JP2003094325A - Single-face polishing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a position error of a chuck mechanism in a single-face polishing device and to suppress erroneous absorption, lowering of the precision, or erroneous chuck by the prevention of the position error. SOLUTION: An index head 2 and a frame 12 are provided with paired lock devices 4. A lock pin 43 is advanced by an air cylinder to be fitted in a pin hole in a pin receiver body 42 so that the index head 2 substantially becomes a center impeller type and improves the rigidity. This constitution can prevent or suppress the propagation of the vibration and the displacement of the chuck shaft 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the technical field of a single-sided polishing apparatus, particularly a single-sided polishing apparatus suitable for polishing the surface of a semiconductor wafer.

[0002]

2. Description of the Related Art An index head for rotatably supporting a plurality of downward chucking mechanisms is disposed above a plurality of polishing disks, and the chucking mechanism holds a wafer and polishes the held wafer. There is known a device that presses against a polishing platen of a plate and mutually rotates the polishing platen and a chuck mechanism to perform polishing. As an example of such a single-side polishing apparatus, there is JP-A-2000-94317.

[0003]

In the above-mentioned single-side polishing apparatus, the wafer held by the chuck mechanism is polished in one polishing machine, the index head is indexed, and the index head is further indexed in the next polishing machine. Polishing with high polishing roughness is performed. The chuck mechanism grips a new wafer on the wafer supply / discharge table, sequentially moves a plurality of polishing discs while gripping the wafer, and places the last polished wafer on the wafer supply / discharge table. Therefore, when the chuck mechanism grips a new wafer and when the polished wafer is placed on the wafer supply / discharge table, another chuck mechanism performs polishing work. Vibrations and flexural displacements that occur when the chuck mechanism during the polishing operation receives a reaction force from the polishing plate of the polishing plate are transmitted to the chuck mechanism on the supply / discharge table via the index head. Due to such vibration and displacement, an error occurs in the position of the chuck mechanism on the supply / discharge table.

The position error of the chuck mechanism is a chucking error at the time of chucking a wafer by the chucking mechanism, thus lowering the accuracy of polishing work on each polishing plate, or a chucking error when the transfer robot picks up a wafer from the supply / discharge table. Cause of.

The present invention prevents the occurrence of a position error of the chuck mechanism in such a single-side polishing apparatus, and by preventing this error, the occurrence of a suction error, a decrease in accuracy, or a chuck error is suppressed. Is an issue.

[0006]

The above problems can be solved by the following means. That is, the solution means of the first aspect of the invention is to provide a base, a frame body provided on the base, an index head provided on the base and capable of indexing at a plurality of positions, and indexing of the index head. A chuck shaft having the center at an equal distance from the center of the index head, the chuck shaft being provided in the index head in the same number as the index number, the chuck shaft being capable of rotating and moving up and down while holding a work; And a chuck shaft feed drive device for moving the chuck shaft up and down, a chuck shaft rotation drive device provided for the index head and rotating the chuck shaft, and indexed by the index head. A plurality of polishing discs provided on the base below the chuck shaft, and provided on each of the polishing discs. A rotary surface-driven polishing platen, a supply / discharge table provided on the base below the chuck shaft indexed by the index head, and provided on the frame body and the index head, respectively. And a pair of locking devices for locking the index head at the indexing position of the index head.

A second aspect of the invention is to solve the problems by providing a base, a frame body provided on the base, an index head provided on the base and capable of indexing at a plurality of positions, and an index head for the index head. A chuck shaft that has its center at an equal distance from the indexing center and is provided on this index head in the same number as the indexing number, and that is capable of rotating and moving up and down while holding a workpiece, A chuck shaft feed drive device provided on the head for vertically moving the chuck shaft, a chuck shaft rotation drive device provided on the index head for rotating the chuck shaft, and indexed by the index head. A plurality of polishing discs provided on the base below the chuck shaft and on each of the polishing discs. Te, a polishing platen which is rotated,
Below the chuck shaft indexed by the index head, provided on one of the supply / discharge table provided on the base, the frame body and the index head, and at the indexing position of the index head. A single-side polishing apparatus comprising: a lock pin that can be moved in and out to lock the index head; and a lock device that includes a pin receiver provided on the other side to receive the lock pin.

A third aspect of the present invention is the single-side polishing apparatus according to the first or second aspect of the invention, wherein the chuck shaft has a pair of suction chucks for holding a plate-like work by vacuum suction. A single-sided polishing device comprising a device for holding two workpieces by the chuck device and polishing by holding the surface on the opposite side of the held work against the polishing platen. is there.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a partial top view showing an example of an embodiment of a single-side polishing machine according to the present invention. 2 and 3 are a sectional view taken along the line AA and a sectional view taken along the line BB in FIG. 1, respectively. The single-side polishing apparatus 1 is provided with a frame body 12 on a base 11 so as to form an entire framework of the apparatus, that is, a framework. Center column 13 almost in the center of the base 11.
Are mounted upright, and the upper part thereof is joined to the ceiling of the frame 12. The index head 2 is rotatably supported in the middle of the center column 13 via a bearing 221, and a drive source (not shown) enables index (indexing) rotation by a predetermined angle. In addition, in this example, it is possible to index and rotate by 120 degrees.

The index head 2 has a plurality (three) equal to the index number at the same distance from the center.
Bearing box 213 is provided. In the bearing box 213,
A hollow shaft 214 is rotatably supported, and the chuck shaft 21 is fitted in the hollow portion of the hollow shaft 214. The chuck shaft 21 and the hollow shaft 214 are spline-connected or key-connected, and the hollow shaft 214 and the chuck shaft 21 are rotationally connected, but they are mutually movable in the axial direction. Further, a pulley 215 is coaxially provided on the hollow shaft 214, and the pulley 218 and the belt 216 are provided.
The rotation of the electric motor 217 is transmitted via the. Electric motor 21
The chuck shaft rotation drive device 212 is composed of the pulley 7, the pulley 218, the belt 216, and the pulley 215. Further, the hollow shaft 214 (hence, the chuck shaft 21) is placed by a control device (not shown) in order to place the work W at a predetermined position on a supply / discharge table 61 described later or to suck and hold the work W from this table. It can be stopped at a predetermined angular position.

At the upper shaft end of the chuck shaft 21, a chuck shaft feed driving device 21 composed of a piston cylinder mechanism or the like.
1 is provided so that the chuck shaft 21 can be driven in the axial direction, that is, the vertical direction. The chuck shaft 21 has a work holder 219 at its lower end, and can hold a work (wafer) W by a suction force from a vacuum suction device (not shown). In this example, two works W can be held by one work holder 219.

A pin receiver 42 constituting the lock device 4 is fixed near the outer circumference of the index head 2.
The lock device 4 will be described later.

On the base 11, a plurality of (in this example, 2
Polishing plate 3 is arranged. The arrangement position is a position below the chuck shaft 21 in each index of the index head 2. The polishing platen 3 includes a polishing platen 31 having a flat upper surface and capable of being rotationally driven. Polishing surface plate 3
The upper surface of 1 serves as a polishing surface. Slurry (a suspension of loose abrasive grains) is supplied to the polishing surface, and further pressing force and relative motion are applied between the work W and the polishing surface to perform a polishing action. Is to give.

In this example, the supply / discharge table 61 is provided with four positions (workpiece mounting positions) on which the work W can be placed, and two positions as shown in FIG. 1 are provided by a feeding means (not shown). It can take a and b. The work W is supplied and discharged in units of two sheets. Here, the operation of the single-side polishing apparatus except for the lock device 4 will be described.

The supply / discharge table 6 is located at the position a indicated by the solid line in FIG.
When there is 1, the unpolished work W is placed at each of the two lower positions in FIG. At this time, nothing is placed on the upper two positions (first state). The two workpieces W that have been polished by the two polishing disks 3 come to above the above-mentioned workpiece mounting position on which nothing is placed by the indexing of the index head 2. The chuck shaft 21 descends, and the two workpieces W that have been polished are placed on this. At this time, the chuck shaft 21 is stopped at a predetermined angular position so that the two works come to that position. After the chuck shaft 21 is lifted, the supply / discharge table 61 is then moved to the upper side in FIG.
When moved to the
A piece of work W comes. Here, the chuck shaft 21 descends again and sucks and holds the unpolished work W. The chuck shaft 21 holding the unpolished work W is the index head 2
By the indexing to reach the upper part of the polishing platen 3, the work W is pushed down toward the polishing platen 31. The rotation of the chuck shaft 21 is also started, whereby the first polishing of the unpolished work W is started.

During this polishing, the supply / discharge table 61 located at the position b is moved to the position a. At this position a, the workpiece W that has finished polishing through the two polishing disks comes below another chuck shaft 21, but this time, the transfer robot 5
Picks up this work W, rotates it, and stores it in the empty slot of the polished cassette 52. Next, the supply / discharge table 61 moves to the position b, and the transfer robot 5 places the two works W taken out from the unpolished cassette 51 at the two positions below the supply / discharge table 61. That is, since the unground work W is placed at the two work placement positions on the lower side of the supply / discharge table 61 and the two work placement positions on the upper side are empty, the state returns to the initial state. In this way, the work in the unpolished cassette 51 becomes
After that, it is polished and stored in the polished cassette 52.

As described above, while the two polishing disks 3 are being polished, the chuck shaft 21 holds the workpiece on the supply / discharge table 61.
The chuck shaft 21 receives a reaction force from the polishing plate 3 and is vibrated and flexibly displaced. The index head 2 also vibrates or displaces due to this vibration or flexural displacement, and is transmitted to the chuck shaft 21 on the supply / discharge table 61 via this. Due to such vibration and displacement, an error occurs in the position of the chuck shaft 21 on the supply / discharge table 61. On the contrary, vibrations and displacements that occur when the work W is gripped or placed are transmitted to the polishing site in the opposite course. Therefore, the position error of the chuck shaft 21 is caused by a suction error at the time of gripping (sucking) the work, thus lowering the accuracy of the polishing work on each polishing plate, or when the transfer robot 5 picks up the work W from the supply / discharge table 61. It may cause a chuck error. Since these vibrations and displacements are transmitted to each other via the index head 2, the present invention prevents or suppresses this by increasing the rigidity of the index head 2.

For this reason, the one-side polishing apparatus 1 of the present invention is provided with the lock device 4. The lock device 4 is composed of a set of a lock pin unit 41 having a drive device and a pin receiver 42. The lock device 4 is arranged at a plurality of positions, one near the chuck shaft 21 of the index head 2 and the other at a position facing the frame shaft.

The lock pin unit 41 and the pin receiving body 42 are fixed to one side and the other side of the frame body 12 firmly fixed to the index head 2 and the base 11. A lock pin 43 having a taper is housed in the lock pin unit 41 so as to be able to move forward and backward by a drive device, for example, a fluid cylinder, and by moving forward, the lock pin 43 fits into a pin hole of a pin receiving body 42 facing each other. When the lock pin 43 is fitted, the index head 2 having a cantilever structure has a substantially double-support structure, and the rigidity is increased step by step. Therefore, the vibrations and displacements described above are not caused by the lock device 4.
Is firmly received by and is prevented or suppressed from propagating to other places.

Thus, a suction error when gripping (sucking) the work, and thus the accuracy of the polishing work on each polishing plate is reduced.
Alternatively, a chuck error or the like when the transfer robot 5 picks up the work W from the supply / discharge table 61 is prevented or suppressed. In addition, it is preferable that the indexing direction (rotational direction) of the index head 2 is not constant but opposite in a proper cycle. If the direction is constant, the cable for sending the driving power (electrical or fluid pressure) to the index head 2 is twisted by the indexing rotation, so a means for allowing continuous rotation is required. This is not necessary if the above is reversed in an appropriate cycle.

[0021]

As described above, when the single-side polishing apparatus of the present invention is used, the chucking mechanism causes a suction error when a wafer is sucked, which reduces the accuracy of the polishing work on each polishing plate, or the transfer robot supplies and discharges. This has the effect of preventing or suppressing chucking errors when picking up a wafer from the table.

[Brief description of drawings]

FIG. 1 is a partial top view showing an example of an embodiment of a single-side polishing apparatus according to the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a sectional view taken along line BB in FIG.

[Explanation of symbols]

1 Single-side polishing machine 2 index head 3 polishing machine 4 Lock device 5 Transport robot 11 bases 12 frame 13 Center column 21 chuck axis 31 polishing surface plate 41 Lock pin unit 42 pin receptacle 43 Lock Pin 51 unpolished cassette 52 Polished cassette 61 Supply and discharge table 211 Chuck shaft feed drive device 212 Chuck shaft rotation drive device 213 bearing box 214 hollow shaft 215, 218 pulley 216 belt 217 electric motor 219 Work holder 221 bearing W work

Claims (3)

[Claims] 1. A base, a frame provided on the base, an index head provided on the base and capable of indexing at a plurality of positions, and an index head at an equal distance from the indexing center of the index head. A chuck shaft that has a center and is provided in the index head in the same number as the number of indexes, the chuck shaft being capable of rotating and moving up and down while holding a work, and the chuck shaft provided in the index head. A chuck shaft feed drive device for moving the chuck shaft up and down, a chuck shaft rotation drive device provided on the index head for rotating the chuck shaft, and below the chuck shaft indexed by the index head. A plurality of polishing discs provided on the base, and polishing drives provided on each of the polishing discs and driven to rotate. The surface plate, the supply / discharge table provided on the base below the chuck shaft indexed by the index head, the frame body and the index head, respectively, and the index head indexed. In position,
And a pair of locking devices for locking the index head. 2. A base, a frame body provided on the base, an index head provided on the base and capable of indexing at a plurality of positions, and an index head at an equal distance from the indexing center of the index head. A chuck shaft that has a center and is provided in the index head in the same number as the number of indexes, the chuck shaft being capable of rotating and moving up and down while holding a work, and the chuck shaft provided in the index head. A chuck shaft feed drive device for moving the chuck shaft up and down, a chuck shaft rotation drive device provided on the index head for rotating the chuck shaft, and below the chuck shaft indexed by the index head. A plurality of polishing discs provided on the base, and polishing drives provided on each of the polishing discs and driven to rotate. The surface plate, the supply / discharge table provided on the base below the chuck shaft indexed by the index head, and one of the frame body and the index head, the index head At the indexing position of
A single-side polishing machine comprising: a lock device that can be moved in and out to lock the index head; and a lock device that includes a pin receiving body that is provided on the other side to receive the lock pin. 3. The single-side polishing apparatus according to claim 1 or 2, wherein the chuck shaft is provided with a pair of suction chuck devices for holding a plate-shaped work by vacuum suction. A single-sided polishing device, which holds two works by a chucking device and presses the surface on the opposite side of the held work against the polishing platen to perform polishing.