Silicon wafer polishing machine

Abstract

The invention relates to a silicon wafer polishing machine, and relates to the field of polishing equipment, the silicon wafer polishing machine comprises a rack, a rotary table, a main shaft, a driving shaft, a moving seat, a displacement control mechanism, a pressure sensor and a compensation mechanism, the upper end of the driving shaft is in rotation stopping connection with the main shaft, and the upper end of the driving shaft is in sliding connection with the main shaft in the axial direction of the main shaft; the compensation mechanism comprises a displacement driving assembly, a first wedge-shaped block, a second wedge-shaped block and a fixing ring. The inner wall of the fixing ring is connected with the outer wall of the driving shaft through a double-row angular contact ball bearing. The inclined face of the first wedge-shaped block and the inclined face of the second wedge-shaped block are attached to the upper matching plane and the lower matching plane respectively, the displacement driving assembly is used for controlling the first wedge-shaped block and the second wedge-shaped block to move in the radial direction relative to the main shaft, and the moving directions of the first wedge-shaped block and the second wedge-shaped block are opposite. Height fine adjustment can be conducted on the polishing disc, so that it is guaranteed that the pressure of the polishing disc on silicon wafers is stable, and the polishing effect is stable.

Description

Technical Field

[0001] The present application relates to the field of polishing equipment, and in particular to a silicon wafer polishing machine. Background Art

[0002] Surface polishing of silicon wafers is a very important process step in the preparation of semiconductors, micro-electromechanical systems, micro-optoelectronics and other devices. After polishing, the surface of the silicon wafer is very smooth like a mirror, which meets the needs of device preparation.

[0003] The existing polishing device includes a frame, a turntable, a spindle, a movable seat and a displacement control mechanism. The turntable is arranged on the frame, and the turntable is used to fix the silicon wafer. The movable seat is installed on the displacement control mechanism, and the displacement control mechanism is used to control the movable seat to move along the X-axis, Y-axis and Z-axis. The movable seat is fixed with a driving motor, and the driving motor is fixed with a polishing disc through the spindle.

[0004] During the polishing process, the silicon wafer is fixed on a turntable, and the displacement control mechanism drives the polishing disc to move relative to the silicon wafer for polishing. At the same time, during the polishing process, a stable polishing pressure needs to be maintained between the polishing disc and the upper surface of the silicon wafer to ensure the accuracy and quality of the silicon wafer polishing. Especially when the upper surface of the silicon wafer is tilted or uneven, a higher stability requirement for the polishing pressure is required.

[0005] To this end, the existing polishing device also includes a pressure sensor and a compensation mechanism. The pressure sensor is arranged on the polishing disk or turntable, that is, it can detect the downward pressure of the silicon wafer. At the same time, the polishing disk is fixed with a drive shaft, and the drive shaft is connected to the main shaft with a non-rotational sliding connection, that is, the torque of the main shaft can be transmitted to the drive shaft to drive the polishing disk to rotate. This non-rotational sliding connection method often adopts the cooperation form of a guide spline.

[0006] At the same time, the compensation mechanism can drive the drive shaft and the polishing disc to move a small distance axially relative to the main shaft to adjust the pressure of the polishing disc on the silicon wafer, making the pressure as stable as possible to ensure the polishing effect.

[0007] The existing compensation mechanism can be a structure such as a cylinder or an electric push rod that can drive the drive shaft to move linearly over a short distance with high precision.

[0008] However, since the drive shaft and the main shaft are in a sliding fit, there is a certain sliding gap, which can easily lead to a coaxiality difference between the drive shaft and the main shaft, thereby affecting the flatness of the polishing disc and further affecting the polishing effect. Summary of the invention

[0009] In order to improve the stability of the polishing effect, the present application provides a silicon wafer polishing machine.

[0010] The present application provides a silicon wafer polishing machine, which adopts the following technical solution: A silicon wafer polishing machine comprises a frame, a turntable, a spindle, a driving shaft, a moving seat, a displacement control mechanism, a pressure sensor and a compensation mechanism, wherein the turntable is arranged on the frame, the turntable is used to fix and place silicon wafers, the moving seat is installed on the displacement control mechanism, the displacement control mechanism is used to control the moving seat to move along the X-axis, Y-axis and Z-axis, the moving seat is fixed with a driving motor, the spindle is fixed to the output shaft of the driving motor, the upper end of the driving shaft is connected to the spindle for rotation prevention, and the upper end of the driving shaft is connected to the spindle for sliding along the axial direction of the spindle, the lower end of the driving shaft is provided with a polishing disc, and the pressure sensor is arranged on the polishing disc or the turntable; the compensation mechanism comprises a displacement driving component , a first wedge block, a second wedge block and a fixed ring, the inner wall of the fixed ring is connected to the outer wall of the drive shaft by a double-row angular contact ball bearing, the cross-sectional shape of the fixed ring is an isosceles triangle, the upper surface of the fixed ring is composed of a plurality of upper mating planes, and the lower surface of the fixed ring is composed of a plurality of lower mating planes; the plurality of first wedge blocks and the plurality of second wedge blocks are uniformly arranged along the circumference of the fixed ring, the inclined surface of the first wedge block and the inclined surface of the second wedge block are respectively fitted to the upper mating plane and the lower mating plane, and the displacement drive assembly is used to respectively control the radial movement of the first wedge block and the second wedge block relative to the main shaft, and the movement directions of the first wedge block and the second wedge block are opposite.

[0011] By adopting the above technical solution, when the pressure sensor detects the pressure change of the silicon wafer and the height of the polishing disk needs to be fine-tuned, the displacement drive assembly is started, and the displacement drive assembly controls the first wedge block and the second wedge block to move radially relative to the drive shaft, and the movement directions of the first wedge block and the second wedge block are opposite. Specifically, when the polishing disk needs to be slightly lifted, each second wedge block moves radially and inwardly along the drive shaft to support the fixed ring, thereby driving the drive shaft and the polishing disk to move upward. At the same time, each first wedge block moves radially and outwardly along the drive shaft, not only leaving rising space for the fixed ring, but also the inclined surface of the first wedge block is still in contact with the upper mating plane, that is, the first wedge block and the second wedge block clamp the fixed ring at the same time, and the inclined surface cooperates to play a centering role, so that the drive shaft is concentric with the main shaft, thereby ensuring the flatness of the polishing disk, thereby improving the polishing effect.

[0012] When it is necessary to slightly lower the polishing disk, each first wedge block moves radially and inwardly along the drive shaft to force the fixed ring to descend, thereby driving the drive shaft and the polishing disk to move downward. At the same time, each second wedge block moves radially and outwardly along the drive shaft, not only leaving space for the fixed ring to move downward, but also the inclined surface of the second wedge block still fits the lower mating plane, that is, the first wedge block and the second wedge block clamp the fixed ring at the same time, and the inclined surface cooperates to play a centering role, so that the drive shaft and the main shaft are concentric.

[0013] In summary, by setting the displacement drive assembly, the first wedge block, the second wedge block and the fixed ring, the first wedge block and the second wedge block move in opposite directions to control the slight rise and fall of the fixed ring and the polishing disk, thereby adjusting the pressure of the polishing disk on the upper surface of the silicon wafer, so that the pressure is stable and the polishing effect is stable. In addition, the first wedge block and the second wedge block always clamp the fixed ring, and the inclined surface cooperates to play a centering role, so that the drive shaft is concentric with the main shaft, thereby ensuring the flatness of the polishing disk, and then improving the polishing effect.

[0014] Optionally, the number of the first wedge blocks and the number of the second wedge blocks are both even numbers.

[0015] By adopting the above technical solution, the centering effect is more stable.

[0016] Optionally, the inclined surfaces of the first wedge-shaped block and the second wedge-shaped block are both provided with a chrome-plated layer.

[0017] By adopting the above technical solution, the wear resistance can be improved, thereby improving the matching accuracy.

[0018] Optionally, the compensation mechanism also includes a fixed cylinder, which is fixed to the movable seat and coaxially arranged with the main shaft; the displacement drive assembly includes a plurality of cylinders, the cylinder bodies of the cylinders are installed on the fixed cylinder, the telescopic direction of the cylinders is the radial direction of the fixed cylinder, and the pistons of each cylinder are fixedly connected to the first wedge block and the second wedge block respectively.

[0019] By adopting the above technical solution, a plurality of cylinders are provided to respectively control the linear movement of the first wedge block and the second wedge block, and the response speed is fast.

[0020] Optionally, the compensation mechanism also includes a fixed cylinder, which is fixed to the movable seat and coaxially arranged with the main shaft; the displacement drive assembly includes a rotating rod, a lever and a driving structure, the first wedge block and the second wedge block are both radially slidingly connected to the fixed cylinder, the rotating rod and the fixed cylinder are rotatably arranged, the axial level of the rotating rod is perpendicular to the radial direction of the fixed cylinder, the midpoint of the lever is fixedly connected to the rotating rod, the rotation plane of the lever is the radial plane of the fixed cylinder, and the driving structure is used to control the rotation angle of the rotating rod; the first wedge block and the second wedge block are both fixed with connecting arms, and both ends of the lever are slidingly connected with sliding tubes along their own length direction, and the ends of the two sliding tubes are respectively hingedly connected to the two connecting arms.

[0021] By adopting the above technical solution, a rotating rod, a lever, and a driving structure are set. The driving structure controls the rotation angle of the rotating rod and the lever is deflected, thereby driving one of the connecting arms to move toward the axis of the fixed ring and driving the other connecting arm to move away from the axis of the fixed ring, so that the first wedge block and the second wedge block move synchronously, equidistantly and in opposite directions, so that the fixed ring and the polishing disk are slightly raised or lowered.

[0022] Optionally, the driving structure includes a worm wheel, a worm, an inner gear ring, an outer gear ring and a control motor, wherein the worm wheel is coaxially fixed on the rotating rod, the worm is parallel to the axial direction of the fixed cylinder, the worm is rotatably arranged with the fixed cylinder, the worm is meshed with the worm wheel, a first gear is fixed to the upper end of the worm, both the inner gear ring and the outer gear ring are rotatably arranged with the movable seat, the outer gear ring and the inner gear ring are coaxial with the fixed cylinder, the inner gear ring and the outer gear ring are fixedly arranged, the inner gear ring is meshed with each first gear, the control motor is installed on the movable seat, and the output shaft of the control motor is fixed with a second gear meshed with the outer gear ring.

[0023] By adopting the above technical solution, the outer gear ring and the inner gear ring are driven to rotate by controlling the motor, and the inner gear ring drives each worm to rotate through the first gear. The worm gear and the worm gear cooperate to change the angle of the worm wheel and the rotating rod, so as to change the deflection angle of the lever, so that the first wedge block and the second wedge block move synchronously, equidistantly and in opposite directions, thereby causing the fixing ring and the polishing disk to rise or fall slightly.

[0024] Optionally, the fixing ring includes two unit rings symmetrically arranged in the upper and lower parts, the inner circumference of the unit rings is fitted to the outer circumference of the outer ring of the double-row angular contact ball bearing, the two unit rings respectively have the upper mating plane and the lower mating plane, and there is an axial gap between the opposite surfaces of the two unit rings; the outer circumference of the outer ring of the double-row angular contact ball bearing is provided with an annular groove, and two axially stacked first steel sheet rings are provided in the annular groove, and the outer circumference of the first steel sheet ring is integrally formed with a plurality of inclined first claws, and the first claws of the two first steel sheet rings are elastically pressed against the opposite surfaces of the two unit rings respectively.

[0025] By adopting the above technical solution and setting the elastic abutment of the first claw, the two unit rings have a tendency to move axially apart, so that the upper mating plane and the lower mating plane fit more flatly with the inclined surfaces of the first wedge block and the second wedge block, and the lifting and lowering accuracy of the fixed ring is higher.

[0026] Optionally, the fixing ring includes two unit rings symmetrically arranged in the upper and lower parts, the inner circumference of the unit rings is fitted to the outer circumference of the outer ring of the double-row angular contact ball bearing, the two unit rings respectively have the upper mating plane and the lower mating plane, there is an axial gap between the opposite surfaces of the two unit rings, and two disc springs are arranged in the axial gap; the outer circumference of the outer ring of the double-row angular contact ball bearing is provided with an annular groove, a second steel sheet ring is arranged in the annular groove, the outer circumference of the second steel sheet ring is integrally formed with a plurality of inclined second claws and third claws, the inclination directions of the second claws and the third claws are different, the second claws and the third claws are elastically pressed against the opposite surfaces of the two unit rings respectively; the small ends of the two disc springs are pressed against each other, the large ends of the two disc springs are pressed against the opposite surfaces of the two unit rings respectively, and the disc spring is located between the second claw and the third claw.

[0027] By adopting the above technical solution and arranging the elastic abutment of the disc spring, the second claw and the third claw, the two unit rings have a tendency to move axially apart, so that the upper mating plane and the lower mating plane fit more flatly with the inclined surfaces of the first wedge block and the second wedge block, and the lifting and lowering accuracy of the fixed ring is higher.

[0028] Secondly, the cooperation between the disc spring and the second claw and the third claw respectively increases the difficulty of axial compression of the unit ring, that is, the rigidity of the unit ring is stronger, and the cooperation between the unit ring and the first wedge block and the second wedge block is more stable.

[0029] In addition, the second claw and the third claw are both located on the same second steel sheet ring, and the disc spring is located between the second claw and the third claw. Therefore, the disc spring will constrain the deformation displacement of the second claw and the third claw, and ensure that the deformation displacement of the second claw and the third claw is relatively consistent and adapted to the axial deformation degree of the disc spring itself, which not only increases the rigidity, but also ensures the consistency of deformation, making the position of the fixing ring more accurate.

[0030] In summary, the present application includes at least one of the following beneficial technical effects: By setting a displacement drive assembly, a first wedge block, a second wedge block and a fixed ring, the first wedge block and the second wedge block move in opposite directions to control the slight rise and fall of the fixed ring and the polishing disc, thereby adjusting the pressure of the polishing disc on the upper surface of the silicon wafer, so that the pressure is stable and the polishing effect is stable. In addition, the first wedge block and the second wedge block always clamp the fixed ring, and through the inclined surface cooperation, they play a centering role, so that the drive shaft is concentric with the main shaft, thereby ensuring the flatness of the polishing disc, thereby improving the polishing effect; By setting a rotating rod, a lever, and a driving structure, the driving structure controls the rotation angle of the rotating rod and the lever is deflected, thereby driving one of the connecting arms to move in a direction toward the axis of the fixed ring and driving the other connecting arm to move in a direction away from the axis of the fixed ring, so that the first wedge block and the second wedge block move synchronously, equidistantly and in opposite directions, so that the fixed ring and the polishing disk are slightly raised or lowered. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the overall structure of Example 1.

[0032] Figure 2 It is a schematic diagram of the internal structure of the silicon wafer polishing machine of Example 1.

[0033] Figure 3 It is a cross-sectional view of the compensation mechanism of Example 1.

[0034] Figure 4 yes Figure 3 A partial enlarged view of point A in the middle.

[0035] Figure 5 Schematic diagram of the fixing ring of Example 1.

[0036] Figure 6 It is a schematic diagram of Example 1 for showing that the fixing ring is in a slightly elevated state.

[0037] Figure 7 It is a cross-sectional view of the compensation mechanism of Example 2.

[0038] Figure 8 yes Figure 7 A partial enlarged view of point B in the middle.

[0039] Fig. 9 It is a top view of Example 2, which is used to reflect the positional relationship between the worm gear and the rotating rod.

[0040] Fig.10 It is a schematic diagram of Example 3 for reflecting the positional relationship between two unit rings.

[0041] Fig.11 It is a schematic diagram of Example 4 for reflecting the positional relationship between two unit rings.

[0042] Explanation of the reference numerals: 1. fixed ring; 2. displacement drive assembly; 3. fixed cylinder; 10. frame; 101. turntable; 1000. unit ring; 1011. fixture; 102. displacement control mechanism; 1021. X-axis moving module; 1022. Y-axis moving module; 1023. Z-axis moving module; 100. moving seat; 110. driving motor; 11. first wedge block; 12. second wedge block; 120. main shaft; 121. inner hole; 122. keyway; 130. driving shaft; 131. key block; 132. double-row angular contact ball bearing; 133. ring groove; 150. upper mating plane; 160. lower mating plane surface; 20, polishing disc; 201, pressure sensor; 202, connecting column; 203, support spring; 21, cylinder; 22, rotating rod; 23, lever; 25, driving structure; 251, worm gear; 252, worm; 253, control motor; 254, second gear; 255, outer gear ring; 256, inner gear ring; 257, first gear; 26, connecting arm; 261, slide groove; 27, slide tube; 31, avoidance hole; 32, connecting plate; 321, slider; 33, rotating seat; 51, first steel ring; 52, first clamping claw; 53, second steel ring; 54, second clamping claw; 55, third clamping claw; 56, disc spring. DETAILED DESCRIPTION

[0043] The following is combined with Figure 1-11 This application is described in further detail.

[0044] Embodiment 1, Embodiment 1 discloses a silicon wafer polishing machine. Figure 1 , Figure 2 and Figure 3 The silicon wafer polishing machine comprises a frame 10, a turntable 101, a spindle 120, a driving shaft 130, a moving seat 100, a displacement control mechanism 102, a pressure sensor 201 and a compensation mechanism. The turntable 101 is arranged on the frame 10, the frame 10 is provided with a motor (not shown in the figure) for driving the turntable 101 to rotate, the upper surface of the turntable 101 is used to fix and place the silicon wafer, and the turntable 101 is provided with a clamp 1011 for clamping the silicon wafer.

[0045] The moving seat 100 is installed on the displacement control mechanism 102. The displacement control mechanism 102 includes an X-axis moving module 1021, a Y-axis moving module 1022 and a Z-axis moving module 1023. The displacement control mechanism 102 is used to control the moving seat 100 to move along the X-axis, Y-axis and Z-axis.

[0046] The movable seat 100 is fixed with a driving motor 110, the main shaft 120 is fixed to the output shaft of the driving motor 110, and the upper end of the driving shaft 130 is connected to the main shaft 120 in a non-rotating and sliding manner. Specifically, an inner hole 121 is opened at the lower end of the main shaft 120, and the inner wall of the inner hole 121 is provided with a plurality of key grooves 122 evenly arranged circumferentially, and the key groove 122 is opened along the axial direction of the main shaft 120. A key block 131 is fixed to the outer peripheral surface of the upper part of the driving shaft 130, and the key block 131 extends along the axial direction of the driving shaft 130. There are multiple key blocks 131 and they are slidably matched with the key groove 122 one by one, that is, through the cooperation of the key block 131 and the key groove 122, the torque of the main shaft 120 can be transmitted to the driving shaft 130, and at the same time, the driving shaft 130 is allowed to move axially for a short distance relative to the main shaft 120.

[0047] A polishing disk 20 is provided at the lower end of the driving shaft 130, and the polishing disk 20 is higher than the turntable 101. The pressure sensor 201 is provided on the polishing disk 20 or the turntable 101. In other embodiments, the pressure sensor 201 is provided on the turntable 101 to detect the downward pressure exerted on the silicon wafer. In another embodiment, the pressure sensor 201 is directly fixed between the polishing disk 20 and the driving shaft 130 to detect the downward pressure exerted by the polishing disk 20 on the silicon wafer.

[0048] In this embodiment, a connecting column 202 is fixed to the upper end of the polishing disk 20, and the connecting column 202 is connected to the lower end of the driving shaft 130 in a non-rotational and sliding manner. The specific structure of the non-rotational and sliding connection is consistent with the non-rotational and sliding structure of the main shaft 120, and the pressure sensor 201 is annular. The pressure sensor 201 is sleeved on the outside of the connecting column 202, and the upper end surface of the pressure sensor 201 is against the lower end surface of the driving shaft 130. The connecting column 202 is also sleeved with a support spring 203, and the lower end of the support spring 203 is against the upper part of the polishing disk 20, and the upper end of the support spring 203 is against the lower end surface of the pressure sensor 201, that is, the pressure of the polishing disk 20 can be transmitted to the pressure sensor 201 through the support spring 203, and the pressure sensor 201 is used to detect the pressure of the polishing disk 20.

[0049] When the pressure sensor 201 detects a change in the polishing pressure, the compensation mechanism is used to drive the drive shaft 130 to move axially for a short distance to adjust the polishing pressure of the polishing disc 20 so that the polishing pressure is stable. Specifically, Figure 3 , Figure 4 , Figure 5 As shown, the compensation mechanism includes a fixed cylinder 3, a displacement driving assembly 2, a first wedge block 11, a second wedge block 12 and a fixed ring 1, wherein the upper end of the fixed cylinder 3 is fixed to the movable seat 100, the fixed cylinder 3 is coaxially arranged with the main shaft 120, and the fixed cylinder 3 is located on the outside of the driving shaft 130.

[0050] The inner wall of the fixing ring 1 and the outer wall of the driving shaft 130 are connected via a double-row angular contact ball bearing 132, that is, the inner wall of the fixing ring 1 is fixed to the outer ring of the double-row angular contact ball bearing 132, and the outer wall of the driving shaft 130 is fixed to the inner ring of the double-row angular contact ball bearing 132, so that the fixing ring 1 and the driving shaft 130 are coaxially arranged, and the rotation of the driving shaft 130 will not cause the fixing ring 1 to rotate. At the same time, the axial movement of the fixing ring 1 will also drive the driving shaft 130 to move axially.

[0051] like Figure 4 , Figure 5 As shown, the cross-section of the fixing ring 1 is an isosceles triangle, the upper surface of the fixing ring 1 is composed of a plurality of upper matching planes 150 , and the lower surface of the fixing ring 1 is composed of a plurality of lower matching planes 160 .

[0052] The first wedge block 11 and the second wedge block 12 are provided in a plurality. In the present embodiment, the number of the first wedge block 11 and the second wedge block 12 are both an even number, and the inclined surfaces of the first wedge block 11 and the second wedge block 12 are both provided with a chrome-plated layer (not shown in the figure).

[0053] The plurality of first wedge blocks 11 and the plurality of second wedge blocks 12 are uniformly arranged along the circumference of the fixing ring 1 , and the inclined surfaces of the first wedge blocks 11 and the inclined surfaces of the second wedge blocks 12 are respectively fitted to the upper mating plane 150 and the lower mating plane 160 .

[0054] The displacement drive assembly 2 is used to control the radial movement of the first wedge block 11 and the second wedge block 12 relative to the main shaft 120, and the movement directions of the first wedge block 11 and the second wedge block 12 are opposite. In this embodiment, the displacement drive assembly 2 includes a plurality of cylinders 21, the cylinder bodies of the cylinders 21 are installed on the fixed cylinder 3, the extension direction of the cylinders 21 is the radial direction of the fixed cylinder 3, and the pistons of the cylinders 21 are fixedly connected to the first wedge block 11 and the second wedge block 12, respectively, that is, the radial movement of the first wedge block 11 and the second wedge block 12 relative to the main shaft 120 is controlled by the extension and contraction of the cylinders 21.

[0055] The implementation principle of Example 1 is as follows: when the pressure sensor 201 detects the pressure change of the silicon wafer and the height of the polishing plate 20 needs to be fine-tuned, the displacement drive assembly 2 is started, and the displacement drive assembly 2 controls the first wedge block 11 and the second wedge block 12 to move radially relative to the drive shaft 130, and the movement directions of the first wedge block 11 and the second wedge block 12 are opposite. Specifically, when the polishing plate 20 needs to be slightly raised, each second wedge block 12 moves radially and inwardly along the drive shaft 130 to support the fixing ring 1, thereby driving the drive shaft 130 and the polishing plate 20 to move upward (see Figure 6), at the same time, each first wedge block 11 moves radially and outwardly along the driving shaft 130, not only leaving rising space for the fixed ring 1, but also the inclined surface of the first wedge block 11 is still in contact with the upper matching plane 150, that is, the first wedge block 11 and the second wedge block 12 simultaneously clamp the fixed ring 1, and the inclined surface cooperates to play a centering role, so that the driving shaft 130 is concentric with the main shaft 120, thereby ensuring the flatness of the polishing disc 20 and improving the polishing effect.

[0056] When it is necessary to slightly lower the polishing disk 20, each first wedge block 11 moves radially and inwardly along the drive shaft 130 to force the fixed ring 1 to descend, thereby driving the drive shaft 130 and the polishing disk 20 to move downward. At the same time, each second wedge block 12 moves radially and outwardly along the drive shaft 130, not only leaving space for the fixed ring 1 to move downward, but also the inclined surface of the second wedge block 12 is still in contact with the lower mating plane 160, that is, the first wedge block 11 and the second wedge block 12 clamp the fixed ring 1 at the same time, and the inclined surface cooperates to play a centering role, so that the drive shaft 130 is concentric with the main shaft 120.

[0057] In summary, by setting the displacement drive assembly 2, the first wedge block 11, the second wedge block 12 and the fixed ring 1, the first wedge block 11 and the second wedge block 12 move in opposite directions to control the slight rise and fall of the fixed ring 1 and the polishing disk 20, so as to adjust the pressure of the polishing disk 20 on the upper surface of the silicon wafer, so that the pressure is stable and the polishing effect is stable. In addition, the first wedge block 11 and the second wedge block 12 always clamp the fixed ring 1, and the inclined surface cooperates to play a centering role, so that the drive shaft 130 is concentric with the main shaft 120, so as to ensure the flatness of the polishing disk 20, thereby improving the polishing effect.

[0058] Embodiment 2, embodiment 2 is different from embodiment 1 in that, Figure 7 , Figure 8 , Fig. 9 As shown, the displacement drive assembly 2 includes a rotating rod 22, a lever 23 and a driving structure 25. The first wedge block 11 and the second wedge block 12 are both radially slidingly connected to the fixed cylinder 3. Specifically, the first wedge block 11 and the second wedge block 12 are both fixed with a connecting arm 26, and the direction of the connecting arm 26 is the radial direction of the fixed cylinder 3. A plurality of radially extending connecting plates 32 are fixed to the inner wall of the fixed cylinder 3. The connecting plates 32 are arranged in a one-to-one correspondence with the connecting arms 26. The surface of the connecting arm 26 is provided with a sliding groove 261 extending along its own length direction. The connecting plate 32 is fixed with a slider 321. Through the cooperation of the slider 321 and the sliding groove 261, the first wedge block 11 and the second wedge block 12 are respectively connected to the fixed cylinder 3 in a radially sliding manner.

[0059] The fixed cylinder 3 is provided with an avoidance hole 31 , in which the rotating rod 22 is located. Both ends of the rotating rod 22 are inserted into the hole wall of the avoidance hole 31 , so that the rotating rod 22 is rotationally linked to the fixed cylinder 3 , and the axial direction of the rotating rod 22 is perpendicular to the radial direction of the fixed cylinder 3 .

[0060] The midpoint of the lever 23 is fixedly connected to the rotating rod 22, and the lever 23 is perpendicular to the rotating rod 22, so that the rotation plane of the lever 23 is coplanar with the radial plane of the fixed cylinder 3; both ends of the lever 23 are slidably connected with sliding tubes 27 along their own length direction, and the ends of the two sliding tubes 27 are respectively hingedly connected to the two connecting arms 26.

[0061] The driving structure 25 is used to control the rotation angle of the rotating rod 22. Specifically, the driving structure 25 includes a worm wheel 251, a worm 252, an inner gear ring 256, an outer gear ring 255 and a control motor 253, wherein the worm wheel 251 is coaxially fixed on the rotating rod 22, the worm 252 is parallel to the axial direction of the fixed cylinder 3, a rotating seat 33 is fixed on the outer wall of the fixed cylinder 3, the worm 252 is rotatably connected to the rotating seat 33, and the worm 252 is meshed with the worm wheel 251.

[0062] A first gear 257 is fixed to the upper end of the worm 252. The inner gear ring 256 and the outer gear ring 255 are both rotatably arranged with the bottom of the movable seat 100. The outer gear ring 255 and the inner gear ring 256 are both coaxial with the fixed cylinder 3. The inner gear ring 256 and the outer gear ring 255 are fixedly arranged, and the inner gear ring 256 is meshed with the first gear 257 of each worm 252.

[0063] The control motor 253 is installed on the moving base 100 . The output shaft of the control motor 253 is fixed with a second gear 254 . The second gear 254 is meshed with the outer gear ring 255 .

[0064] The control motor 253 drives the outer ring gear 255 and the inner ring gear 256 to rotate through the second gear 254, and the inner ring gear 256 drives each worm 252 to rotate through the first gear 257. The worm wheel 251 and the worm 252 cooperate to achieve the angle change of the worm wheel 251 and the rotating rod 22, so as to achieve the change of the deflection angle of the lever 23. The angular deflection of the lever 23 will drive one of the connecting arms 26 to move in the direction toward the axis of the fixed ring 1, and at the same time drive the other connecting arm 26 to move in the direction away from the axis of the fixed ring 1, so that the first wedge block 11 and the second wedge block 12 move synchronously, equidistantly and in opposite directions, so that the fixed ring 1 and the polishing disk 20 are slightly raised or lowered.

[0065] Embodiment 3, embodiment 3 is different from embodiment 1 in that, Fig.10As shown, the fixing ring 1 is composed of two unit rings 1000 symmetrically arranged up and down. The inner circumference of the unit ring 1000 is in contact with the outer circumference of the outer ring of the double-row angular contact ball bearing 132, that is, the unit ring 1000 can move axially a certain distance relative to the double-row angular contact ball bearing 132.

[0066] The two unit rings 1000 respectively have an upper mating plane 150 and a lower mating plane 160 , and an axial gap is provided between the opposite surfaces of the two unit rings 1000 .

[0067] An annular groove 133 is provided on the outer peripheral surface of the outer ring of the double-row angular contact ball bearing 132, and two axially stacked first steel rings 51 are fixed in the annular groove 133. The outer peripheral surface of the first steel ring 51 is integrally formed with a plurality of inclined first claws 52, and each first claw 52 is evenly arranged along the circumference of the first steel ring 51, and the inclination directions of the first claws 52 of the two first steel rings 51 are different. The first claws 52 of the two first steel rings 51 are elastically pressed against the opposite surfaces of the two unit rings 1000 respectively.

[0068] That is, by setting the elastic abutment of the first claw 52, ​​the two unit rings 1000 have a tendency to move axially apart, so that the upper matching plane 150 and the lower matching plane 160 fit more flatly with the inclined surfaces of the first wedge block 11 and the second wedge block 12, and the lifting accuracy of the fixing ring 1 is higher.

[0069] In addition, the unit ring 1000 forms an axial limit with the double-row angular contact ball bearing 132 through the first claw 52 and the first steel ring 51. When the two unit rings 1000 rise or fall synchronously, the double-row angular contact ball bearing 132 and the drive shaft 130 will also rise or fall synchronously.

[0070] Embodiment 4, embodiment 4 is different from embodiment 3 in that, Fig.11 As shown, a second steel sheet ring 53 is fixed in the annular groove 133, and a plurality of second claws 54 and third claws 55 are integrally formed on the outer peripheral surface of the second steel sheet ring 53. The second claws 54 and the third claws 55 have different inclination directions, and each second claw 54 and each third claw 55 is evenly staggered along the circumference of the first steel sheet ring 51, and the second claws 54 and the third claws 55 are elastically pressed against the opposite surfaces of the two unit rings 1000 respectively.

[0071] Two disc springs 56 are provided in the axial gap between the opposite surfaces of the two unit rings 1000. The disc springs 56 are coaxially arranged with the unit rings 1000. The large ends of the two disc springs 56 are respectively abutted against the opposite surfaces of the two unit rings 1000, and the small ends of the two disc springs 56 are abutted against each other (the large end of the disc spring 56 is the end surface with a larger diameter, and the small end of the disc spring 56 is the end surface with a smaller diameter), and the disc springs 56 are located in the angle area between the second clamping claw 54 and the third clamping claw 55.

[0072] By setting the relative positions of the second claw 54, the third claw 55 and the disc spring 56, the disc spring 56 will constrain the deformation displacement of the second claw 54 and the third claw 55, and ensure that the deformation displacement of the second claw 54 and the third claw 55 is relatively consistent and adapted to the axial deformation degree of the disc spring 56 itself, so that the position of the fixing ring 1 is more accurate.

[0073] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A silicon wafer polishing machine, characterized in that: The invention comprises a frame (10), a turntable (101), a main shaft (120), a driving shaft (130), a moving seat (100), a displacement control mechanism (102), a pressure sensor (201) and a compensation mechanism, wherein the turntable (101) is arranged on the frame (10), the turntable (101) is used to fix and place silicon wafers, the moving seat (100) is installed on the displacement control mechanism (102), and the displacement control mechanism (102) is used to control the moving seat (100) to move along the X-axis, the Y-axis and The Z-axis moves, the moving seat (100) is fixed with a driving motor (110), the main shaft (120) is fixed to the output shaft of the driving motor (110), the upper end of the driving shaft (130) is connected to the main shaft (120) in a rotation-proof manner, and the upper end of the driving shaft (130) is connected to the main shaft (120) in an axially sliding manner along the main shaft (120), the lower end of the driving shaft (130) is provided with a polishing disc (20), and the pressure sensor (201) is arranged on the polishing disc (20) or the turntable (101) The compensation mechanism comprises a displacement drive assembly (2), a first wedge block (11), a second wedge block (12) and a fixed ring (1); the inner wall of the fixed ring (1) is connected to the outer wall of the drive shaft (130) via a double-row angular contact ball bearing (132); the cross-sectional shape of the fixed ring (1) is an isosceles triangle; the upper surface of the fixed ring (1) is composed of a plurality of upper mating planes (150); the lower surface of the fixed ring (1) is composed of a plurality of lower mating planes (160); the plurality of first wedge blocks (11) and the second wedge blocks (12) are connected to the inner wall of the fixed ring (1) and the outer wall of the drive shaft (130) via a double-row angular contact ball bearing (132); the cross-sectional shape of the fixed ring (1) is an isosceles triangle; the upper surface of the fixed ring (1) is composed of a plurality of upper mating planes (150); the lower surface of the fixed ring (1) is composed of a plurality of lower mating planes (160); The first wedge block (11) and the plurality of second wedge blocks (12) are uniformly arranged along the circumference of the fixed ring (1); the inclined surface of the first wedge block (11) and the inclined surface of the second wedge block (12) are respectively fitted to the upper mating plane (150) and the lower mating plane (160); the displacement drive assembly (2) is used to respectively control the radial movement of the first wedge block (11) and the second wedge block (12) relative to the main shaft (120); and the movement directions of the first wedge block (11) and the second wedge block (12) are opposite.

2. The silicon wafer polishing machine according to claim 1, characterized in that: The number of the first wedge blocks (11) and the number of the second wedge blocks (12) are both even numbers.

3. The silicon wafer polishing machine according to claim 1, characterized in that: The inclined surfaces of the first wedge-shaped block (11) and the second wedge-shaped block (12) are both provided with a chrome-plated layer.

4. The silicon wafer polishing machine according to any one of claims 1 to 3, characterized in that: The compensation mechanism further comprises a fixed cylinder (3), the fixed cylinder (3) being fixed to the movable seat (100), and the fixed cylinder (3) being coaxially arranged with the main shaft (120); the displacement drive assembly (2) comprises a plurality of cylinders (21), the cylinder bodies of the cylinders (21) being mounted on the fixed cylinder (3), the telescopic direction of the cylinders (21) being the radial direction of the fixed cylinder (3), and the pistons of the cylinders (21) being respectively fixedly connected to the first wedge block (11) and the second wedge block (12).

5. The silicon wafer polishing machine according to any one of claims 1 to 3, characterized in that: The compensation mechanism further comprises a fixed cylinder (3), the fixed cylinder (3) is fixed to the movable seat (100), and the fixed cylinder (3) is coaxially arranged with the main shaft (120); the displacement drive assembly (2) comprises a rotating rod (22), a lever (23) and a driving structure (25), the first wedge block (11) and the second wedge block (12) are both radially slidably connected to the fixed cylinder (3), the rotating rod (22) is rotatably arranged with the fixed cylinder (3), and the axial direction of the rotating rod (22) is perpendicular to the fixed cylinder (100). In the radial direction of the fixed cylinder (3), the midpoint of the lever (23) is fixedly connected to the rotating rod (22), the rotation plane of the lever (23) is the radial plane of the fixed cylinder (3), and the driving structure (25) is used to control the rotation angle of the rotating rod (22); the first wedge block (11) and the second wedge block (12) are both fixed with connecting arms (26), and both ends of the lever (23) are slidably connected with sliding tubes (27) along their own length direction, and the ends of the two sliding tubes (27) are respectively hingedly connected to the two connecting arms (26).

6. The silicon wafer polishing machine according to claim 5, characterized in that: The driving structure (25) comprises a worm wheel (251), a worm (252), an inner gear ring (256), an outer gear ring (255) and a control motor (253), wherein the worm wheel (251) is coaxially fixed to the rotating rod (22), the worm (252) is parallel to the axial direction of the fixed cylinder (3), the worm (252) and the fixed cylinder (3) are rotatably arranged, the worm (252) and the worm wheel (251) are meshed, a first gear (257) is fixed to the upper end of the worm (252), and the inner gear ring (255) is fixed to the outer gear ring (256). The gear ring (256) and the outer gear ring (255) are both rotatably arranged with the movable seat (100), the outer gear ring (255) and the inner gear ring (256) are both coaxial with the fixed cylinder (3), the inner gear ring (256) and the outer gear ring (255) are fixedly arranged, the inner gear ring (256) is meshed with each first gear (257), the control motor (253) is installed on the movable seat (100), and the output shaft of the control motor (253) is fixed with a second gear (254) meshed with the outer gear ring (255).

7. The silicon wafer polishing machine according to any one of claims 1 to 3, characterized in that: The fixing ring (1) comprises two unit rings (1000) symmetrically arranged in an upper and lower manner, the inner circumference of the unit ring (1000) being fitted to the outer circumference of the outer ring of the double-row angular contact ball bearing (132), the two unit rings (1000) respectively having the upper mating plane (150) and the lower mating plane (160), and an axial gap being provided between the opposite surfaces of the two unit rings (1000); the outer circumference of the outer ring of the double-row angular contact ball bearing (132) being provided with an annular groove (133), two axially stacked first steel sheet rings (51) being provided in the annular groove (133), the outer circumference of the first steel sheet ring (51) being integrally formed with a plurality of inclined first claws (52), the first claws (52) of the two first steel sheet rings (51) respectively elastically abutting against the opposite surfaces of the two unit rings (1000).

8. The silicon wafer polishing machine according to any one of claims 1 to 3, characterized in that: The fixing ring (1) comprises two unit rings (1000) symmetrically arranged in an upper and lower manner, the inner circumference of the unit ring (1000) is fitted to the outer circumference of the outer ring of the double-row angular contact ball bearing (132), the two unit rings (1000) respectively have the upper matching plane (150) and the lower matching plane (160), an axial gap is provided between the opposite surfaces of the two unit rings (1000), and two disc springs (56) are provided in the axial gap; the outer circumference of the outer ring of the double-row angular contact ball bearing (132) is provided with an annular groove (133), and a second steel sheet is provided in the annular groove (133) The outer peripheral surface of the second steel sheet ring (53) is integrally formed with a plurality of second claws (54) and third claws (55) which are arranged obliquely, and the second claws (54) and the third claws (55) have different inclination directions, and the second claws (54) and the third claws (55) are elastically pressed against the opposite surfaces of the two unit rings (1000) respectively; the small ends of the two disc springs (56) are pressed against each other, and the large ends of the two disc springs (56) are pressed against the opposite surfaces of the two unit rings (1000) respectively, and the disc spring (56) is located between the second claws (54) and the third claws (55).

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