JP3172313B2 - Method and apparatus for repairing surface plate in flat surface polishing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for correcting flatness of upper and lower platens in a planar polishing apparatus for polishing both surfaces of a work such as a semiconductor wafer or a magnetic disk substrate. .

[0002]

2. Description of the Related Art A carrier holding a work is meshed with a sun gear and an internal gear, and while the carrier is in planetary motion by both gears, the work held by the carrier is sandwiched between upper and lower platens from both sides for polishing. A flat surface polishing apparatus is known.

In such a surface polishing apparatus, the surface plate is worn by the processing, and the flatness thereof is reduced, thereby lowering the processing accuracy of the work. Therefore, the flatness of the surface plate is constantly controlled, and the surface flatness is corrected as necessary. Need to be done, so
Conventionally, various correction methods have been proposed.

For example, Japanese Unexamined Patent Publication No. 60-16363 discloses a technique in which a plurality of small correction carriers having the same size as the above-mentioned work holding carrier are used, and these correction carriers are combined with a sun gear, an internal gear, and the like. The upper and lower platens are corrected by meshing them with planetary motion with both gears.However, since each correction carrier is small and independent, the corrected platen surface There is a drawback that undulation is easily generated and correction accuracy is not good.

On the other hand, Japanese Utility Model Laid-Open Publication No. Sho 64-50048 uses a single correction intermediate surface plate having a large diameter slightly smaller than the surface plate, and the intermediate surface plate is eccentrically oscillated and rotated. It is disclosed that the entire surface is rubbed with the surface plate. According to this, compared to the above-described conventional example using a plurality of small-sized correction carriers, undulation is less likely to occur on the surface of the surface plate, so that the correction accuracy is high. There is an advantage.

However, the correction intermediate platen is a support member that rotates while maintaining concentricity with the sun gear, a pair of upper and lower correction intermediate platen members that are swingably supported by the support member,
An eccentric drive gear for eccentrically oscillatingly rotating the intermediate platen body by meshing with a sun gear and an internal gear to perform planetary motion;
It consists of a large number of members such as a support shaft that regulates the movement between the support member and the intermediate platen main body, an eccentric drive gear and a bearing that supports the rotating part of the support shaft, and therefore the structure is very complicated, The production and handling are troublesome and the price is high. There is a problem that the eccentric oscillating rotation of the intermediate platen becomes unstable due to the wear of the bearing, and the polishing accuracy is reduced.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and an apparatus for correcting a surface plate in a simple and highly accurate manner.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a correction method according to the present invention comprises a sun gear and an internal gear, which mesh with a carrier holding a work to planetary move the carrier, and the carrier held by the carrier. A flat surface polishing machine having an annular upper and lower platen for holding a workpiece from both sides, wherein the internal gear has an outer diameter smaller than the outer diameter of the platen and an inner diameter larger than the inner diameter of the platen. And the small diameter correction carrier is meshed between the sun gear and the large diameter correction carrier in the inner hole of the large diameter correction carrier, and the small diameter correction carrier is moved between the upper and lower platens in a planetary motion. And the large-diameter correction carrier is eccentrically oscillated and rotated.

In addition, the correction device of the present invention is a sun gear and an internal gear that mesh with a carrier holding a work to planetary move the carrier, and an annular ring that grinds the work held by the carrier from both sides. An apparatus for correcting the flatness of both surface plates of a surface polishing apparatus having upper and lower surface plates, wherein an outer diameter is smaller than an outer diameter of the surface plate and an inner diameter is larger than an inner diameter of the surface plate. And a large-diameter correction carrier having gears on the inner and outer circumferences and meshing with the internal gear with the outer circumference gears, and a disk-like shape with a gear on the outer circumference, and a sun-shaped carrier inside the inner hole of the large-diameter correction carrier. It comprises a gear and a small diameter correction carrier that meshes with a gear on the inner periphery of the large diameter correction carrier. An annular recess may be provided on the correction surface of the large diameter correction carrier.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIGS. 1 and 2 show a main part of a planar polishing apparatus in a state where the flatness of upper and lower stools 1 and 2 is corrected. A work (not shown) having the upper and lower bases 1 and 2 and a sun gear 3 and an internal gear 4 which are engaged with the sun gear 3 and the internal gear 4 to carry out planetary movement. (Not shown) is sandwiched between the upper and lower bases 1 and 2 and polished. When the upper and lower bases 1 and 2 are to be corrected, the carrier for holding the work is taken out and as shown in the figure. The large diameter correction carrier 5 and the small diameter correction carrier 6 are mounted.

The large-diameter correction carrier 5 has an annular shape whose outer diameter is smaller than the outer diameter of the platens 1 and 2 and whose inner diameter is larger than the inner diameter of the platens. Gears 5a and 5b are formed on the inner and outer circumferences of the ring, respectively, and the outer gear 5a meshes with the internal gear 4 so that the upper and lower bases 1 and 2 are fixed. It is arranged so that it may be located eccentric with respect to these surface plates. At this time, the gear 5 b on the inner periphery of the large diameter correction carrier 5 is not meshed with the sun gear 3. A plurality of holes 7 are formed in the large-diameter correction carrier 5, and these holes serve as clearance holes for abrasive grains during correction.

On the other hand, the small-diameter correction carrier 6 has a disk shape in which both front and rear surfaces are correction surfaces that come into contact with the upper and lower platens 1 and 2, and a gear 6a is provided on the outer periphery thereof. In the inner hole 5c of the carrier 5, the sun gear 3 and the large-diameter modified carrier 5 are formed on a line connecting the mesh point P between the large-diameter modified carrier 5 and the internal gear 4 and the center O of the sun gear 3. It is arranged so as to mesh with both the peripheral gear 5b. The small diameter correction carrier 6 can also be provided with a relief hole for abrasive grains.

When the sun gear 3 is rotated in the direction of arrow a at a desired speed in FIG. 2, the small-diameter correction carrier 6 revolves around the sun gear 3 in the direction of arrow c while rotating in the direction of arrow b. The large-diameter correction carrier 5 includes the internal gear 4
The eccentric movement by changing the meshing position with the internal gear 4 in the direction of the arrow d while moving the arrow e at a speed based on the difference in the number of teeth with the internal gear 4.
Rotate in the direction. As a result, the small-diameter correction carrier 6 rubs against the upper and lower platens 1 and 2 while performing planetary motion around the sun gear 3, and the large-diameter correction carrier 5 rotates eccentrically with respect to the sun gear 3. The flatness of the upper and lower bases 1 and 2 is corrected by completely sliding on the upper and lower bases 1 and 2.
In this case, the large and small correction carriers 5 and 6 having different sizes and motion trajectories are rubbed simultaneously with the surface plates 1 and 2 so that
The same effect as in the case where the three surfaces are rubbed is obtained, whereby it is possible to obtain a surface plate with little undulation and high flatness.

In the above description of the correcting operation, the case where only the sun gear 3 is rotated for easy understanding has been described as an example. However, the internal gear 4 may be rotated at the same time. The rotation direction and rotation speed of the internal gear 3 and the internal gear 4 need to be set within a range in which the correction carriers 5 and 6 can perform the correction operation. In addition, it is a matter of course that the upper and lower platens 1 and 2 may be rotated at the desired speed in the same direction or in opposite directions at the time of the above correction.

FIG. 3 shows an example of a different configuration of the large-diameter correction carrier 5. The large-diameter correction carrier 5 has an annular recess 8 provided on one correction surface.

Next, an experiment for correcting the surface plate according to the present invention will be described.
Will be explained. In the experiment, the device as shown in FIGS. 1 and 2 was used.
Use and supply GC2500 as abrasive grains
3-way rotation method for rotating the disk, sun gear and internal gear
It was performed by the formula. At this time, the rotation direction of the large-diameter correction carrier
May be in either direction, but here, the sun gear
By making the angular velocity greater than that of the internal gear,
The clockwise direction (forward rotation) was the same as when processing the work . So
Table 1 shows the results. On the other hand, to obtain a comparative example,
Repair the surface plate by the conventional method using a small diameter correction carrier.
Did positive. The rotation direction of the small-diameter correction carrier at this time
Makes the angular velocity of the sun gear smaller than that of the internal gear.
Counter-clockwise when machining the workpiece
(Reverse). Table 2 shows the results. In these tables
The flatness is minus when the surface plate is concave, and when plus it is convex.
It is in the state.

As can be seen from these results, the present invention
The flatness of the lower surface plate from +6 μm to 0 μm.
The correction time needed to correct is about 8 hours,
In the conventional method, the flatness of the lower platen is increased from +7 μm to +2 μm.
It takes about 18 hours to correct to m.
The invention requires less than 10 hours of correction time. In addition,
The above-mentioned modification of the surface plate is a 4-way rotation that also rotates the lower surface plate.
Can be performed by the reverse method, but here,
To reduce the runout of the board and improve the correction accuracy as much as possible
This was performed by a three-way rotation method in which the lower platen was fixed.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

As described above, according to the present invention, the flatness of the surface plate can be easily and accurately corrected by using only two types of correction carriers, large and small. In addition, since the two correction carriers are independent of each other and used by meshing with each other or with the sun gear and the internal gear, each member is provided with a bearing or the like as in a conventional correction intermediate platen. The structure is simpler than those connected, and there is no problem that the eccentric oscillating rotation becomes unstable due to the wear of the bearing, and the correcting operation can be stabilized.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing an embodiment of the present invention.

FIG. 2 is a plan view showing a state where an upper surface plate in FIG. 1 is removed.

FIG. 3 is a cross-sectional view showing another example of the structure of the large-diameter correction carrier.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Upper surface plate 2 Lower surface plate 3 Sun gear 4 Internal gear 5 Large diameter correction carrier 6 Small diameter correction carrier 5c Inner hole 8 Depression

Claims (3)

(57) [Claims] 1. A sun gear and an internal gear which mesh with a carrier holding a work to planetary move the carrier, and an annular upper and lower platen for polishing the work held by the carrier from both sides. In the above-mentioned flat surface polishing apparatus, an annular large-diameter correction carrier having an outer diameter smaller than the outer diameter of the platen and an inner diameter larger than the inner diameter of the platen is meshed with the internal gear, and the large-diameter correction carrier is The small-diameter correction carrier is meshed between the sun gear and the large-diameter correction carrier in the inner hole, the small-diameter correction carrier is planetary-moved between the upper and lower platens, and the large-diameter correction carrier is eccentrically rotated to rotate. A method of correcting a surface plate in a plane polishing apparatus, wherein the surface degree of the surface plate is corrected. 2. A sun gear and an internal gear which mesh with a carrier holding a work to planetarily move the carrier, and an annular upper and lower platen for polishing the work held by the carrier from both sides. An apparatus for correcting the flatness of both of the surface plates of the surface polishing device provided, wherein the outer diameter is smaller than the outer diameter of the surface plate and the inner diameter is larger than the inner diameter of the surface plate, and the inner and outer surfaces are formed. A large-diameter correction carrier that is provided with a gear on each circumference and meshes with the internal gear with an outer peripheral gear; and a disc-shaped disk with a gear on the outer circumference, and a sun gear and the large diameter in an inner hole of the large-diameter correction carrier. A small-diameter correction carrier meshed with a gear on the inner periphery of the correction carrier. 3. The correction device according to claim 2, wherein an annular recess is provided on a correction surface of the large-diameter correction carrier.