradually moves away from the guide wheel 252, the elastic member releases its elastic force, driving the guide rod 22, the limiter 21 and the follower 25 to move toward the center of the positioning base 1, and the guide wheel 252 abuts against the groove portion 312 of the cam 31. This multi-directional retraction process causes multiple limiters 21 to simultaneously retract toward the center of the positioning base 1, ultimately causing the center of the wafer and the center of the positioning base 1 to be on the same axis. This design achieves the centering effect on the wafer and improves the accuracy of subsequent wafer processing.

[0076] Furthermore, the method of rotating the cam 31 is relatively flexible. The cam 31 can be rotated manually or with the help of a device that can provide rotational power to the cam 31, such as a motor.

[0077] like Figure 4 and Figure 5 As shown, as a preferred solution of the embodiment of the present application, the synchronous drive device 3 in the embodiment of the present application further includes a rotation drive device 32 for providing rotational power to the cam 31. The rotation drive device 32 includes:

[0078] The gear 321 coincides with the axis of the cam 31 and is fixedly connected to the lower surface of the cam 31;

[0079] The rack 322 moves in the horizontal direction and meshes with the gear 321;

[0080] The driving member 323 can drive the rack 322 to move linearly in the horizontal direction, such as a cylinder, a linear motor, a hydraulic cylinder, etc.; in the embodiment of the present application, a cylinder is preferably used as the driving member 323.

[0081] The driving member 323 drives the rack 322 to move linearly, so that the rack 322 engages with the gear 321, drives the gear 321 to rotate, and the gear 321 drives the cam 31 to rotate, thereby achieving the effect of providing rotational power to the cam 31.

[0082] Furthermore, in order to improve the stability of the connection between the gear 321 and the cam 31, and to ensure that the gear 321 is subjected to a more uniform force when providing a rotational force to the cam 31, the rotation axes of the cam 31 and the gear 321 are located on the same vertical axis, and a boss 313 is fixedly provided on the lower surface of the cam 31. The center of the gear 321 is a hollow structure, and the boss 313 is located at the center of the gear 321 and is fixedly connected to the circumferential inner wall of the gear 321. A bearing seat 8 is provided in the boss 313, and the central axis 51 passes through the center of the bearing seat 8. Bearings are installed between the boss 313 and the bearing seat 8 and between the bearing seat 8 and the central axis 51. As a preferred embodiment of the present application, the bearing installed between the boss 313 and the bearing seat 8 is a needle roller bearing 81, and the bearing installed between the bearing seat 8 and the central axis 51 is a deep groove ball bearing 82.

[0083] In the embodiment of the present application, the centering and edge-finding mechanism further includes a base plate 4, the upper surface of which is fixedly provided with a bracket 41, the driving member 323 being mounted and fixed to the bracket 41, and the bracket 41 being used to provide good stability for the driving member 323. A guide rail base 42 is fixedly provided on the upper surface of the base plate 4 in the vertical direction, and a linear guide rail 421 is fixedly provided on the guide rail base 42 along the length direction of the rack 322 on the side facing the rack 322, and the side of the rack 322 facing away from the gear 321 is slidably connected to the linear guide rail 421. The bottom of the bearing seat 8 is fixedly mounted and fixed to the upper surface of the base. The body of the drive motor is also fixedly mounted and fixed to the base, thereby improving the stability of the overall structure of the device.

[0084] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the embodiments of the present invention. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not covered by this application. The specification and embodiments are intended to be exemplary only, and the true scope and spirit of the present invention are indicated by the appended claims.

Claims

1. An edge-finding mechanism for finding the positioning edge of a wafer, characterized in that: include: A positioning base (1) is used to place the wafer, the center of the positioning base (1) and the center of the wafer are located on the same axis, the positioning base (1) is provided with at least two blowing holes (11) suitable for blowing air upward, the at least two blowing holes (11) are suitable for connecting to an air source, the linear profile formed by the center line of the at least two blowing holes (11) is consistent with the linear profile of the positioning edge, and the at least two blowing holes (11) are located at positions on the positioning base (1) corresponding to the position of the positioning edge of the expected wafer orientation; A detection mechanism is provided corresponding to the at least two air blowing holes (11) and is used to detect the air pressure value in the air blowing holes (11). When it is detected that the air pressure values of the at least two air blowing holes (11) are reduced and the reduced air pressure values are consistent, the positioning edge of the wafer and the linear contours formed by the at least two air blowing holes (11) are equidistant lines from each other.

2. The edge-finding mechanism according to claim 1, characterized in that: The positioning edge is a short edge formed on the edge of the wafer; the linear profile formed by the center line connecting the at least two blowing holes (11) is a straight line.

3. The edge-finding mechanism according to claim 1, characterized in that: The positioning base (1) is a hollow structure; the edge-finding mechanism further comprises: A vacuum suction cup (5) is rotatably arranged at the hollow structure of the positioning base (1), the vacuum suction cup (5) is used to abut against the lower surface of the wafer, and the center of the vacuum suction cup (5) and the center of the wafer are located on the same axis; A central shaft (51) is located below the vacuum suction cup (5) and one end of which is fixedly connected to the vacuum suction cup (5); the axis of the central shaft (51) is coaxial with the center of the vacuum suction cup (5); an air passage is formed inside the central shaft (51), and the air passage is connected to the vacuum suction cup (5); A rotary drive mechanism is used to drive the central axis (51) to rotate; the rotary drive mechanism is configured to drive the central axis (51) to rotate when the detection mechanism detects that the air pressure values of the at least two blowing holes (11) have not decreased or the reduced air pressure values are inconsistent, and stop driving when the detection mechanism detects that the air pressure values of the at least two blowing holes (11) have decreased to the same value.

4. The edge-finding mechanism according to claim 3, characterized in that: The detection mechanism includes a pressure switch (9) for detecting the air pressure in each of the blowing holes (11); when the blowing holes (11) are blocked by the wafer, the pressure switch (9) generates pressure and the pressure value reaches a maximum state, and the rotation drive mechanism starts to drive the central axis (51) to rotate in response to the pressure value in the maximum state; when the linear contours of all the blowing holes (11) are flush with the positioning edge of the wafer, the pressure values of all the pressure switches (9) are reduced to the same value, and the rotation drive mechanism stops driving the central axis (51) to rotate.

5. The edge-finding mechanism according to claim 4, characterized in that: The detection mechanism also includes a quick-connect connector and an air duct, the pressure switch (9) is installed on the air duct, one end of the air duct is connected to the air hole (11) through the quick-connect connector, and the other end of the air duct is connected to the air source.

6. The edge-finding mechanism according to claim 3, characterized in that: The rotary drive mechanism comprises a rotary power output device (6) for providing rotary power and a transmission device (7) for transmitting the rotary power generated by the rotary power output device (6) to the central shaft (51).

7. The edge-finding mechanism according to claim 6, characterized in that: The rotary power output device (6) is a driving motor. The transmission device (7) comprises a driving wheel (71), a driven wheel (72) and a synchronous belt (73). The driving wheel (71) is located on one side of the central shaft (51), and its rotation axis is parallel to the length direction of the central shaft (51). The output shaft of the driving motor is fixedly connected to the center of the driving wheel (71); the driven wheel (72) and the driving wheel (71) are located at the same horizontal height. The central shaft (51) passes through the center of the driven wheel (72) and is fixedly connected to the driven wheel (72). The synchronous belt (73) is wrapped around the driving wheel (71) and the driven wheel (72).

8. A centering and edge-finding mechanism, characterized in that: It comprises the edge-finding mechanism of any one of claims 1 to 7; and further comprises a centering mechanism, wherein the centering mechanism is configured to make the center of the wafer and the center of the positioning base (1) on the same axis.

9. A centering and edge-finding mechanism according to claim 8, characterized in that: The centering mechanism comprises: At least three groups of centering devices (2) are arranged around the positioning base (1) in an interval-surrounding manner, and each group of centering devices (2) is equidistant from the center of the positioning base (1); The synchronous driving device (3) is configured to drive the at least three sets of centering devices (2) to move the same distance simultaneously in a direction close to or away from the center of the positioning base (1); when driving the at least three sets of centering devices (2) to move the same distance simultaneously in a direction close to the center of the positioning base (1), the centering device (2) pushes the wafer so that the center of the wafer and the center of the positioning base (1) are located on the same axis.

10. A centering and edge-finding mechanism according to claim 9, characterized in that: The side wall of the positioning base (1) is provided with radial channels corresponding to the at least three sets of centering devices (2), and the radial channels face the center of the positioning base (1); The centering device (2) comprises: A limiting member (21) having a limiting surface facing the center of the positioning base (1) for pushing the wafer; A guide member is movably mounted in the radial channel, wherein one end of the guide member away from the center of the positioning base (1) extends out of the positioning base (1), and the limit member (21) is mounted on the end; and one end of the guide member close to the positioning base (1) is configured to be driven by the synchronous drive device (3) so that the guide member can slide back and forth in the radial channel.

11. A centering and edge-finding mechanism according to claim 10, characterized in that: The radial channel is a radial hole; the guide member is a guide rod (22) inserted into the radial hole; The centering device (2) further comprises a spring (23) and a spring baffle (24), wherein the spring (23) is sleeved on the guide rod (22), and the spring baffle (24) is fixed at an opening of the radial hole on a side away from the center of the positioning base (1), and one end of the spring (23) close to the center of the positioning base (1) is connected to the guide rod (22), and one end of the spring (23) away from the positioning base (1) abuts against the spring baffle (24); One end of the guide rod (22) away from the center of the positioning base (1) passes through the spring baffle (24) and extends out of the positioning base (1).

12. A centering and edge-finding mechanism according to claim 11, characterized in that: The synchronous driving device (3) comprises a cam (31) and a rotation driving device (32), wherein the rotation driving device (32) is used to drive the cam (31) to rotate; the center of the cam (31) is coaxial with the center of the positioning base (1); the edge of the cam (31) is provided with at least three protrusions (311) corresponding to at least three guide rods (22); at least three grooves (312) are formed between the at least three protrusions (311); when the cam (31) rotates, the protrusions (311) are used to push the guide rod (22) to overcome the elastic force of the spring (23) and move in a direction away from the center of the positioning base (1); the grooves (312) are used to enable the guide rod (22) to move in a direction close to the center of the positioning base (1) under the action of the release of the elastic force of the spring (23).

13. A centering and edge-finding mechanism according to claim 12, characterized in that: The centering device (2) further comprises a follower (25) mounted on one end of the guide rod (22) close to the center of the positioning base (1); the follower (25) abuts against the edge of the cam (31); and the cam (31) drives the guide rod (22) to move via the follower (25).

14. A centering and edge-finding mechanism according to claim 13, characterized in that: The follower (25) comprises: A connecting rod (251), one end of which is fixedly connected to the guide rod (22), and an extending direction of the connecting rod (251) is parallel to the axis of the cam (31); The guide wheel (252) is mounted on the other end of the connecting rod (251), and the edge of the guide wheel (252) abuts against the edge of the cam (31).

15. The centering and edge-finding mechanism according to claim 12, characterized in that: It also includes a rotation drive device (32) for driving the cam (31) to rotate, and the rotation drive device (32) further includes: a gear (321) coinciding with the axis of the cam (31) and fixedly connected to the cam (31); a rack (322) meshing with the gear (321); The driving member (323) is used to drive the rack (322) to move linearly in the horizontal direction.

16. A centering and edge-finding mechanism according to claim 15, characterized in that: The central shaft (51) passes through the centers of the gear (321) and the cam (31) in sequence along the vertical direction, and the central shaft (51) is rotatably connected to the gear (321) and the cam (31); a boss (313) is fixedly provided on the lower surface of the cam (31); the center of the gear (321) is a hollow structure; the boss (313) is located inside the gear (321) and is fixedly connected to the gear (321); a bearing seat (8) is provided between the boss (313) and the central shaft (51); and bearings are installed on the outer side and the inner side of the bearing seat (8) between the boss (313) and the central shaft (51), respectively.

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