Top grinding structure of wafer grinding machine and wafer grinding machine

Abstract

The invention relates to a top grinding structure of a wafer grinding miller and the wafer grinding miller, and relates to the technical field of the wafer grinding miller, the top grinding structure of the wafer grinding miller comprises a mounting base and a plurality of grinding assemblies vertically connected to the mounting base in a sliding mode, internal pressure assemblies are mounted in the grinding assemblies, and the internal pressure assemblies are used for applying pressure to a grinding disc. And the pressure intensity P borne by each point of the millstone is reduced along with the increase of the distance r between the millstone and the central point. The wafer grinding machine comprises a supporting structure, a top grinding structure and a bottom driving structure. The grinding device has the effect of improving the grinding effect.

Description

Technical Field

[0001] The present application relates to a wafer grinder, and in particular to a top grinding structure of a wafer grinder and the wafer grinder. Background Art

[0002] In the field of semiconductor manufacturing, the processing accuracy of wafers has a crucial impact on the performance and yield of chips. Wafer grinding is a key link in the wafer processing process. Its purpose is to remove excess material on the wafer surface through the relative movement between the grinding disc and the wafer to achieve the predetermined thickness and flatness requirements.

[0003] Traditional wafer grinding equipment usually adopts a rotating grinding disc structure. In this structure, the grinding disc is driven by a motor to rotate at high speed around its central axis, and the wafer is fixed on the carrier and maintains a certain pressure contact with the grinding disc. During the grinding process, the relative movement between the grinding disc and the wafer produces a grinding effect, so that the material on the wafer surface is gradually removed.

[0004] However, during the rotation of the grinding disc, the linear speed of the edge is much greater than that of the center. According to the principles of physics, the greater the linear speed, the longer the distance the object travels in the same time, and the stronger the grinding effect on the wafer surface. Therefore, during the grinding process, the grinding effect of the edge area of ​​the grinding disc on the wafer is significantly stronger than that of the center area, which leads to uneven grinding of the wafer. Summary of the invention

[0005] In order to improve the uniformity of wafer grinding, the purpose of the present application is to provide a top grinding structure of a wafer grinder and a wafer grinder.

[0006] In the first aspect, the top grinding structure of a wafer grinder provided in the present application adopts the following technical solution:

[0007] A top grinding structure of a wafer grinder comprises a mounting seat, a plurality of grinding assemblies vertically slidably connected to the mounting seat, the mounting seat drives the grinding assembly to move vertically through a first cylinder, the grinding assembly comprises a slider, a rotating shaft rotatably connected to the slider, a driving motor driving the rotating shaft to rotate, and a disc seat connected to the lower end of the rotating shaft, and a grinding disc is fixedly connected to the bottom of the disc seat;

[0008] An internal pressure assembly is installed in the grinding assembly, and the internal pressure assembly is used to apply pressure to the grinding disc, so that the pressure P on each point of the grinding disc decreases as the distance r from the center point increases.

[0009] Through the above technical scheme, the internal pressure component reduces the pressure P exerted on each point of the grinding disc as the distance r from the center point increases, thereby reducing the grinding intensity of the wafer in the edge area of ​​the grinding disc and increasing the grinding intensity of the wafer in the center area of ​​the grinding disc, effectively compensating for the uneven grinding amount caused by the difference in linear speed at different positions of the grinding disc during the grinding process, making the grinding effect of the grinding disc on the wafer more uniform in the entire working area, and significantly improving the flatness and smoothness of the wafer surface.

[0010] Furthermore, the internal pressure assembly is used to apply pressure to the grinding disc so that the pressure P at each point of the grinding disc satisfies the following conditions:

[0011]

[0012] Where: F is the total pressure applied by the internal pressure component to the grinding disc;

[0013] R is the maximum diameter of the grinding disc;

[0014] r is the distance from the center of the grinding disc.

[0015] The above technical solution can further compensate for the uneven grinding amount caused by the difference in linear speed at different positions of the grinding wheel during the grinding process.

[0016] Furthermore, the internal pressure component includes a central cylinder and a plurality of distribution cylinders, the central cylinder is coaxially arranged with the grinding disc, and the distribution cylinders are evenly distributed circumferentially with the center of the grinding disc as the center; the internal pressure component also includes a connecting disc, the grinding disc is bonded to the connecting disc, the movable ends of the central cylinder and the distribution cylinders are fixedly connected to the connecting disc, and the distribution cylinders are arranged in multiple groups, and each group of distribution cylinders has multiple distribution cylinders.

[0017] Through the above technical solution, multiple groups of distributed cylinders are evenly distributed circumferentially with the center of the grinding disc as the center, and connected to different annular force-bearing areas of the connecting disc, and the number of distributed cylinders in each group is specifically set according to the inner and outer diameters of the annular force-bearing area. This layout method can more accurately adjust the force conditions of different areas of the grinding disc, further optimize the pressure distribution curve, ensure that a stable and uniform grinding effect can be maintained under various working conditions, adapt to the grinding needs of wafers of different sizes and materials, and enhance the versatility and adaptability of the wafer grinder.

[0018] Furthermore, the connecting disk includes a force-bearing area and a connection area, the force-bearing area includes a central force-bearing area located at the center of the connecting disk and a plurality of annular force-bearing areas coaxially arranged with the central force-bearing area, the connection area is between adjacent annular force-bearing areas, the connecting disk is provided with an annular deformation groove at the junction of the force-bearing area and the connection area, the annular deformation groove is coaxially arranged with the connecting disk, the connecting disk is provided with a plurality of radial deformation grooves in the connection area, the radial deformation grooves extend radially along the connecting disk, the two ends of the radial deformation grooves are respectively connected to an annular deformation groove, the movable end of the central cylinder is connected to the central force-bearing area of ​​the connecting disk, the distribution cylinder is connected to the annular force-bearing area of ​​the connecting disk, and a group of distribution cylinders corresponds to one annular force-bearing area.

[0019] Through the above technical solution, the deformation capacity of the connecting plate is improved by the deformation groove, which helps the connecting plate to bend appropriately due to different strengths, thereby applying a more appropriate force to the grinding plate and reducing the impact between different cylinders.

[0020] Furthermore, the number of distributed cylinders in each group meets the following requirements:

[0021]

[0022] in: is the number of cylinders in the innermost group of distributed cylinders;

[0023] The number of cylinders close to the second group of distributed cylinders starting from the center of the connecting plate;

[0024] The first The number of cylinders in the group distribution cylinder;

[0025] is the outer diameter of the innermost annular stress-bearing area;

[0026] is the inner diameter of the innermost annular stress-bearing area;

[0027] It is the outer diameter of the second annular force-bearing area from the center of the connecting plate;

[0028] It is the inner diameter of the second annular force-bearing area from the center of the connecting disk;

[0029] The first The outer diameter of the annular force-bearing area;

[0030] The first The inner diameter of the annular force-bearing area.

[0031] Furthermore, the central cylinder includes a cylinder body, a lower end cover fixedly connected to the cylinder body, a piston ring slidably connected to the cylinder body, and a support plate fixedly connected to the piston ring, the cylinder body is provided with an annular cavity for accommodating the piston ring, the edge of the piston ring is provided with an annular edge, the lower end cover is annular and the inner ring is provided with a resistance part, the resistance part extends into the cavity for abutting against the edge to limit the stroke of the piston ring; the disc seat is provided with a center hole, the cylinder body is placed in the center hole and is fixedly connected to the disc seat.

[0032] Furthermore, the cylinder body is provided with a first air duct, one end of which is connected to the top of the annular cavity, and the other end passes through the cylinder body upward and is connected to the center hole. The rotating shaft is hollow and the lower end is connected to the center hole. The upper end of the rotating shaft is connected to the air pipe through a rotating joint.

[0033] Furthermore, the disc seat is provided with a distribution hole for installing a distribution cylinder, and the distribution cylinder includes a guide sleeve arranged in the distribution hole and fixedly connected to the disc seat, a piston plate slidably connected to the distribution hole, and a guide rod fixedly connected to the piston plate, the side wall of the piston plate is in contact with the inner wall of the distribution hole, and the piston plate divides the distribution hole into two independent spaces, one end of the guide rod is fixedly connected to the piston plate, and the other end is fixedly connected to the connecting disc.

[0034] Furthermore, the disc seat is provided with a second air passage, and the second air passage is communicated with the distribution hole.

[0035] In the second aspect, the present application provides a wafer grinding machine adopting the following technical solution:

[0036] A wafer grinding machine, comprising:

[0037] A supporting structure, used for supporting the jig and driving the jig to rotate;

[0038] A top grinding structure of a wafer grinder as described above, located above the support structure, for grinding the wafer;

[0039] The bottom driving structure is used to drive the supporting structure to rotate.

[0040] In summary, the present application includes at least one of the following beneficial technical effects:

[0041] 1. The unique design of the internal pressure component makes the pressure P (r) at each point of the grinding disc decrease as the distance r from the center point increases. This pressure distribution pattern can effectively compensate for the uneven grinding amount caused by the difference in linear speed at different positions of the grinding disc during the grinding process. In the traditional grinding process, since the linear speed of the edge of the grinding disc is much greater than that of the center position, it often causes over-grinding at the edge and under-grinding at the center. In this technology, by precisely controlling the pressure distribution, the grinding disc can grind the wafer more evenly in the entire working area, significantly improving the flatness and smoothness of the wafer surface;

[0042] 2. Multiple groups of distributed cylinders are evenly distributed circumferentially around the center of the grinding disc, and are connected to different annular force-bearing areas of the connecting disc, and the number of distributed cylinders in each group is specifically set according to the inner and outer diameters of the annular force-bearing areas. This layout can more accurately adjust the force conditions in different areas of the grinding disc, further optimize the pressure distribution curve, ensure stable and uniform grinding effects under various working conditions, adapt to the grinding needs of wafers of different sizes and materials, and enhance the versatility and adaptability of the wafer grinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present application;

[0044] Figure 2 is an isometric view of an embodiment of the present application for illustrating a grinding assembly;

[0045] Figure 3 is a cross-sectional view of an embodiment of the present application for showing the internal structure of a grinding assembly;

[0046] Figure 4 This is a schematic diagram of the structure of the embodiment of the present application for showing the distribution of the central cylinder and the distribution cylinders;

[0047] Figure 5 yes Figure 3 A partial enlarged schematic diagram of part A;

[0048] Figure 6 yes Figure 3 A partial enlarged schematic diagram of part B;

[0049] In the figure, 100, support structure; 200, top grinding structure; 210, mounting seat; 220, grinding assembly; 221, slider; 222, rotating shaft; 223, driving motor; 224, disc seat; 225, grinding disc; 226, first cylinder; 230, internal pressure assembly; 231, central cylinder; 2311, cylinder body; 2312, lower end cover; 2313, piston ring; 2314, support disc ; 2315, abutment portion; 2316, edge; 232, distribution cylinder; 2321, guide sleeve; 2322, piston plate; 2323, guide rod; 233, connecting plate; 235, center force area; 236, annular force area; 237, connecting area; 238, annular deformation groove; 239, radial deformation groove; 300, bottom drive structure; 401, first air duct; 402, second air duct. DETAILED DESCRIPTION

[0050] The following is combined with Figure 1 -Attached Figure 6 , further details of this application are given.

[0051] This embodiment discloses a wafer grinding machine, referring to Figure 1 ,include:

[0052] The supporting structure 100 is mainly used to support the fixture, which is used to install and fix the wafer;

[0053] A top grinding structure 200 , located above the support structure 100 , is used to grind the wafer;

[0054] The bottom driving structure 300 provides rotational power for the support structure 100, ensuring that the support structure 100 and the fixture can rotate stably according to the set speed and direction, and cooperates with the top grinding structure 200 to complete the grinding process of the wafer.

[0055] The jig is driven to rotate by the bottom driving structure 300 , so that the wafer placed on the jig can move in a circular motion, so that the top grinding structure 200 can perform a comprehensive grinding operation on it.

[0056] Reference Figure 1 The top grinding structure 200 includes a mounting seat 210 and a plurality of grinding assemblies 220 vertically slidably connected to the mounting seat 210. The mounting seat 210 is rotatably connected to the frame. The mounting seat 210 is equipped with a plurality of first cylinders 226, and the first cylinders 226 are used to drive the grinding assemblies 220 to move vertically.

[0057] Reference Figure 1 and Figure 2The grinding assembly 220 includes a slider 221, a rotating shaft 222 rotatably connected to the slider 221, a driving motor 223 driving the rotating shaft 222 to rotate, and a disc seat 224 connected to the lower end of the rotating shaft 222. A grinding disc 225 is fixedly connected to the bottom of the disc seat 224. The slider 221 is mounted on the mounting seat 210 through a slide rail, and the movable end of the first cylinder 226 is fixedly connected to the slider 221. The slider 221 is driven up and down by the driving of the first cylinder 226. A grinding disc 225 is mounted at the lower end of the disc seat 224. The first cylinder 226 works to drive the slider 221 to move downward, so that the grinding disc 225 abuts against the wafer, and then the driving motor 223 drives the disc seat 224 to rotate through the rotating shaft 222. The rotation of the disc seat 224 drives the grinding disc 225 to rotate, thereby grinding the wafer.

[0058] During the rotation of the grinding disc 225, the linear speed of the edge portion is much greater than that of the central portion, and the grinding effect on the wafer surface is stronger. Therefore, during the grinding process, the grinding effect of the edge area of ​​the grinding disc 225 on the wafer is significantly stronger than that of the central area, which leads to uneven grinding of the wafer.

[0059] Reference Figure 3 In order to solve the above technical problems, an internal pressure assembly 230 is installed in the grinding assembly 220. The internal pressure assembly 230 is used to apply pressure to the grinding disc 225, so that the pressure P (r) at each point of the grinding disc 225 decreases as the distance r from the center point increases. More specifically, the internal pressure assembly 230 is used to apply pressure to the grinding disc 225, so that the pressure P (r) at each point of the grinding disc 225 satisfies the following conditions:

[0060]

[0061] Wherein: F is the total pressure applied to the grinding disc 225 by the internal pressure assembly 230;

[0062] R is the maximum diameter of the grinding disc 225;

[0063] r is the distance from the center point of the grinding disc 225.

[0064] Reference Figure 3 and Figure 4 In order to achieve the above conditions, the internal pressure assembly 230 includes a central cylinder 231 and a plurality of distributed cylinders 232. The central cylinder 231 is installed at the center of the disc seat 224 and is coaxially arranged with the grinding disc 225. The distributed cylinders 232 are evenly distributed in the circumferential direction with the center of the grinding disc 225 as the center. There are multiple groups of distributed cylinders 232, and the distributed cylinders 232 distributed on the same concentric circle are a group. Each group of distributed cylinders 232 has a plurality of distributed cylinders 232 and is evenly distributed with the center of the disc seat 224.

[0065] The internal pressure assembly 230 further includes a connecting plate 233, the grinding plate 225 is bonded to the lower end of the connecting plate 233, and the movable ends of the central cylinder 231 and the distribution cylinder 232 are fixedly connected to the connecting plate 233. The connecting plate 233 includes a force-bearing area and a connecting area 237.

[0066] Reference Figure 4 The force-bearing area includes a central force-bearing area 235 located at the center of the connecting disk 233 and a plurality of annular force-bearing areas 236 coaxially arranged with the central force-bearing area 235. An annular connecting area 237 is arranged between adjacent annular force-bearing areas 236. The connecting disk 233 is provided with an annular deformation groove 238 at the junction of the force-bearing area and the connecting area 237, and the annular deformation groove 238 is coaxially arranged with the connecting disk 233. The connecting disk 233 is provided with a plurality of radial deformation grooves 239 located in the connecting area 237, and the radial deformation grooves 239 extend along the radial direction of the connecting disk 233, and the two ends of the radial deformation grooves 239 are respectively connected to an annular deformation groove 238. The movable end of the central cylinder 231 is connected to the central force-bearing area of ​​the connecting disk 233, and the distribution cylinder 232 is connected to the annular force-bearing area 236 of the connecting disk 233, and a group of distribution cylinders 232 corresponds to one annular force-bearing area 236.

[0067] In order to make the pressure P (r) at each point of the grinding disc 225 meet the above conditions, the pressure applied by each distribution cylinder 232 is the same, and the number of each group of distribution cylinders 232 meets the following requirements:

[0068]

[0069] in: is the number of cylinders of the innermost group of distributed cylinders 232;

[0070] is the number of cylinders close to the second group of distribution cylinders 232 starting from the center of the connection plate 233;

[0071] The first The number of cylinders in the group distribution cylinder 232;

[0072] is the outer diameter of the innermost annular force-bearing area 236;

[0073] is the inner diameter of the innermost annular force-bearing area 236;

[0074] The outer diameter of the second annular force-bearing area 236 from the center of the connecting plate 233;

[0075] The inner diameter of the second annular force-bearing area 236 from the center of the connecting plate 233;

[0076] The first The outer diameter of the annular force-bearing area 236;

[0077] The first The inner diameter of the annular force-bearing area 236.

[0078] Reference Figure 4 , taking 8-inch wafers as an example, four wafers are ground simultaneously. F uses 125.6Kg, and the R of the grinding disc is 30cm. There are two sets of distribution cylinders 232 set from inside to outside. 40 , , , ;but The first group is set with 7 pieces and the second group is set with 11 pieces.

[0079] Reference Figure 5 The disc seat 224 is provided with a central hole for installing the central cylinder 231.

[0080] The central cylinder 231 includes a cylinder body 2311, a lower end cover 2312, a piston ring 2313 and a support plate 2314. The cylinder body 2311 is placed in the central hole and fixedly connected to the plate seat 224. The lower end cover 2312 is fixedly connected to the cylinder body 2311. The cylinder body 2311 is provided with an annular ring-shaped cavity for accommodating the piston ring 2313, and the piston ring 2313 is slidably connected in the cylinder body 2311. The edge of the piston ring 2313 is integrally formed with an annular edge 2316. The lower end cover 2312 is annular and the inner ring is provided with an annular abutment 2315, which extends into the cavity for abutting against the edge 2316 to limit the stroke of the piston ring 2313.

[0081] The cylinder 2311 is provided with a first air passage 401, one end of which is connected to the top of the annular cavity, and the other end of which passes through the cylinder 2311 upwards and is connected to the center hole. The rotating shaft 222 is hollow, and the lower end is connected to the center hole. The upper end of the rotating shaft 222 is connected to the air pipe through a rotating joint.

[0082] Reference Figure 6 The disc seat 224 is provided with distribution holes for installing the distribution cylinder 232 .

[0083] The distribution cylinder 232 includes a guide sleeve 2321 disposed in the distribution hole and fixedly connected to the disc seat 224, a piston sheet 2322 slidably connected to the distribution hole, and a guide rod 2323 fixedly connected to the piston sheet 2322. The side wall of the piston sheet 2322 fits the inner wall of the distribution hole, and the piston sheet 2322 divides the distribution hole into two independent spaces. One end of the guide rod 2323 is fixedly connected to the piston sheet 2322, and the other end is fixedly connected to the connecting disc 233; the disc seat 224 is provided with a second air channel 402, and the second air channel 402 is connected to the distribution hole.

[0084] The implementation principle of the embodiment of the present application is as follows: the unique design of the internal pressure component 230 makes the pressure P (r) at each point of the grinding disc 225 decrease as the distance r from the center point increases. This pressure distribution pattern can effectively compensate for the uneven grinding amount of the grinding disc 225 caused by the difference in linear speed at different positions during the grinding process. In the traditional grinding process, since the linear speed of the edge of the grinding disc 225 is much greater than that of the center position, it often causes excessive grinding at the edge and insufficient grinding at the center. In this technology, by precisely controlling the pressure distribution, the grinding disc 225 can grind the wafer more evenly in the entire working area, significantly improving the flatness and smoothness of the wafer surface.

Claims

1. A top grinding structure of a wafer grinder, characterized in that: The invention comprises a mounting seat (210), and a plurality of grinding assemblies (220) vertically slidably connected to the mounting seat (210); the mounting seat (210) drives the grinding assemblies (220) to move vertically via a first cylinder (226); the grinding assemblies (220) comprise a slider (221), a rotating shaft (222) rotatably connected to the slider (221), a driving motor (223) driving the rotating shaft (222) to rotate, and a disc seat (224) connected to the lower end of the rotating shaft (222); a grinding disc (225) is fixedly connected to the bottom of the disc seat (224); An internal pressure component (230) is installed in the grinding component (220), and the internal pressure component (230) is used to apply pressure to the grinding disc (225), so that the pressure P (r) exerted on each point of the grinding disc (225) decreases as the distance r from the center point increases.

2. The top grinding structure of a wafer grinder according to claim 1, characterized in that: The internal pressure component (230) is used to apply pressure to the grinding disc (225) so that the pressure P (r) applied to each point of the grinding disc (225) satisfies the following conditions: ； Wherein: F is the total pressure applied by the internal pressure assembly (230) to the grinding disc (225); R is the maximum diameter of the grinding disc (225); r is the distance from the center point of the grinding disc (225).

3. The top grinding structure of a wafer grinder according to claim 2, characterized in that: The internal pressure component (230) comprises a central cylinder (231) and a plurality of distribution cylinders (232); the central cylinder (231) is coaxially arranged with the grinding disc (225); the distribution cylinders (232) are evenly distributed in the circumferential direction with the center of the grinding disc (225) as the center; the internal pressure component (230) further comprises a connecting disc (233); the grinding disc (225) is bonded to the connecting disc (233); the movable ends of the central cylinder (231) and the distribution cylinders (232) are fixedly connected to the connecting disc (233); the distribution cylinders (232) are arranged in a plurality of groups, and each group of distribution cylinders (232) has a plurality of distribution cylinders (232).

4. The top grinding structure of a wafer grinder according to claim 3, characterized in that: The connecting disk (233) comprises a force-bearing area and a connecting area (237), wherein the force-bearing area comprises a central force-bearing area (235) located at the center of the connecting disk (233) and a plurality of annular force-bearing areas (236) coaxially arranged with the central force-bearing area (235), wherein the connecting area (237) is located between adjacent annular force-bearing areas (236), and the connecting disk (233) is provided with an annular deformation groove (238) at the junction of the force-bearing area and the connecting area (237), wherein the annular deformation groove (238) is coaxially arranged with the connecting disk (233), and the connecting disk (233) is provided with a plurality of radial deformation grooves (239) in the connection area (237), the radial deformation grooves (239) extending along the radial direction of the connection disk (233), the two ends of the radial deformation grooves (239) are respectively connected to an annular deformation groove (238), the movable end of the central cylinder (231) is connected to the center force area (235) of the connection disk (233), the distribution cylinder (232) is connected to the annular force area (236) of the connection disk (233), and a group of distribution cylinders (232) corresponds to one annular force area (236).

5. The top grinding structure of a wafer grinder according to claim 4, characterized in that: The number of each group of distributed cylinders (232) meets the following requirements: ； in: is the number of cylinders of the innermost group of distribution cylinders (232); is the number of cylinders close to the second group of distribution cylinders (232) starting from the center of the connection plate (233); is the number of cylinders close to the xth group of distribution cylinders (232) starting from the center of the connection plate (233); is the outer diameter of the innermost annular force-bearing area (236); is the inner diameter of the innermost annular force-bearing area (236); The outer diameter of the second annular force-bearing area (236) starting from the center of the connecting plate (233); The inner diameter of the second annular force-bearing area (236) starting from the center of the connecting plate (233); is the outer diameter of the xth annular force-bearing area (236) starting from the center of the connecting plate (233); It is the inner diameter of the xth annular force-bearing area (236) starting from the center of the connecting plate (233).

6. The top grinding structure of a wafer grinder according to claim 3, characterized in that: The central cylinder (231) comprises a cylinder body (2311), a lower end cover (2312) fixedly connected to the cylinder body (2311), a piston ring (2313) slidably connected to the cylinder body (2311), and a support plate (2314) fixedly connected to the piston ring (2313); the cylinder body (2311) is provided with an annular cavity for accommodating the piston ring (2313); the edge of the piston ring (2313) is provided with an annular edge (2316); the lower end cover (2312) is annular and has an inner ring provided with a contact portion (2315); the contact portion (2315) extends into the cavity for contacting with the edge (2316) to limit the stroke of the piston ring (2313); the disc seat (224) is provided with a central hole; the cylinder body (2311) is placed in the central hole and is fixedly connected to the disc seat (224).

7. The top grinding structure of a wafer grinder according to claim 6, characterized in that: The cylinder body (2311) is provided with a first air channel (401), one end of the first air channel (401) is connected to the top of the annular cavity, and the other end of the first air channel (401) passes through the cylinder body (2311) upwards and is connected to the center hole. The rotating shaft (222) is hollow and the lower end is connected to the center hole. The upper end of the rotating shaft (222) is connected to the air pipe via a rotating joint.

8. The top grinding structure of a wafer grinder according to claim 7, characterized in that: The disc seat (224) is provided with a distribution hole for installing a distribution cylinder (232); the distribution cylinder (232) comprises a guide sleeve (2321) arranged in the distribution hole and fixedly connected to the disc seat (224), a piston plate (2322) slidably connected to the distribution hole, and a guide rod (2323) fixedly connected to the piston plate (2322); a side wall of the piston plate (2322) is fitted with an inner wall of the distribution hole, and the piston plate (2322) divides the distribution hole into two independent spaces; one end of the guide rod (2323) is fixedly connected to the piston plate (2322), and the other end is fixedly connected to the connecting disc (233).

9. The top grinding structure of a wafer grinder according to claim 8, characterized in that: The disc seat (224) is provided with a second air channel (402), and the second air channel (402) is connected to the distribution hole.

10. A wafer grinding machine, characterized in that: include: A support structure (100), used for supporting the jig and driving the jig to rotate; A top grinding structure of a wafer grinder as claimed in any one of claims 1 to 8, located above the support structure (100), and used for grinding wafers; The bottom driving structure (300) is used to drive the supporting structure (100) to rotate.

Images