Automatic silicon wafer super-polishing equipment

Abstract

This invention relates to the field of silicon wafer processing technology, specifically to an automatic ultra-precision grinding equipment for silicon wafers. The automatic ultra-precision grinding equipment of this invention features multiple silicon wafer fixing devices on the worktable. A spatial displacement device drives the precision grinding device to adapt to each silicon wafer fixing device, thus greatly improving processing efficiency. Each silicon wafer fixing device utilizes a plane adjustment mechanism to adjust the position of the silicon wafer on the clamping fixture relative to the precision grinding device. A levelness adjustment mechanism further adjusts the levelness of the grinding surface formed by the edges of the stacked silicon wafers on the clamping fixture relative to the grinding plane of the precision grinding device, ensuring the flatness of the silicon wafer edges and preventing inconsistent sizes among silicon wafers from the same batch. Finally, an angle adjustment mechanism adjusts the length direction of the multiple silicon wafers on the clamping fixture relative to the grinding direction of the precision grinding device, ensuring grinding quality.

Description

Technical Field

[0001] This invention relates to the field of silicon wafer processing technology, and more specifically to an automatic ultra-precision grinding equipment for silicon wafers. Background Technology

[0002] During the production process, silicon wafers often become defective due to impacts and other reasons. Specifically, chipping and microcracks may occur on the side of the silicon wafer. Since silicon wafers are very thin, generally only 100 to 170 micrometers thick, most of the industry currently repairs them by manual polishing. However, this method is extremely dependent on the operator's skill level, and manual polishing is slow, the polishing quality cannot be controlled, and may even damage the defective products to the point of scrap.

[0003] In some similar fields, such as the patent with publication number CN111482865A, a wafer grinding device is disclosed. Its vacuum chuck shaft mechanism's first shaft carries and drives the wafer to rotate. The clamping mechanism's clamping element abuts against the wafer to press it against the first shaft. The positioning mechanism's positioning element can perform secondary positioning of the wafer before the clamping mechanism performs the clamping operation. The grinding machine of the grinding mechanism can move axially and radially along the first shaft. Driven by the first shaft, the wafer rotates, and the grinding machine moves radially along the first shaft to contact the edge of the wafer, thus achieving edge grinding. Therefore, this grinding device is suitable for edge grinding of circular silicon wafers, but it can only process one wafer at a time. Regarding the processing of square wafers, the patent with publication number CN116394102A discloses a silicon wafer edge grinding machine. This edge grinding machine optimizes the driving module of the grinding device to make the equipment compatible with edge grinding of both circular and square silicon wafers. However, in this patent, the vacuum chuck shaft mechanism is fixed in position relative to the frame, and this mechanism can only hold a single wafer, resulting in low processing efficiency and an inability to grind multiple wafers. Therefore, processing plants typically replace the vacuum chuck shaft mechanism with a grinding jig, such as the single-crystal silicon wafer grinding jig disclosed in patent publication number CN218137314U. These jigs can simultaneously hold multiple square wafers, which is advantageous. However, these jigs are generally fixed relative to the frame and cannot be adjusted spatially, especially regarding the adjustment between the grinding sides of multiple square wafers and the processing plane of the grinding wheel. This places higher demands on the installation accuracy of the grinding jig itself and the precision required to hold the wafers. Therefore, when this type of fixture holds multiple square wafers, the grinding surface formed by the edges of these wafers may have a slight tilt or be tilted relative to the grinding wheel's processing plane. If the grinding wheel directly grinds these wafers, it may result in a certain height difference between the wafers being ground in the same batch and the grinding wheel's processing plane, meaning the wafer dimensions are inconsistent, directly affecting the quality of subsequent wafer processing. Simultaneously, during processing, since the grinding direction of the grinding wheel is generally parallel to the length direction of the wafer's edges, this effectively regulates the direction of force on the wafer, preventing lateral force on the wafers and avoiding damage to the surrounding wafers in the stack of multiple wafers held together, thus ensuring wafer quality. Summary of the Invention

[0004] In order to overcome one of the shortcomings of the prior art, the purpose of this invention is to provide an automatic ultra-precision grinding equipment for silicon wafers. This automatic ultra-precision grinding equipment can accurately adjust the grinding angle and grinding level of the silicon wafers to ensure the grinding quality.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] An automated ultra-precision grinding equipment for silicon wafers, comprising:

[0007] A frame on which a worktable is mounted;

[0008] A plurality of silicon wafer fixing devices are provided, all of which are mounted on the worktable. Each silicon wafer fixing device includes a plane adjustment mechanism and a level adjustment mechanism. The bottom of the plane adjustment mechanism is slidably mounted on the worktable and can be locked relative to the worktable. The level adjustment mechanism is mounted on the top of the plane adjustment mechanism, and an angle adjustment mechanism is provided on the top of the angle adjustment mechanism. A clamping fixture for fixing the silicon wafer is provided on the top of the angle adjustment mechanism.

[0009] A spatial displacement device, which is mounted on the frame;

[0010] A fine grinding device is installed on the adjustment end of the spatial displacement device, and the fine grinding device is capable of grinding all the silicon wafers on the clamping fixture.

[0011] In some possible embodiments, the leveling adjustment mechanism includes a fixed housing and four lifting screws, which are rotatably mounted on the four corners of the fixed housing. The angle adjustment mechanism is mounted on the top of the fixed housing. The lower ends of the four lifting screws abut against the top of the plane adjustment mechanism. The top of the plane adjustment mechanism is provided with several sliding guide posts, and the fixed housing is provided with several sliding holes that cooperate with the sliding guide posts. The fixed housing can slide on the sliding guide posts but cannot slide out from the top of the sliding guide posts. Two sets of adjusting members are installed on the fixed housing. Each set of adjusting members can cooperate with two of the lifting screws and can independently adjust the extension amount of the lower end of any one of the lifting screws.

[0012] In some possible embodiments, each of the adjusting components includes an operating shaft and two worm gears movably mounted on the operating shaft. Both ends of the operating shaft are rotatably mounted on two opposing inner sidewalls of the fixed housing. One end of the operating shaft extends movably out of the fixed housing, and the operating shaft is slidable on the fixed housing along its axial direction. The end of the operating shaft outside the fixed housing forms an operating end. Each of the two worm gears meshes individually with two lifting screws on the same side. Two sets of friction plates are provided on the area between the two worm gears on the operating shaft. When the operating shaft slides along either end of the axis of the two worm gears, each set of friction plates can only abut against the side surface of the corresponding end of the worm gear.

[0013] In some possible embodiments, the friction plate has a plurality of friction strips protruding outward on the side near the worm gear, and the worm gear has a plurality of grooves that mate with the friction strips on the side near the friction plate.

[0014] In some possible embodiments, a fixing sleeve is fitted on both ends of the operating shaft. The opposite ends of the two fixing sleeves are rotatably mounted on the inner sidewall of the fixed housing. The two worm gears are coaxially mounted on the fixing sleeves. The two worm gears can rotate with the corresponding fixing sleeves. The opposite ends of the two fixing sleeves do not protrude from the opposite side of the corresponding worm gear.

[0015] In some possible embodiments, the angle adjustment mechanism includes a base and a shaft column disposed on the base, the base being mounted on the top of the fixed housing; the base has an mounting annular groove on the outer periphery of the shaft column, an mounting spacer is disposed in the mounting annular groove, a bearing is fitted on the mounting spacer, a rotating ring is fitted on the outer ring of the bearing, a mounting seat is disposed on the rotating ring, and the clamping fixture is detachably mounted on the mounting seat; a push arm extends outward from the outer wall of the rotating ring, a mounting block extends outward from the base, a limiting groove is formed on the mounting block, one end of the push arm is disposed in the limiting groove, and fine adjustment rods are screwed through both sides of the mounting block located in the limiting groove, the opposite ends of the two fine adjustment rods being able to abut against the side wall of the outward end of the push arm.

[0016] In some possible embodiments, the planar adjustment mechanism includes a sliding seat, a longitudinal sliding seat slidably disposed on the sliding seat, and a transverse sliding seat slidably disposed on the longitudinal sliding seat. The sliding seat is slidably mounted on a slide rail of the worktable. A locking knob is provided on the sliding seat, which can lock the sliding seat and the slide rail relative to each other. The levelness adjustment mechanism is mounted on the transverse sliding seat. A first fixing block is provided on one side of the longitudinal sliding seat. A first top block is provided on the sliding seat. A first rotating rod is screwed through the first top block, and one end of the first rotating rod is rotatably connected to the first fixing block. A second top block is provided on the longitudinal sliding seat, and a second fixing block is provided on the transverse sliding seat. A second rotating rod is screwed through the second top block, and one end of the second rotating rod is rotatably connected to the second fixing block.

[0017] In some possible embodiments, the spatial displacement device includes a sliding rail mounted on a frame, a sliding seat slidably mounted on the sliding rail, and a lifting rail mounted on the sliding seat. A sliding motor is provided on the frame, and the output end of the sliding motor is rotatably connected to a lead screw nut on the sliding seat via a horizontal lead screw. A lifting seat is slidably mounted on the lifting rail, and the fine grinding device is mounted on the lifting seat. A vertical lead screw is provided on the sliding seat, and the vertical lead screw is connected to the lifting seat via a lead screw nut. A lifting motor connected to one end of the vertical lead screw is provided on the sliding seat.

[0018] In some possible embodiments, the fine grinding device includes a drive motor and a grinding wheel. The drive motor is mounted on the lifting seat, and the lifting seat is provided with a mounting plate. A rotating shaft is rotatably mounted on the mounting plate. The grinding wheel is detachably mounted on one end of the rotating shaft, and the other end of the rotating shaft meshes with the output end of the drive motor through a gear.

[0019] In some possible embodiments, the workbench is equipped with a loading and unloading robot.

[0020] Compared to existing technologies, the advantages of this invention are as follows: The automatic ultra-precision grinding equipment for silicon wafers of this invention features multiple silicon wafer fixing devices on the worktable. A spatial displacement device drives the precision grinding device to adapt to each silicon wafer fixing device, thus greatly improving the processing effect. Each silicon wafer fixing device utilizes a plane adjustment mechanism to adjust the position of the silicon wafer on the clamping fixture relative to the precision grinding device. A levelness adjustment mechanism further adjusts the levelness of the grinding surface formed by the edges of the stacked silicon wafers on the clamping fixture relative to the grinding plane of the precision grinding device, ensuring the flatness of the silicon wafer edges and preventing inconsistent sizes in the same batch of silicon wafers. Finally, an angle adjustment mechanism adjusts the length direction of the multiple silicon wafers on the clamping fixture relative to the grinding direction of the precision grinding device, ensuring the grinding quality. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a front view of the automated ultra-fine grinding equipment for silicon wafers according to an embodiment of the present invention;

[0023] Figure 2 This is a top view of the automated ultra-fine grinding equipment for silicon wafers according to an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the silicon wafer fixing device in an embodiment of the present invention. Figure 1 ;

[0025] Figure 4 This is a schematic diagram of the silicon wafer fixing device in an embodiment of the present invention. Figure 2 ;

[0026] Figure 5 This is a cross-sectional view of the silicon wafer fixing device in an embodiment of the present invention;

[0027] Figure 6 yes Figure 5 A magnified view of a section at point A in the middle;

[0028] Figure 7 This is a schematic diagram of the fine grinding device in an embodiment of the present invention.

[0029] Explanation of icon numbers:

[0030] Frame 100, worktable 110, slide rail 120;

[0031] The components include: silicon wafer fixing device 200, plane adjustment mechanism 210, sliding guide post 211, sliding seat 212, longitudinal slide seat 213, transverse slide seat 214, first fixing block 215, first top block 216, first rotating rod 217, second top block 218, second fixing block 219, second rotating rod 21a, locking knob 21b, levelness adjustment mechanism 220, fixed housing 221, lifting screw 222, sliding hole 223, operating shaft 224, worm gear 225, operating end 226, friction plate 227, friction strip 228, groove 229, fixing sleeve 22a, angle adjustment mechanism 230, base 231, shaft post 232, mounting ring groove 233, mounting spacer 234, bearing 235, rotating ring 236, mounting seat 237, push arm 238, mounting block 239, limiting groove 23a, fine adjustment rod 23b, and clamping fixture 240.

[0032] Spatial displacement device 300, sliding rail 310, sliding seat 320, lifting rail 330, sliding motor 340, horizontal lead screw 350, lifting seat 360, vertical lead screw 370, lifting motor 380, mounting plate 390;

[0033] Fine grinding device 400, drive motor 410, grinding wheel 420, rotating shaft 430, gear 440. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] See Figures 1 to 7This application provides an automatic ultra-fine grinding equipment for silicon wafers, comprising a frame 100, a plurality of silicon wafer fixing devices 200, a spatial displacement device 300, and a fine grinding device 400; a worktable 110 is provided on the frame 100; all silicon wafer fixing devices 200 are mounted on the worktable 110, and each silicon wafer fixing device 200 includes a plane adjustment mechanism 210 and a level adjustment mechanism 220, the bottom of the plane adjustment mechanism 210 being slidably mounted on the worktable 110, and the plane adjustment mechanism 210 being able to... It can be locked relative to the worktable 110; the level adjustment mechanism 220 is installed on the top of the plane adjustment mechanism 210, the top of the level adjustment mechanism 220 is provided with an angle adjustment mechanism 230, and the top of the angle adjustment mechanism 230 is provided with a clamping fixture 240 for fixing silicon wafers; the spatial displacement device 300 is installed on the frame 100; the fine grinding device 400 is installed on the adjustment end of the spatial displacement device 300, and the fine grinding device 400 can grind all the silicon wafers on the clamping fixture 240.

[0036] The spatial displacement device 300 can be understood as a conventional multi-axis robot or a conventional spatial cross-slide structure. Its main purpose is to adjust the spatial position of the fine grinding device 400 to adapt to the silicon wafer fixing device 200 in different positions, thus greatly improving the breadth of the processing operation surface. The structure of the fine grinding device 400 is relatively simple and can be a conventional grinding equipment, such as the novel peristaltic pump and grinding wheel combination structure for a silicon wafer grinding machine disclosed in patent publication number CN204163963U, which will not be described in detail here.

[0037] It should be noted that the main function of the plane adjustment mechanism 210 is to adjust the projected position of the entire clamping fixture 240 relative to the horizontal plane of the machining end of the precision grinding device 400. This reduces the range of motion of the entire precision grinding device 400 while ensuring that the precision grinding device 400 can grind all the silicon wafers clamped on the clamping fixture 240. For this reason, the plane adjustment mechanism 210 can be a conventional cross slide structure. The main function of the level adjustment mechanism 220 is to adjust the levelness between all the silicon wafers to be processed clamped on the clamping fixture 240 and the machining plane of the worktable 110 or the precision grinding device 400. This avoids the problem of uneven grinding surfaces caused by manual clamping errors, effectively ensuring the grinding accuracy of each silicon wafer. In addition, the main function of the angle adjustment mechanism 230 is to adjust the length direction of the silicon wafer held on the clamping fixture 240 and the grinding direction of the processing end on the fine grinding device 400, so as to avoid the fine grinding device 400 generating excessive lateral force on the silicon wafer during the processing and effectively ensure the processing quality.

[0038] This automatic ultra-precision silicon wafer grinding equipment features multiple silicon wafer fixing devices 200 on the worktable 110. A spatial displacement device 300 drives the precision grinding device 400 to fit each silicon wafer fixing device 200, significantly improving processing efficiency. Each silicon wafer fixing device 200 uses a plane adjustment mechanism 210 to adjust the position of the silicon wafer on the clamping fixture 240 relative to the precision grinding device 400. A levelness adjustment mechanism 220 adjusts the levelness of the surface to be ground, formed by the edges of multiple silicon wafers on the clamping fixture 240, relative to the grinding plane of the precision grinding device 400, ensuring the flatness of the silicon wafer edges and preventing inconsistent sizes among wafers from the same batch. An angle adjustment mechanism 230 adjusts the length direction of the multiple silicon wafers on the clamping fixture 240 relative to the grinding direction of the precision grinding device 400, ensuring grinding quality.

[0039] In some possible embodiments, see Figures 1 to 6 To better achieve position adjustment, the planar adjustment mechanism 210 includes a sliding seat 212, a longitudinal slide 213 slidably mounted on the sliding seat 212, and a transverse slide 214 slidably mounted on the longitudinal slide 213. The sliding seat 212 is slidably mounted on the slide rail 120 of the worktable 110. A locking knob 21b is provided on the sliding seat 212, which can lock the sliding seat 212 and the slide rail 120 respectively. The levelness adjustment mechanism 220 is mounted on the transverse slide 214. A first fixing block 215 is provided on one side of the longitudinal slide 213, a first top block 216 is provided on the slide 212, a first rotating rod 217 is screwed through the first top block 216, and one end of the first rotating rod 217 is rotatably connected to the first fixing block 215; a second top block 218 is provided on the longitudinal slide 213, a second fixing block 219 is provided on the transverse slide 214, a second rotating rod 21a is screwed through the second top block 218, and one end of the second rotating rod 21a is rotatably connected to the second fixing block 219.

[0040] The longitudinal slide 213 and the transverse slide 214 together form a cross slide, which is mainly for the purpose of facilitating precise adjustment of the horizontal position. In this application, the longitudinal slide 213 and the transverse slide 214 have the same structure, and the adjustment method between them is also similar. This simplifies the structural design and facilitates the maintenance or replacement of parts in the later stages.

[0041] In this application, the lateral direction is defined as the direction from which the worker's left and right hands are located, with the side facing the grinding equipment as the reference. The longitudinal direction is the direction from which the worker's left and right hands are located, while the longitudinal direction is the direction from which the worker's left and right hands are located. The slide rail 120 is designed longitudinally in this application, meaning it is parallel to the direction from which the worker's left and right hands are located.

[0042] The first top block 216 is equipped with a nut or a nut-like structure, while the outer wall of the first rotating rod 217 has an external thread that mates with the nut. By engaging the internal thread of the nut with the external thread of the first top block 216, the extension distance of the first rotating rod 217 can be steplessly adjusted, i.e., the distance by which the first fixing block 215 is pushed away from the first top block 216, thus achieving fine-tuning in the lateral direction. The precision of the external thread on the outer wall of the first rotating rod 217 and the internal thread of the nut on the first top block 216 determines the adjustment accuracy in the lateral direction, and therefore will not be elaborated upon here. Similarly, in the longitudinal direction, the second top block 218, the second fixing block 219, and the second rotating rod 21a have the same structural design and working principle, and will not be detailed here.

[0043] See Figures 3 to 5 To achieve high-precision adjustment of the level of the silicon wafer processing surface held on the clamping fixture 240, in one embodiment of this application, the level adjustment mechanism 220 includes a fixed housing 221 and four lifting screws 222. The four lifting screws 222 are rotatably mounted on the four corners of the fixed housing 221. Angle adjustment mechanism 230 is installed on the top of the fixed housing 221. The lower ends of the four lifting screws 222 abut against the top of the plane adjustment mechanism 210. The top of the plane adjustment mechanism 210 is provided with a plurality of sliding guide posts 211. The fixed housing 221 is provided with a plurality of sliding holes 223 that cooperate with the sliding guide posts 211. The fixed housing 221 can slide on the sliding guide posts 211 but cannot slide out from the top of the sliding guide posts 211. Two sets of adjustment components are installed on the fixed housing 221. Each set of adjustment components can cooperate with two lifting screws 222 and can independently adjust the extension amount of the lower end of any one of the lifting screws 222.

[0044] The main function of the sliding guide post 211 is to restrict the spatial position of the fixed housing 221. Simultaneously, utilizing the gap between the sliding guide post 211 and the sliding hole 223, the height of each corner of the top surface of the fixed housing 221 can be finely adjusted under the force of the lifting screw 222, thereby adjusting the levelness of the top surface of the fixed housing 221. In practice, the sliding guide post 211 is installed on the top of the transverse slide block 214, and the lower end of the lifting screw 222 also abuts against the top of the transverse slide block 214. Furthermore, the adjustment range of the lifting screw 222 in cooperation with the adjusting component is very small; therefore, the gap between the sliding guide post 211 and the sliding hole 223 should not be too large. This design can, to a certain extent, ensure the tightness between the sliding guide post 211 and the fixed housing 221, preventing loosening. In some improved embodiments, a precision linear bearing is also provided inside the sliding hole 223, which cooperates with the sliding guide post 211 to a certain extent to ensure the smooth sliding of the fixed housing 221 relative to the sliding guide post 211 and reduce the swaying of the fixed housing 221 relative to the sliding guide post 211, thus playing a limiting role. In addition, a stop structure is provided on the top of the sliding guide post 211 to limit the sliding distance of the fixed housing 221.

[0045] See further Figure 5To facilitate the adjustment of the lifting of each lifting screw 222, in one embodiment of this application, each adjusting component includes an operating shaft 224 and two worm gears 225 movably mounted on the operating shaft 224. Both ends of the operating shaft 224 are rotatably mounted on two opposite inner sidewalls of the fixed housing 221. One end of the operating shaft 224 extends movably out of the fixed housing 221, and the operating shaft 224 can slide along its axial direction on the fixed housing 221. The end of the operating shaft 224 located outside the fixed housing 221 forms an operating end 226. The two worm gears 225 respectively mesh with the two lifting screws 222 on the same side. Two sets of friction plates 227 are provided on the area between the two worm gears 225 on the operating shaft 224. When the operating shaft 224 slides along either end of the axis of the two worm gears 225, each set of friction plates 227 can only abut against the side of the corresponding worm gear 225. In this design, the friction plate 227, after contacting the side of the worm gear 225, can drive the worm gear 225 to rotate through friction, thus resembling a clutch design. It should be noted that in this embodiment, because the external teeth of the worm gear 225 need to mate with the outer shape of the lifting screw 222, an arc-shaped groove is provided on the outer shape of the worm gear 225. Therefore, it will not slip relative to the operating shaft 224 and will be confined to the meshing position with the lifting screw 222. This design ensures that the worm gear 225 will not slide when the operating shaft 224 moves along its axial direction, effectively guaranteeing the engagement between the worm gear 225 and the lifting screw 222. In practice, adjusting the level of the top of the fixed housing 221 only requires adjusting the two lifting screws 222 to achieve a level top surface for the entire fixed housing 221. Therefore, adjusting the level of the fixed housing 221 is relatively simple and convenient in actual adjustment. It should be noted that, since the friction between the fixed housing 221 and the sliding guide post 211 is sufficient to achieve self-locking after adjusting the lifting screw 222 relative to the fixed housing 221, there is no need to worry about the fixed housing 221 springing back on the sliding guide post 211. Furthermore, since the sliding stroke between the fixed housing 221 and the sliding guide post 211 is very short, with a conventional adjustment stroke of only 0.1-3mm, the adjustment in this application is only a fine-tuning. Therefore, the clearance between the sliding guide post 211 and the sliding hole 223 is sufficient to meet the aforementioned motion requirements.

[0046] In the above embodiments, the overall adjustment principle is relatively simple. Each operating shaft 224 can adjust two worm gears 225 on the same side respectively. If there is a certain height difference between one corner of the fixed housing 221 and other corners, it is only necessary to pull the corresponding operating shaft 224. The friction plate 227 abuts against the side of the worm gear 225 corresponding to the lifting screw 222 to be adjusted. This will drive the worm gear 225 to rotate, thereby realizing the lifting of the lifting screw 222 to be adjusted, and finally realizing the adjustment of the corner of the fixed housing 221 to be adjusted. If it is necessary to adjust the height of multiple corners to make the top surface of the fixed housing 221 horizontal, the adjustment principle of the extension of each lifting screw 222 is the same, which will not be described in detail here.

[0047] In some possible embodiments, to facilitate the rotation of the worm gear 225 by the friction plate 227, a plurality of friction strips 228 are provided protruding outward on the side of the friction plate 227 near the worm gear 225, and a plurality of grooves 229 that mate with the friction strips 228 are provided on the side of the worm gear 225 near the friction plate 227. The engagement of the friction strips 228 and the grooves 229 greatly improves the tightness of the fit and the friction, thereby facilitating the adjustment of torque transmission between them.

[0048] Because the worm gear 225 is subjected to lateral force when it rotates, it is not directly aligned with the mating surface of the lifting screw 222. This can lead to unstable mating or discontinuous transmission of driving force during torque transmission. To address this issue, fixed sleeves 22a are fitted onto both ends of the operating shaft 224. The opposite ends of the two fixed sleeves 22a are rotatably mounted on the inner wall of the fixed housing 221. The two worm gears 225 are coaxially mounted on the fixed sleeves 22a, and they can rotate with their respective fixed sleeves 22a. Neither of the opposite ends of the two fixed sleeves 22a protrudes beyond the opposite side of the corresponding worm gear 225. The fixed sleeves 22a effectively restrict the position of the worm gears 225, ensuring proper mating with the lifting screw 222 and guaranteeing torque transmission between them. Simultaneously, the fixed sleeves 22a keep the worm gears 225 pressed firmly against the outer wall of the lifting screw 222, preventing them from wobbling during torque transmission.

[0049] In some possible embodiments, see Figure 5 and Figure 6To adjust the angle between the silicon wafer on the clamping fixture 240 and the grinding direction of the precision grinding device 400, the angle adjustment mechanism 230 includes a base 231 and a shaft 232 mounted on the base 231. The base 231 is mounted on the top of the fixed housing 221. A mounting annular groove 233 is provided on the outer periphery of the shaft 232 on the base 231. A mounting spacer 234 is provided within the mounting annular groove 233. A bearing 235 is fitted onto the mounting spacer 234. A rotating ring 236 is fitted around the outer ring of the bearing 235. The rotating ring 236 is provided with... Mounting base 237, clamping fixture 240 is detachably mounted on mounting base 237; push arm 238 is provided outwardly on the outer wall of rotating ring 236, mounting block 239 is provided outwardly on base 231, mounting block 239 is provided with limiting groove 23a, one end of push arm 238 is set in limiting groove 23a, fine adjustment rods 23b are screwed through the mounting block 239 on both sides of limiting groove 23a, and the opposite ends of the two fine adjustment rods 23b can abut against the side wall of the outward end of push arm 238.

[0050] It should be further explained that the main purpose of the spacer 234 is to provide a stable rotational contact. Through the rotating ring 236, it can, to a certain extent, limit the rotational runout caused by the gap between its inner ring and the outer wall of the shaft column 232 when rotating around its own axis, thus ensuring the rotational stability of the mounting base 237. Furthermore, by utilizing the cooperation between the rotating ring 236 and the bearing 235, the wear of the bearing 235 can be reduced to a certain extent through a double-sliding structure, thereby ensuring the overall rotational precision.

[0051] Furthermore, in the above embodiment, the two fine-tuning rods 23b are used to adjust the clockwise and counterclockwise rotation direction of the rotating ring 236, respectively. Simultaneously, the two fine-tuning rods 23b cooperate to limit the rotational position of the rotating ring 236, achieving locking. At the same time, the two fine-tuning rods 23b are threadedly connected to the mounting block 239, forming a stepless adjustment structure, improving the fine-tuning capability.

[0052] See Figure 1 and Figure 2The main function of the spatial displacement device 300 is to drive the fine grinding device 400 to adapt to the different silicon wafer positions on the silicon wafer fixing device 200. Therefore, the spatial displacement device 300 can adopt a conventional multi-axis robot or other structure, as long as it can achieve spatial position adjustment. In some possible embodiments, in order to maintain stability during the movement of the fine grinding device 400, reduce vibration during the grinding process, and reduce the influence of the deflection of the spatial displacement device 300 itself, the spatial displacement device 300 includes a sliding rail 310 mounted on the frame 100, a sliding seat 320 slidably mounted on the sliding rail 310, and a lifting rail 330 mounted on the sliding seat 320. A sliding motor 340 is provided on the frame 100, and the output end of the sliding motor 340 is rotatably connected to the lead screw nut on the sliding seat 320 through a horizontal lead screw 350. A lifting seat 360 is slidably mounted on the lifting rail 330, and the fine grinding device 400 is mounted on the lifting seat 360. A vertical lead screw 370 is provided on the sliding seat 320, and the vertical lead screw 370 is connected to the lifting seat 360 through a lead screw nut. A lifting motor 380 connected to one end of the vertical lead screw 370 is provided on the sliding seat 320. The sliding track 310 is fixed to the frame 100, resulting in low vibration and deformation resistance. Therefore, during horizontal sliding, it maintains the stability and level of the precision grinding device 400, adapting to the processing planes of different silicon wafer holders 200, thereby accelerating grinding efficiency and avoiding the need to readjust the grinding height of the precision grinding device 400 after processing each silicon wafer on the holder 200. The cooperation between the vertical lead screw 370 and the lifting track 330 effectively adjusts the grinding height of the precision grinding device 400, ensuring convenient processing.

[0053] See Figure 7 As shown, to better achieve grinding, the fine grinding device 400 can be a combination of a motor and a grinding wheel. This structure is simple and low-cost, but the overall structure has poor vibration resistance, making it prone to vibration during grinding, which in turn affects the grinding quality. Therefore, in some possible embodiments, the fine grinding device 400 includes a drive motor 410 and a grinding wheel 420. The drive motor 410 is mounted on a lifting base 360, which has a mounting plate 390. A rotating shaft 430 is rotatably mounted on the mounting plate 390. The grinding wheel 420 is detachably mounted on one end of the rotating shaft 430, and the other end of the rotating shaft 430 meshes with the output end of the drive motor 410 via a gear 440. With this structural arrangement, the grinding wheel 420 and the drive motor 410 are not directly connected, thus reducing vibration transmission between them to some extent. Furthermore, the staggered design facilitates later component maintenance.

[0054] In some possible embodiments, to facilitate automated loading and unloading, a loading / unloading robot is provided on the worktable 110. The loading / unloading robot can be a conventional multi-degree-of-freedom loading / unloading robot, which is not shown in the accompanying drawings and will not be described in detail here. It should be noted that, in this application, because the silicon wafers require ultra-precision grinding, the robot cannot replace manual labor to change the side of the silicon wafers on the clamping fixture for grinding; manual adjustment is still required. Therefore, the loading / unloading robot can only perform loading and unloading functions.

[0055] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An automated ultra-precision grinding equipment for silicon wafers, characterized in that, include: A frame on which a worktable is mounted; A plurality of silicon wafer fixing devices are provided, all of which are mounted on the worktable. Each silicon wafer fixing device includes a plane adjustment mechanism and a level adjustment mechanism. The bottom of the plane adjustment mechanism is slidably mounted on the worktable and can be locked relative to the worktable. The level adjustment mechanism is mounted on the top of the plane adjustment mechanism, and an angle adjustment mechanism is provided on the top of the angle adjustment mechanism. A clamping fixture for fixing the silicon wafer is provided on the top of the angle adjustment mechanism. A spatial displacement device, which is mounted on the frame; A fine grinding device is installed on the adjustment end of the spatial displacement device, and the fine grinding device is capable of grinding all the silicon wafers on the clamping fixture. The leveling adjustment mechanism includes a fixed housing and four lifting screws, which are rotatably mounted on the four corners of the fixed housing. The angle adjustment mechanism is mounted on the top of the fixed housing. The lower ends of the four lifting screws abut against the top of the plane adjustment mechanism. The top of the plane adjustment mechanism is provided with several sliding guide posts, and the fixed housing is provided with several sliding holes that cooperate with the sliding guide posts. The fixed housing can slide on the sliding guide posts but cannot slide out from the top of the sliding guide posts. Two sets of adjustment components are installed on the fixed housing. Each set of adjustment components can cooperate with two of the lifting screws and can independently adjust the extension amount of the lower end of any one of the lifting screws. Each of the adjusting components includes an operating shaft and two worm gears movably mounted on the operating shaft. Both ends of the operating shaft are rotatably mounted on two opposite inner sidewalls of the fixed housing. One end of the operating shaft extends movably through the fixed housing, and the operating shaft can slide on the fixed housing along its axial direction. The end of the operating shaft outside the fixed housing forms the operating end. Each of the two worm gears meshes individually with two lifting screws on the same side. Two sets of friction plates are provided on the area between the two worm gears on the operating shaft. When the operating shaft slides along either end of the axis of the two worm gears, each set of friction plates can only abut against the side of the corresponding worm gear.

2. The automatic ultra-precision grinding equipment for silicon wafers according to claim 1, characterized in that, The friction plate has several friction strips protruding outward on the side near the worm gear, and the worm gear has several grooves that mate with the friction strips on the side near the friction plate.

3. The automatic ultra-precision grinding equipment for silicon wafers according to claim 1, characterized in that, Both ends of the operating shaft are fitted with fixing sleeves. The opposite ends of the two fixing sleeves are rotatably mounted on the inner side wall of the fixed housing. The two worm gears are coaxially mounted on the fixing sleeves. The two worm gears can rotate with the corresponding fixing sleeves. The opposite ends of the two fixing sleeves do not protrude from the opposite side of the corresponding worm gear.

4. The automatic ultra-precision grinding equipment for silicon wafers according to claim 1, characterized in that, The angle adjustment mechanism includes a base and a shaft column mounted on the base. The base is mounted on the top of the fixed housing. The base has a mounting annular groove on the outer periphery of the shaft column. A mounting spacer is provided in the mounting annular groove. A bearing is fitted on the mounting spacer. A rotating ring is fitted on the outer ring of the bearing. A mounting seat is provided on the rotating ring. The clamping fixture is detachably mounted on the mounting seat. A push arm extends outward from the outer wall of the rotating ring. A mounting block extends outward from the base. A limiting groove is provided on the mounting block. One end of the push arm is located in the limiting groove. Fine adjustment rods are screwed onto both sides of the mounting block located in the limiting groove. The opposing ends of the two fine adjustment rods can abut against the side wall of the outward end of the push arm.

5. The automatic ultra-precision grinding equipment for silicon wafers according to claim 1, characterized in that, The planar adjustment mechanism includes a sliding seat, a longitudinal sliding seat slidably mounted on the sliding seat, and a transverse sliding seat slidably mounted on the longitudinal sliding seat. The sliding seat is slidably mounted on the slide rail of the worktable. The sliding seat is provided with a locking knob, which can lock the sliding seat and the slide rail relative to each other. The levelness adjustment mechanism is mounted on the transverse sliding seat. A first fixing block is provided on one side of the longitudinal sliding seat. A first top block is provided on the sliding seat. A first rotating rod is screwed through the first top block, and one end of the first rotating rod is rotatably connected to the first fixing block. A second top block is provided on the longitudinal sliding seat. A second fixing block is provided on the transverse sliding seat. A second rotating rod is screwed through the second top block, and one end of the second rotating rod is rotatably connected to the second fixing block.

6. The automatic ultra-precision grinding equipment for silicon wafers according to claim 1, characterized in that, The spatial displacement device includes a sliding rail mounted on a frame, a sliding seat slidably mounted on the sliding rail, and a lifting rail mounted on the sliding seat. A sliding motor is installed on the frame, and the output end of the sliding motor is rotatably connected to a lead screw nut on the sliding seat via a horizontal lead screw. A lifting seat is slidably mounted on the lifting rail, and the fine grinding device is installed on the lifting seat. A vertical lead screw is installed on the sliding seat, and the vertical lead screw is connected to the lifting seat via a lead screw nut. A lifting motor connected to one end of the vertical lead screw is installed on the sliding seat.

7. The automatic ultra-precision grinding equipment for silicon wafers according to claim 6, characterized in that, The fine grinding device includes a drive motor and a grinding wheel. The drive motor is mounted on the lifting base, and the lifting base is provided with a mounting plate. A rotating shaft is rotatably mounted on the mounting plate. The grinding wheel is detachably mounted on one end of the rotating shaft, and the other end of the rotating shaft meshes with the output end of the drive motor through a gear.

8. The automatic ultra-precision grinding equipment for silicon wafers according to claim 1, characterized in that, The workbench is equipped with a loading and unloading robot.

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