A chuck

Abstract

The present application relates to the technical field of semiconductor detection, and particularly relates to a chuck, comprising: a main body part, the main body part has a bearing surface and a center through hole, the bearing surface comprises a first area and a second area surrounding the first area; a boss structure located in the first area and a sealing structure located in the second area; wherein the boss structure comprises a plurality of circumferential boss groups and a plurality of radial boss groups, each circumferential boss group comprises a plurality of first bosses arranged along a corresponding circumferential interval, the corresponding circumferential radius of each circumferential boss group is different and concentric with the center through hole, the radial boss group is in a curve type, each radial boss group extends from the center through hole to the second area, and each radial boss group is spaced apart, and each radial boss group comprises a plurality of second bosses arranged at intervals along the extension direction thereof. The chuck provided by the present application is beneficial to realizing higher adsorption force adsorption of the wafer, and ensures that the wafer has higher flatness.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of semiconductor detection, and particularly relates to a chuck. BACKGROUND

[0002] In a overlay measurement process, the measurement speed needs to be matched with the process speed of a lithography machine, and the measurement accuracy is sub-nanometer level to correct the lithography process. In the measurement process, the wafer needs to be placed below an optical detection system, and the wafer is driven to move at a high acceleration or deceleration by the chuck. After the wafer is moved to a position, the wafer needs to quickly reach a nanometer level of position stability. It is found through analysis that for a process below 28 nm node, higher measurement speed and measurement accuracy are needed. Therefore, the platform for driving the wafer to move needs higher acceleration and higher position stability. At present, the acceleration of the platform for driving the wafer to move is required to be at least 2g (g is the acceleration of gravity), and the in-position stability of the wafer in a static state is required to be less than 1 nm.

[0003] However, in recent years, with the rise of advanced packaging, the advanced packaging process leads to larger and more complex wafer warping. For the chuck, it needs to be compatible with wafers with larger warping. In addition, in the overlay measurement process, the poor flatness of the wafer surface after adsorption will also negatively affect the measurement accuracy. Therefore, it is urgent to design a chuck that can be compatible with large warping, high flatness after adsorption, high acceleration movement and high in-position stability. SUMMARY

[0004] Therefore, the application aims to provide a chuck which is beneficial to adsorb the wafer with higher adsorption force and ensure that the wafer has higher flatness and stability.

[0005] To achieve the above-mentioned purpose, the technical scheme of the application is as follows:

[0006] The application provides a chuck, which comprises a main body part, the main body part has a bearing surface and a center through hole, the bearing surface comprises a first area and a second area surrounding the first area; a boss structure located in the first area and a sealing structure located in the second area; wherein the boss structure comprises a plurality of circumferential boss groups and a plurality of radial boss groups, each circumferential boss group comprises a plurality of first bosses arranged along the corresponding circumferential direction, the corresponding circumferential radius of each circumferential boss group is different and the center through hole is concentric, the radial boss group is in a curve shape, each radial boss group extends from the center through hole to the second area, and each radial boss group is spaced apart, and each radial boss group comprises a plurality of second bosses arranged along the extension direction.

[0007] Further, each radial boss group comprises a first sub-boss group and a second sub-boss group arranged along the extension direction thereof, the first sub-boss group comprises a plurality of second bosses, the second sub-boss group comprises a plurality of second bosses, the starting point of each first sub-boss group is located on a first preset circle, the ending point of each first sub-boss group is located on a second preset circle, the starting point of each second sub-boss group is located on the second preset circle, and the ending point of each second sub-boss group is located on a third preset circle, the first preset circle, the second preset circle and the third preset circle have the same center as the center through hole, and the radius of the third preset circle is greater than the radius of the second preset circle, and the radius of the second preset circle is greater than the radius of the first preset circle.

[0008] Further, in each radial boss group, the ending point of the first sub-boss group coincides with the starting point of the second sub-boss group.

[0009] Further, in each radial boss group, the ending point of the first sub-boss group coincides with the starting point of the second sub-boss group.

[0010] Further, in each radial boss group, the direction of the line connecting the starting point of the first sub-boss group and the ending point of the first sub-boss group is defined as the first direction, the direction of the line connecting the starting point of the first sub-boss group and the starting point of the second sub-boss group is defined as the second direction, and the included angle between the first direction and the second direction is within a first range, and the first range is 20°-40°.

[0011] Further, each radial boss group comprises a first sub-boss group and a second sub-boss group arranged along the extension direction thereof, the first sub-boss group comprises a plurality of second bosses, the second sub-boss group comprises a plurality of second bosses, the starting point of each first sub-boss group is located on a first preset circle, the ending point of each first sub-boss group is located on a second preset circle, the starting point of each second sub-boss group is located on a fourth preset circle, and the ending point of each second sub-boss group is located on a third preset circle, the first preset circle, the second preset circle, the third preset circle and the fourth preset circle have the same center as the center through hole; wherein the radius of the first preset circle is smaller than the radius of the fourth preset circle, the radius of the fourth preset circle is smaller than the radius of the second preset circle, the radius of the second preset circle is smaller than the radius of the third preset circle, and in each radial boss group, the first sub-boss group and the second sub-boss group are staggered in the radial direction of the second preset circle.

[0012] Further, in each radial boss group, the direction of the line connecting the starting point of the first sub-boss group and the ending point of the first sub-boss group is defined as the first direction, the direction of the line connecting the starting point of the first sub-boss group and the ending point of the second sub-boss group is defined as the third direction, and the included angle between the first direction and the third direction is within a second range, and the second range is 20°-40°.

[0013] Further, the inner part of the main body part has a plurality of spaced hollow regions.

[0014] Further, the height of the sealing structure is not less than the height of the boss structure.

[0015] Further, the sealing structure is annular, and the inner circle of the sealing structure is concentric with the center through hole.

[0016] Further, the chuck is an integral structure.

[0017] Further, the chuck is prepared by a 3D printing process.

[0018] Compared with the prior art, the chuck provided by the application has the following beneficial effects: the chuck includes a main body, the main body is internally designed with a plurality of spaced grid, which not only helps to reduce the weight of the chuck but also ensures that the chuck has high structural strength, the bearing surface of the main body is provided with a sealing structure and a boss structure located in the inner circle of the sealing structure, the boss structure includes a plurality of circumferential boss groups and a plurality of radial boss groups, each circumferential boss group includes a plurality of first bosses arranged along the circumference, and each radial boss group includes a plurality of second bosses arranged along a curve, when the wafer is adsorbed, the plurality of circumferential boss groups, the plurality of radial boss groups and the sealing structure cooperate together, and by using the vacuum adsorption principle, high adsorption force and high flatness adsorption can be realized for the bowl-shaped warped wafer, the umbrella-shaped warped wafer and the wave-shaped warped wafer, which helps to improve the measurement accuracy and measurement accuracy of overlay measurement. BRIEF DESCRIPTION OF DRAWINGS

[0019] The drawings constituting a part of this application provide further understanding of the application, the schematic embodiments of the application and the description thereof are used to explain the application, and do not constitute improper limitation of the application. In the drawings:

[0020] Figure 1 Part structure schematic view of the chuck described in the embodiments of the application;

[0021] Figure 2 Top view of a chuck described in the embodiments of the application;

[0022] Figure 3 Top view of another chuck described in the embodiments of the application;

[0023] Figure 4 Top view of still another chuck described in the embodiments of the application. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the application more clear, the application is further described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the application, and do not constitute limitation of the application.

[0025] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0026] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0027] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0028] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0029] Reference Figures 1 to 4 The present application provides a chuck, comprising: a main body portion having a load surface 101 and a central through hole 130, the load surface 101 comprising a first region and a second region surrounding the first region; a boss structure located in the first region and a sealing structure 102 located in the second region; wherein the boss structure comprises a plurality of circumferential boss groups and a plurality of radial boss groups, each circumferential boss group comprises a plurality of first bosses 111 arranged at intervals along a corresponding circumferential direction, the corresponding circumferential radius of each circumferential boss group is different and concentric with the central through hole 130, the radial boss group is in a curved shape, each radial boss group extends from the central through hole 130 to the second region, and each radial boss group is spaced apart, and each radial boss group comprises a plurality of second bosses 112 arranged at intervals along the extension direction thereof.

[0030] In some embodiments, the height of the sealing structure 102 is not less than the height of the boss structure.

[0031] In some embodiments, the sealing structure 102 is annular, and the inner circle of the sealing structure 102 is concentric with the center through hole 130, or in other words, the circumferential boss group corresponding to the inner circle of the sealing structure 102 is concentric.

[0032] It should be noted that the chuck is used to adsorb the wafer and move the wafer, the boss structure is located in the inner circle of the sealing structure 102, and the side of the boss structure and the sealing structure 102 away from the bearing surface 101 is used to bear the wafer. When the chuck adsorbs the wafer, a vacuum is formed between the side of the wafer facing the chuck, the sealing structure 102 and the bearing surface 101, thereby forming a negative pressure adsorption on the wafer, and the boss structure supports the wafer.

[0033] In some embodiments, the center through hole 130 penetrates the main body in the thickness direction of the main body.

[0034] For a bowl-shaped warped wafer, when the wafer is placed on the chuck and the chuck does not adsorb the wafer, the central region of the wafer is concave in the direction of the chuck, and the edge region of the wafer is warped in the direction away from the chuck relative to the central region. When the center through hole 130 starts to suck the gas between the wafer and the chuck, a vacuum can be established from the inner circle of the circumferential boss group closest to the center through hole 130, and the vacuum gradually extends to the sealing structure 102 at the outermost circle. The adsorption force can be gradually formed from the central region of the wafer to the edge of the wafer, and in this process, the radial boss group guides the airflow, which not only makes the vacuum form faster, but also makes the radial boss group extend along the radial curve, so that the boss structure not only contacts the circular region on the surface of the wafer, but also contacts the radial region on the surface of the wafer. This can reduce the gas leakage phenomenon caused by the inconsistent height of the circular region on the surface of the wafer, and the curved radial boss group also reduces the gas leakage phenomenon caused by the inconsistent height of the radial region on the surface of the wafer, thereby achieving high adsorption force and high flatness adsorption.

[0035] For an umbrella-shaped warped wafer, since the edge of the wafer first contacts the sealing structure 102, the vacuum is also easier to establish. The radial boss group extends along the radial curve, so that the boss structure not only contacts the circular region on the surface of the wafer, but also contacts the radial region on the surface of the wafer. This can reduce the gas leakage phenomenon caused by the inconsistent height of the circular region on the surface of the wafer, and the curved radial boss group also reduces the gas leakage phenomenon caused by the inconsistent height of the radial region on the surface of the wafer, thereby achieving high adsorption force and high flatness adsorption. The uniform distribution of the boss structure can also ensure high flatness adsorption.

[0036] For the wave-shaped warped wafer, if the center region of the wafer is concave to the chuck, the principle of suction is similar to that of the bowl-shaped warped wafer, if the center region of the wafer is convex to the chuck, the principle of suction is similar to that of the umbrella-shaped warped wafer, and the vacuum of the center region of the wafer is easier to establish, and the subsequent vacuum establishment process is similar to that of the bowl-shaped warped wafer.

[0037] In practical applications, different chucks with different designs of the boss structure can be used according to the warping type of the wafer. In some examples, for the bowl-shaped warped wafer, any one of the chucks shown in Figures 2 to 4 may be used; for the umbrella-shaped warped wafer, any one of the chucks shown in Figures 2 to 4 may be used; and for the wave-shaped warped wafer, the chuck shown in Figure 2 or Figure 4 may be used.

[0038] In some embodiments, the first boss 111 has a long strip shape in the orthographic projection on the bearing surface 101, and each first boss 111 extends along the corresponding circumferential direction; and the second boss 112 has a long strip shape in the orthographic projection on the bearing surface 101, and each second boss 112 extends along the extension direction of the corresponding radial boss group. Compared with the point-shaped boss, the strip-shaped boss can direct the flow direction of the airflow in a specific arrangement manner, and the strip-shaped boss has a better support effect.

[0039] In some embodiments, the cross section of the first boss 111 along the thickness direction can be trapezoidal. In this way, the edge of the boss can be prevented from being too sharp, and the scratching phenomenon caused by the wafer can be avoided to a certain extent.

[0040] In some embodiments, the main body further has a plurality of thimble holes 131 and a plurality of mounting holes 132, the thimble holes 131 and the mounting holes 132 all penetrate the main body along the thickness direction of the main body, the thimble holes 131 are used to set up liftable thimbles, the thimbles are used to lift the wafer, so that the wafer can be placed on the chuck by the robot, after the wafer is placed on the chuck by the robot, the thimbles are lowered, so that the wafer falls on the chuck, and the mounting holes 132 are used to set up mounting members, the mounting members are used to mount the chuck to a driving mechanism, the driving mechanism is used to drive the chuck to rotate along the axial direction of the chuck, and is used to drive the chuck to translate along the direction parallel to the bearing surface 101.

[0041] In one specific embodiment, the main body has 3 pin holes 131 and 3 mounting holes 132, the center line of the 3 pin holes 131 forms a first equilateral triangle, the center of the first equilateral triangle coincides with the center of the circle, the center line of the 3 mounting holes 132 forms a second equilateral triangle, the center of the second equilateral triangle coincides with the center of the circle, and the side length of the first equilateral triangle is greater than the side length of the second equilateral triangle.

[0042] In some embodiments, the plurality of circumferential boss groups are evenly arranged between the center through hole 130 and the sealing structure 102.

[0043] Reference Figure 2 and Figure 3 In some embodiments, each radial boss group includes a first sub-boss group and a second sub-boss group arranged along the extension direction thereof, the first sub-boss group includes a plurality of second bosses 112, the second sub-boss group includes a plurality of second bosses 112, the starting point of each first sub-boss group is located on a first preset circle, the ending point of each first sub-boss group is located on a second preset circle, the starting point of each second sub-boss group is located on the second preset circle, and the ending point of each second sub-boss group is located on a third preset circle, the first preset circle, the second preset circle, and the third preset circle have the same center as the center through hole 130, and the radius of the third preset circle is greater than the radius of the second preset circle, and the radius of the second preset circle is greater than the radius of the first preset circle.

[0044] In some embodiments, the radius of the first preset circle can be in the range of 8mm-16mm, for example, the radius of the first preset circle can be 12mm.

[0045] In one specific embodiment, the size of the chuck corresponds to a 12-inch wafer, the radius of the second preset circle can be in the range of 80mm-110mm, and the radius of the third preset circle can be in the range of 135mm-145mm. It can be understood that in other embodiments, the size of the chuck can also correspond to wafers of other sizes, and the radius of the second preset circle and the radius of the third preset circle can be determined according to the actual warping state and topography of the wafer.

[0046] Reference Figure 3 In some embodiments, in each radial boss group, the ending point of the first sub-boss group coincides with the starting point of the second sub-boss group.

[0047] In some examples, the number of radial boss groups is N, N can be in the range of 8-12, and N radial boss groups evenly divide the area between the first preset circle and the third preset circle into N areas of the same size.

[0048] Reference Figure 2 In some embodiments, in each radial boss group, the ending point of the first sub-boss group and the starting point of the second sub-boss group are staggered, and it should be noted that,Figure 2 In some examples, the number of the radial boss groups is N, N is in the range of 8-12, the N first sub-boss groups evenly divide the area between the first preset circle and the second preset circle into N areas of the same size, and the N second sub-boss groups also evenly divide the area between the second preset circle and the third preset circle into N areas of the same size.

[0049] In some examples, the number of the radial boss groups is N, N is in the range of 8-12, the N first sub-boss groups evenly divide the area between the first preset circle and the second preset circle into N areas of the same size, and the N second sub-boss groups also evenly divide the area between the second preset circle and the third preset circle into N areas of the same size.

[0050] In some examples, the number of the circumferential boss groups can be in the range of 8-12.

[0051] In some examples, the number of the radial boss groups is N, N is in the range of 8-12, and N is an even number, the number of the first bosses 111 in the circumferential boss group located at the innermost circle is N / 2, the number of the first bosses 111 in the circumferential boss group located at the outermost circle is 2N or 3N, and the number of the first bosses 111 in the remaining circumferential boss groups is N or 2N.

[0052] It can be understood that the number of the circumferential boss groups, the number of the radial boss groups, and the number of the first bosses 111 are only examples, and when designing the boss structure, the number of the circumferential boss groups, the number of the radial boss groups, the number of the first bosses 111, and the number of the second bosses 112 can be determined according to the actual warping state and the topography of the wafer.

[0053] In some embodiments, referring to Figure 2 , in each radial boss group, the direction of the line connecting the start point of the first sub-boss group and the end point of the first sub-boss group is defined as the first direction (the direction of the green arrow in Figure 2 ), and the direction of the line connecting the start point of the first sub-boss group and the start point of the second sub-boss group is defined as the second direction (the direction of the red arrow in Figure 2 ), the included angle between the first direction and the second direction is in a first range, and the first range is 20°-40°. In some examples, the included angle between the first direction and the second direction can be 25°, 30°, or 35°.

[0054] Referring to Figure 4 , in some embodiments, each radial boss group includes a first sub-boss group and a second sub-boss group arranged along the extension direction thereof, and it should be noted that Figure 4In the specific embodiment, a first sub-boss group is circled by the green dashed line, and a second sub-boss group is circled by the red dashed line. The first sub-boss group includes a plurality of second bosses 112, and the second sub-boss group includes a plurality of second bosses 112. The starting point of each first sub-boss group is located on the first preset circle, and the ending point of each first sub-boss group is located on the second preset circle. The starting point of each second sub-boss group is located on the fourth preset circle, and the ending point of each second sub-boss group is located on the third preset circle. The first preset circle, the second preset circle, the third preset circle, and the fourth preset circle have the same center as the center through hole 130. The radius of the first preset circle is smaller than the radius of the fourth preset circle, the radius of the fourth preset circle is smaller than the radius of the second preset circle, the radius of the second preset circle is smaller than the radius of the third preset circle, and the first sub-boss group and the second sub-boss group in each radial boss group are staggered in the radial direction of the second preset circle.

[0055] In some embodiments, the radius of the first preset circle can be in the range of 8mm to 16mm, for example, the radius of the first preset circle can be 12mm.

[0056] In a specific embodiment, the size of the chuck corresponds to a 12-inch wafer, the radius of the second preset circle is in the range of 40mm to 90mm, the radius of the third preset circle is in the range of 135mm to 145mm, and the radius of the fourth preset circle is in the range of 100mm to 130mm. It can be understood that in other embodiments, the size of the chuck can also correspond to wafers of other sizes, and the radius of the first preset circle, the radius of the second preset circle, and the radius of the third preset circle can be determined according to the actual warping state and topography of the wafer.

[0057] In some embodiments, with reference to Figure 4 , in the radial boss group, the direction of the line connecting the starting point of the first sub-boss group and the ending point of the first sub-boss group is defined as the first direction (the direction of the green arrow in Figure 4 , and the direction of the line connecting the starting point of the first sub-boss group and the ending point of the second sub-boss group is defined as the third direction (the direction of the red arrow in Figure 4 ). The included angle between the first direction and the third direction is in a second range, and the second range is 20° to 40°. In some examples, the included angle between the first direction and the third direction can be 25°, 30°, or 35°.

[0058] In some embodiments, the interior of the main body portion has a plurality of spaced-apart hollowed-out regions.

[0059] In some embodiments, the hollowed-out regions can be closed grids 103.

[0060] In some embodiments, the plurality of grids 103 are arrayed in the main body portion in a direction parallel to the bearing surface 101.

[0061] In some embodiments, the main body part comprises a bottom plate 121, a top plate 122, a side plate 120 and a plurality of intermediate partition plates 123, the top plate 122 is arranged opposite and parallel to the bottom plate 121, the surface of the top plate 122 away from the bottom plate 121 is the bearing surface 101, the side plate 120 is perpendicular to the top plate 122, and the two sides of the side plate 120 are connected with the edges of the top plate 122 and the bottom plate 121 respectively, the top plate 122, the bottom plate 121 and the side plate 120 enclose a cavity, the intermediate partition plates 123 are arranged in the cavity, the intermediate partition plates 123 are perpendicular to the top plate 122, and the plurality of intermediate partition plates 123 divide the cavity into a plurality of grids 103. In this way, the weight of the chuck can be reduced, and the rigidity of the chuck can be improved.

[0062] In some embodiments, the chuck is an integrally formed structure.

[0063] In some embodiments, the chuck is prepared by a 3D printing process.

[0064] Compared with a conventional chuck with the same size, the inside of the main body part of the chuck has a plurality of spaced hollow regions, which reduces the weight of the chuck by 50%, and increases the natural resonant frequency by 30%. The boss structure can improve the flatness of the wafer by 50% after the wafer is adsorbed by the chuck, and the chuck has higher rigidity, better stress release capability and smaller thermal deformation.

[0065] The chuck provided by the present application supports the wafer by using a boss structure comprising a plurality of small bosses, reduces the contact area between the chuck and the wafer, and has smaller particle pollution and metal pollution on the back of the wafer. The first bosses 111 arranged along the circumference form a circumferential boss group, the circumferences of the plurality of circumferential boss groups have the same center, and the radial boss group extending along the radial direction can guide the airflow at the beginning of the adsorption. For the wafer with bowl-shaped warping, a stronger adsorption force is established in the central area first, and the adsorption force is gradually radiated to the edge of the wafer to form adsorption on the whole wafer. For the wafer with wave-shaped warping and the wafer with umbrella-shaped warping, higher adsorption capacity can also be achieved by guiding the vacuum airflow.

[0066] It should be understood that the various forms of flow shown above can be reordered, added or deleted steps. For example, the steps described in the present disclosure can be executed in parallel, in sequence or in different order, as long as the desired results of the technical solutions disclosed in the present disclosure can be achieved, which is not limited herein.

[0067] The above detailed description does not limit the scope of the application. Various modifications, combinations, sub-combinations and alternatives can be made to the detailed embodiment within the scope of the application. Any modification, equivalent replacement and improvement made without departing from the spirit and principle of the application shall fall within the scope of the application.

Claims

1. A chuck, characterized in that, include: The main body has a bearing surface and a central through hole. The bearing surface includes a first region and a second region surrounding the first region. The interior of the main body has a plurality of spaced-apart hollow regions. A boss structure located in the first region and a sealing structure located in the second region; The boss structure includes multiple circumferential boss groups and multiple radial boss groups. Each circumferential boss group includes multiple first bosses arranged at intervals along the corresponding circumference. The circumferential boss groups have different circumferential radii and are concentric with the central through hole. The radial boss groups are curved and extend from the central through hole to the second region. Each radial boss group is spaced apart from the others. Each radial boss group includes multiple second bosses arranged at intervals along its extension direction.

2. The chuck according to claim 1, characterized in that, Each radial boss group includes a first sub-boss group and a second sub-boss group arranged along its extension direction. The first sub-boss group includes a plurality of second bosses, and the second sub-boss group includes a plurality of second bosses. The starting point of each first sub-boss group is located on a first preset circle, and the ending point of each first sub-boss group is located on a second preset circle. The starting point of each second sub-boss group is located on a second preset circle, and the ending point of each second sub-boss group is located on a third preset circle. The first preset circle, the second preset circle, and the third preset circle are all concentric with the central through hole, and the radius of the third preset circle is greater than the radius of the second preset circle, and the radius of the second preset circle is greater than the radius of the first preset circle.

3. The chuck according to claim 2, characterized in that, In each of the radial boss groups, the end point of the first sub-boss group coincides with the starting point of the second sub-boss group.

4. The chuck according to claim 2, characterized in that, In each of the radial boss groups, the end point of the first sub-boss group and the starting point of the second sub-boss group are offset from each other.

5. The chuck according to claim 4, characterized in that, In each of the radial boss groups, the direction of the line connecting the starting point of the first sub-boss group and the ending point of the first sub-boss group is defined as the first direction, and the direction of the line connecting the starting point of the first sub-boss group and the starting point of the second sub-boss group is defined as the second direction. The angle between the first direction and the second direction is within a first range, which is 20°~40°.

6. The chuck according to claim 1, characterized in that, Each of the radial boss groups includes a first sub-boss group and a second sub-boss group arranged along its extension direction. The first sub-boss group includes a plurality of second bosses, and the second sub-boss group includes a plurality of second bosses. The starting point of each first sub-boss group is located on a first preset circle, and the ending point of each first sub-boss group is located on a second preset circle. The starting point of each second sub-boss group is located on a fourth preset circle, and the ending point of each second sub-boss group is located on a third preset circle. The first preset circle, the second preset circle, the third preset circle, and the fourth preset circle are all concentric with the central through hole. Wherein, the radius of the first preset circle is smaller than the radius of the fourth preset circle, the radius of the fourth preset circle is smaller than the radius of the second preset circle, the radius of the second preset circle is smaller than the radius of the third preset circle, and in each of the radial boss groups, the first sub-boss group and the second sub-boss group are offset from each other in the radial direction of the second preset circle.

7. The chuck according to claim 6, characterized in that, In the radial boss group, the direction of the line connecting the starting point and the ending point of the first sub-boss group is defined as the first direction, and the direction of the line connecting the starting point and the ending point of the second sub-boss group is defined as the third direction. The angle between the first direction and the third direction is within a second range, which is 20°~40°.

8. The chuck according to claim 1, characterized in that, The height of the sealing structure is not less than the height of the boss structure.

9. The chuck according to claim 1, characterized in that, The sealing structure is annular, and the inner ring of the sealing structure is concentric with the central through hole.

10. The chuck according to claim 1, characterized in that, The chuck is a one-piece molded structure.

11. The chuck according to any one of claims 1 to 10, characterized in that, The chuck is manufactured using 3D printing technology.

Images