JP2004255483A - Polishing device and polishing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve polishing accuracy, in a polishing device for polishing a work with rotation of an upper polishing plate revolving with a carrier. <P>SOLUTION: This polishing device is provided with the upper polishing plate 35(b) which abuts on the top surface of the carrier 100(a), which is engaged with a sun gear 11 and an internal gear 12 for revolution and while which rotates on a lower polishing plate 13, and similarly revolves with the carrier 100 and while rotates at a rotating speed different from the carrier 100. Relative position of the upper polishing plate 35 and the carrier 100 are provided (d) so that position of a rotary shaft of the upper polishing plate 35 is displaced by the predetermined distance in the revolving direction from a position of the rotary shaft of the carrier 100, on which the upper polishing plate 35 abuts. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technique for improving polishing accuracy in a polishing apparatus.
[0002]
[Prior art]
Conventionally, as a polishing apparatus for polishing a non-abrasive body called a work, for example, a carrier holding a work is disposed between a lower surface plate and an upper surface plate provided for each carrier, and a sun gear and an internal gear are provided. 2. Description of the Related Art A double-side polishing apparatus is known which grinds the upper and lower surfaces of a work held on a carrier by rotating the upper platen and the carrier at a rotation speed different from that of the carrier while revolving in the same manner as the carrier while revolving and rotating in the same manner as the carrier. ing.
[0003]
FIG. 5 schematically shows the structure of such a double-side polishing apparatus.
In the figure, a is a diagram schematically illustrating the arrangement of the sun gear 1, the internal gear 2, the lower stool 3, the carrier 4, and the upper stool 6, as viewed from the vertical direction.
As shown in the figure, each carrier 4 meshes with a tooth array provided on the outer circumference of the sun gear 1 and a tooth array provided on the inner circumference of the internal gear 2 by a tooth array provided on the outer periphery thereof. By rotating the sun gear 1, it revolves around the center of the carrier 4 while revolving around the sun gear 1. On the other hand, the upper stool 6 provided in a one-to-one relationship with the carrier 4 revolves in the same manner as the carrier 4, and the rotation speed of the carrier 4 is equal to the rotation axis of the carrier 4. Spins at different rotational speeds.
[0004]
Next, b in the figure schematically shows the structure of the double-side polishing apparatus viewed from the horizontal direction.
As shown in the figure, the double-side polishing apparatus has an upper stool holding part 5 that moves up and down in the vertical direction. The upper stool holding part 5 holds a plurality of upper stools 6. During polishing, the upper platen holder 5 is lowered so that the rotation axis of the carrier 4 disposed on the lower platen 3 and the rotation axis of the upper platen 6 coincide. By rotating the lower platen 3 and rotating the sun gear 1 while supplying the abrasive, the work is revolved and rotated together with the carrier 4 and the upper platen holder 5 is rotated at the same speed as the revolving speed of the carrier. The upper platen 6 is rotated by rotating the upper platen 6 with respect to the upper platen holder 5 while rotating at a rotational speed. Thus, the upper and lower surfaces of the work held by the carrier 4 are polished by the upper stool 6 and the lower stool 3. In such a double-side polishing apparatus, the internal gear 2 may be further rotated.
[0005]
Next, the structure of the carrier 4 in such a conventional double-side polishing apparatus is shown in FIG. In the drawing, c1 is a top view of the carrier, c2 is a side view, and c3 is a cross-sectional view taken along a vertical plane passing through the center of the carrier.
As shown in the drawing, each carrier 4 has a shape in which the height of the outer edge portion 41 is higher than that of the work holding portion 42 inside the carrier 4 in order to increase the strength. The work holding portion 42 is provided with a through hole for holding the work in the horizontal direction, and the height of the work holding portion 42 is smaller than the target polishing thickness of the work. Further, the carrier outer edge portion 41 has a cylindrical shape having a just thickness, and a tooth row is provided on an outer periphery thereof.
[0006]
[Problems to be solved by the invention]
According to the conventional double-side polishing apparatus shown in FIG. 5, the upper surface of the work is polished only by the relative movement between the upper platen 6 and the carrier 4. Since the rotation axis of the upper stool 6 and the carrier 4 coincide with each other, the relative speed between the upper stool 6 and the carrier 4 that produces the work of polishing the work depends on the distance from the rotation axis of the upper stool 6 and the carrier 4. A steady difference will result. That is, in the vicinity of the rotation axis of the upper platen 6 and the carrier 4, the relative speed between the upper platen 6 and the carrier 4 is small, and the polishing action acting on the work is small. The relative speed between the upper stool 6 and the carrier 4 that produces the work of polishing the work is large.
[0007]
For this reason, in the conventional double-side polishing apparatus shown in FIG. 5, the polishing may be uneven on the upper surface of the work, and it may not be possible to obtain sufficient polishing accuracy.
Therefore, an object of the present invention is to improve the polishing accuracy in a polishing apparatus for polishing a work by rotating an upper platen that revolves with a carrier.
[0008]
[Means for Solving the Problems]
In order to achieve the object, the present invention provides a polishing object held by the carrier while rotating a predetermined number of carriers using a coaxially arranged sun gear and internal gear while revolving around the sun gear. A polishing apparatus for polishing the upper and lower surfaces of the carrier with a lower stool and an upper stool. Revolving means for revolving around the same axis as the rotation axis of the sun gear at the rotation speed as a rotation axis, and rotation means for rotating the upper platen with an axis parallel to the rotation axis of the carrier as the rotation axis. A polishing apparatus is provided, wherein the rotation axis of each upper platen is displaced in a direction perpendicular to the rotation axis of the corresponding carrier.
[0009]
Here, in such a polishing apparatus, the thickness of the carrier in the vertical direction is greater at the outer peripheral end than at the inside thereof, and the object to be polished is moved inside the outer edge of the carrier. A hole for restraining the carrier in the horizontal direction, and the upper platen is revolved with the carrier and the upper platen in a state where a lower end portion thereof is arranged inside the outer edge portion of the carrier. In the rotation operation, the carrier may have a size and a shape that do not interfere with the outer edge of the carrier.
[0010]
According to such a polishing apparatus, the rotation axis of each of the upper stools is displaced in a direction perpendicular to the rotation axis of the corresponding carrier with respect to the rotation axis of the corresponding carrier. The distance from the rotation axis of the upper surface plate to each of the above positions varies during polishing. By appropriately setting the amount of displacement, it is possible to eliminate the occurrence of a position on the work that can be subjected to only a weak polishing action by being constantly located near the rotation axis of the upper platen. Therefore, the unevenness of the polishing action is alleviated, and the polishing accuracy is improved.
[0011]
Further, in order to achieve the above object, the present invention uses a sun gear and an internal gear that are coaxially arranged to rotate a predetermined number of carriers around the sun gear while revolving around the sun gear, and to cover the carrier held by the carrier. Polishing the upper and lower surfaces of the polishing body by a lower surface plate and an upper surface plate that rotates around an axis parallel to the rotation axis of each carrier while revolving around the same axis as the rotation axis of the sun gear. A polishing method using an apparatus, wherein the carrier and the upper platen are arranged such that the rotation axis of each upper platen is displaced with respect to the rotation axis of the corresponding carrier; and The upper platen is rotated while revolving at the same rotation speed as the rotation speed of the carrier, while driving the internal teeth and causing the carrier to perform the revolving and rotation, thereby rotating the upper surface of the object to be polished. Polishing the lower surface; To provide a polishing method characterized by having.
[0012]
According to such a polishing method, the rotation axis of each upper platen is displaced in a direction perpendicular to the rotation axis of the corresponding carrier, so that the upper surface of the work held by the carrier is The distance from the rotation axis of the upper surface plate to each of the above positions varies during polishing. By appropriately setting the amount of displacement, it is possible to eliminate the occurrence of a position on the work that can be subjected to only a weak polishing action by being constantly located near the rotation axis of the upper platen. Therefore, the unevenness of the polishing action is alleviated, and the polishing accuracy is improved.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
FIG. 1 schematically shows the structure of the polishing apparatus according to the present embodiment.
In the figure, 11 is a sun gear, 12 is an internal gear, 13 is a lower surface plate, and 100 is a carrier.
The sun gear 11 is connected to a cylindrical sun gear drive shaft 111, and rotates the tooth portion 112 below the sun gear drive shaft by the drive system 40, thereby rotating in the horizontal direction about the rotation axis AA. Further, the internal gear 12 is connected to a cylindrical internal gear drive shaft 121, and the tooth portion 122 below the internal gear drive shaft is rotated by the drive system 40, so that the internal gear 12 rotates in the horizontal direction about the rotation axis AA. . The lower platen 13 is connected to a cylindrical lower platen drive shaft 131, and the toothed portion 132 below the lower platen drive shaft is rotated by the drive system 40, whereby the lower platen 13 rotates in the horizontal direction about the rotation axis AA.
[0014]
Next, reference numeral 15 denotes a cylindrical upper sun gear drive shaft, which is rotated in the horizontal direction about the rotation axis AA by rotating the tooth portion 151 below the upper sun gear drive shaft by the drive system 40. Reference numeral 16 denotes an upper internal gear drive shaft, which rotates in a horizontal direction about a rotation axis AA by rotating a tooth portion 161 below the upper internal gear drive shaft by the drive system 40.
[0015]
Here, in such a configuration, as shown in FIG. 2 a, the arrangement viewed from the vertical direction, each carrier 100 is formed by the teeth provided on the outer periphery thereof with the teeth provided on the outer periphery of the sun gear 11. It meshes with a row of teeth provided on the inner periphery of the gear 12. Then, as the sun gear 11 and the internal gear 12 rotate, each carrier 100 revolves around the rotation axis AA in FIG. 1 and the center of the carrier 100 as the rotation axis.
[0016]
Next, FIG. 2C shows the shape of the carrier 100.
In the figure, c1 represents the carrier 4 viewed from the vertical direction, c2 represents the carrier 4 viewed from the horizontal direction, and c3 represents the cross section of a vertical plane passing through the center of the carrier 100.
As shown in the figure, the carrier 4 is a circular sheet-shaped member having teeth arranged on the outer periphery, and has a hole 101 for holding a work. Here, the thickness of the carrier 100 is smaller than the target polishing thickness of the work so as not to interfere with the polishing of the work on the upper and lower work tables 35 and 13.
[0017]
Returning to FIG. 1, the base 20 rotatably supports the respective components by mechanisms such as hydraulic pressure and bearings. The base 20 supports the lower platen 13 by a hydrostatic bearing mechanism 19. The base 20 also supports a collecting frame 18 for collecting the abrasive, and the abrasive that has fallen from the lower platen 13 into the collecting frame 18 is discharged from a drain (not shown) provided in the collecting frame 18. You.
[0018]
Next, reference numeral 21 denotes a suspension arm unit, which supports the upper polishing unit 30 via a telescopic cylinder 22 such as a hydraulic pressure so as to be able to move up and down.
In the upper polishing unit 30, 31 is a frame fixedly connected to the lower part of the telescopic cylinder 22, 32 is a revolving plate attached to the frame 31 so as to be freely rotatable in a horizontal direction about a rotation axis AA, An upper internal gear 33 is supported on the frame 31 so as to be rotatable in the horizontal direction about the rotation axis AA. A reference numeral 34 is supported on the revolving disk 32 so as to be rotatable in the horizontal direction about the rotation axis AA. The upper sun gear 35 is supported by the revolving disk 32 via a telescopic cylinder 38 such as a hydraulic pressure so as to be able to rotate in the horizontal direction about the rotation axes BB and CC revolving around the rotation axis AA together with the revolving disk 32. An upper stool 36 is a driving force transmission gear supported on the frame 31 so as to be rotatable in the horizontal direction about the rotation axis AA, and 37 is a wheel that rotates on the frame 31 in the horizontal direction about the rotation axes DD and EE, respectively. Capable is supported drive gear.
[0019]
Here, in such a configuration, as shown in FIG. 2b, the arrangement seen from the vertical direction, each upper platen 35 is provided with a tooth row provided on the outer circumference thereof so that teeth provided on the outer circumference of the upper sun gear 34 are provided. The row meshes with a row of teeth provided on the inner periphery of the upper internal gear 33. The teeth provided on the inner periphery of the upper internal gear 33 mesh with the driving gear 37, and the driving gear 37 meshes with the driving force transmission gear 36.
[0020]
Returning to FIG. 1, when the upper polishing unit 30 is lowered to the position shown by the broken line in the figure by the extension 22 of the telescopic cylinder, the cylindrical meshing unit 341 provided at the center of the upper sun gear 34 becomes the upper sun gear drive shaft. 15 and rotates with the rotation of the upper sun gear drive shaft 15. The cylindrical meshing portion 361 provided at the center of the driving force transmission gear 36 meshes with the upper internal gear driving shaft 16, rotates with the upper internal gear driving shaft 16, and rotates via the driving gear 37. Rotate the upper internal gear.
[0021]
In addition, as shown in FIG. 2d, the distance between the rotation axis AA of the rotation axis of each upper platen 35 is the rotation axis of the rotation axis of each carrier 100, as shown in FIG. It corresponds to the distance from AA. The rotation axis of the upper platen 35 is shifted from the rotation axis of each carrier 100 by a predetermined distance in the circumferential direction of the revolution.
[0022]
Hereinafter, a polishing operation of a workpiece in such a polishing apparatus will be described.
Prior to the start of polishing, the operator moves each carrier 100 in the circumferential direction of the lower surface plate 3 from the rotation axis of the upper surface plate 35 in a state where the upper polishing portion 30 is separated upward from the lower surface plate 13. At a position shifted by a predetermined distance, the carrier 100 is placed on the lower platen 13 so that the teeth on the outer periphery mesh with the sun gear 11 and the internal gear 12, and a work is put into the hole 101 of each carrier 100.
[0023]
Next, the lower surface of each upper platen 35 abuts on the upper surface of the work, the meshing portion 361 of the driving force transmission gear 36 meshes with the upper internal gear drive shaft 16, and the meshing portion 341 of the upper sun gear 34 changes with the upper sun gear 34. The upper polishing unit 30 is lowered so as to mesh with the gear drive shaft 15.
Next, an internal gear drive shaft 121, a sun gear drive shaft 111, a lower platen drive shaft 131, and an upper internal gear are driven by the drive system 40 while the abrasive is supplied to the work position by an abrasive supply mechanism (not shown). The drive shaft 16 and the upper sun gear drive shaft 15 are rotated. At this time, the rotation speed of the internal gear drive shaft 121, the sun gear drive shaft 111, the upper internal gear drive shaft 16, and the upper sun gear drive shaft 15 is the revolving speed of the carrier 100 and the upper platen 35 around the rotation axis AA. Are set so that the rotation speeds of the carrier 100 and the upper surface plate 35 are different from each other. Further, the rotation speed of the lower stool 35 and the revolution speed of the carrier 100 are set to be different from each other.
[0024]
As a result, the upper and lower surfaces of the work held by the carrier 100 are polished by the lower surface plate 13 and the upper surface plate 35 while rotating around the center of the carrier 100 while revolving around the rotation axis AA.
The embodiments of the present invention have been described above.
By the way, in the above embodiment, a carrier having the same shape as the conventional carrier shown in FIG. 5 can be used as the carrier.
That is, in the polishing apparatus described above, as shown in FIG. 3, the carrier 100 is replaced with a carrier 200 having the shape shown in FIG. 4A. In FIG. 4a, 1 is a top view of the carrier, a2 is a side view, and a3 is a cross-sectional view of a vertical plane passing through the center of the carrier. As shown in the drawing, each carrier 100 has a shape in which the height of the outer edge portion 210 is higher than that of the work holding portion 220 inside the outer edge portion 210 in order to increase the strength. The work holding part 220 is provided with a through hole 201 for holding the work in the horizontal direction, and the height of the work holding part 42 is smaller than the target polishing thickness of the work. Further, the carrier outer edge portion 41 has a cylindrical shape having a just thickness, and a tooth row is provided on an outer periphery thereof.
[0025]
In order to use such a carrier 200, as shown in FIG. 3, in place of the upper stool 35, the diameter of the lower portion of the carrier 200 at least in the vertical length portion is equal to or greater than the height of the carrier 200. An upper surface plate 351 having a shape smaller than the diameter of the carrier 200 is used.
[0026]
Then, as shown in FIG. 4B, the position of the axis of rotation of the upper platen 351 is such that the lower part of each upper platen 351 is positioned at the outer edge 210 of each carrier 200 on the lower platen 13 when the upper polishing unit 30 is lowered. The carrier 200 is inserted at a position where the lower surface of the upper platen 351 is in contact with the upper surface of the work and is displaced from the axis of rotation of each carrier 100 by a predetermined distance in the circumferential direction of revolution. And the relative position of the upper stool 351.
[0027]
As described above, according to the polishing apparatus according to the present embodiment, the rotation axis of each of the upper stools 35/351 is displaced in the direction perpendicular to the rotation axis of the corresponding carrier 100/200. Therefore, the distance from the rotation axis of the upper platen 35/351 at each position on the upper surface of the work held by the carriers 100/200 varies during polishing. By appropriately setting the amount of displacement, it is possible to eliminate the occurrence of a position on the work that can be subjected to only a weak polishing action by being constantly located near the rotation axis of the upper platen. Therefore, the unevenness of the polishing action is reduced. In addition, the direction of the relative velocity between each position on the workpiece held by the carriers 100/200 and the lower surface of the upper platen 35/351 contacting the position, that is, the direction of the polishing action fluctuates in a complicated manner. Therefore, it is possible to correct polishing anisotropy that occurs depending on the direction of the polishing action. Therefore, according to the present embodiment, the polishing accuracy can be improved.
[0028]
The polishing apparatus shown in the present embodiment is a polishing apparatus for performing double-side polishing similar to the conventional one by using the rotation axis of the upper platen 35/351 and the rotation axis of the carrier 100/200 in alignment. Can also be used. Further, by polishing the work while protecting the upper or lower surface of the work with an appropriate protective material, the work can also be used as a single-side polishing apparatus.
[0029]
The polishing technique described above can be applied not only to a double-sided lapping machine and a double-side polishing machine but also to an apparatus for polishing one side.
The work to be polished by the polishing apparatus includes, for example, quartz, a semiconductor substrate, an optical member, and the like.
[0030]
【The invention's effect】
As described above, according to the present invention, the polishing accuracy can be improved in a polishing apparatus for polishing a work by rotating an upper platen that revolves with a carrier.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing a structure of a polishing apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram showing an arrangement of a carrier and an upper surface plate and a shape of the carrier in the polishing apparatus according to the embodiment of the present invention.
FIG. 3 is a view schematically showing another example of the structure of the polishing apparatus according to the embodiment of the present invention.
FIG. 4 is a diagram showing another example of the arrangement of the carrier and the upper platen and the shape of the carrier in the polishing apparatus according to the embodiment of the present invention.
FIG. 5 is a view schematically showing a structure of a conventional polishing apparatus.
[Explanation of symbols]
11: sun gear, 12: internal gear, 13: lower surface plate, 15: upper sun gear drive shaft, 16: upper internal gear drive shaft, 19: hydrostatic bearing mechanism, 20: base, 21: suspension arm section , 30: upper polishing part, 31: frame, 32: revolving disk, 33: upper internal gear, 34: upper sun gear, 35: upper surface plate, 36: driving force transmission gear, 37: driving gear, 40: driving System, 100: Carrier, 111: Sun gear drive shaft, 120: Work holder, 121: Internal gear drive shaft lower platen drive shaft, 200: Carrier, 210: Outer edge, 220: Work holder.

Claims (3)

A predetermined number of carriers are revolved around the sun gear while revolving around the sun gear using a coaxially arranged sun gear and internal gear, and the upper and lower surfaces of the object to be polished held by the carrier are formed by a lower surface plate and an upper surface plate. A polishing apparatus for polishing,
A plurality of upper stools provided for each carrier,
Revolving means for revolving each of the upper stools, with the same rotation axis as the rotation axis of the sun gear at the same rotation speed as the rotation speed of the carrier,
Each upper platen has a rotation unit that rotates on an axis parallel to the rotation axis of each carrier as a rotation axis,
A polishing apparatus, wherein a rotation axis of each of the upper stools is displaced relative to a rotation axis of a corresponding carrier in a direction perpendicular to the rotation axis. The polishing apparatus according to claim 1,
The outer peripheral end of the carrier has a greater vertical thickness than its inner side,
Inside the outer edge portion of the carrier, a hole for restricting movement of the object to be polished in the horizontal direction is provided,
The upper platen has a size that does not interfere with the outer edge portion of the carrier in the revolving and rotating operations of the carrier and the upper platen in a state where the lower end portion is disposed inside the outer edge portion of the carrier. A polishing apparatus having a shape. A predetermined number of carriers are revolved around the sun gear while revolving around the sun gear using a coaxially arranged sun gear and an internal gear, and the upper and lower surfaces of the object to be polished held by the carrier, a lower surface plate, and the carrier A polishing apparatus is provided which is polished by an upper platen that revolves around an axis parallel to the rotation axis of each carrier while revolving around the same axis as the rotation axis of the sun gear. The method,
A step of arranging the upper surface plate provided for each carrier and the carrier so that the rotation axis of each upper surface plate is displaced with respect to the rotation axis of the corresponding carrier.
While driving the sun gear and the internal gear teeth to cause the carrier to perform the revolution and rotation, the upper platen is rotated while rotating at the same rotation speed as the rotation speed of the carrier, and the polishing is performed. Polishing the upper and lower surfaces of the body.

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