JP5614723B2 - Polishing apparatus and polishing method for workpiece - Google Patents

Description

  The present invention relates to a polishing apparatus.

  For glass plates for FPD (Flat Panel Display) such as liquid crystal displays and plasma displays, and glass plates for semiconductor applications, a glass ribbon formed into a strip shape by a glass ribbon molding device is converted into a glass plate of a predetermined rectangular size. By cutting and folding, a glass plate having a predetermined outer dimension is manufactured. Further, a glass plate for a wafer is manufactured into a glass plate having a predetermined outer dimension by cutting a silicon single crystal rod (ingot) with a cutting device. And these glass plates are conveyed to a grinding | polishing process through a washing | cleaning process and an inspection process. And the fine unevenness | corrugation and waviness of the surface (polishing surface) of a glass plate are grind | polished by a grinding | polishing apparatus at a grinding | polishing process, and it manufactures to the glass plate which satisfied the flatness requested | required of a product substrate.

  Patent Document 1 discloses a continuous polishing apparatus that polishes a polishing surface of a glass plate with a number of polishing pads while the glass plate is continuously conveyed by a feed table. Each polishing pad is pressed against the polishing surface of the glass plate and swings in a direction perpendicular to the conveying direction of the glass plate. The rotation phase is reversed.

  On the other hand, the polishing apparatus of Patent Document 2 supplies slurry (polishing liquid) to a polishing surface plate, and exudes this slurry from the surface of the polishing pad to polish the glass plate. Further, the grooved polishing pad disclosed in Patent Document 2 has a plurality of grooves having a width of 2 to 6 mm and a depth of 1 to 5 mm formed on the surface thereof along one direction at a pitch of 5 to 10 mm. Yes. According to this polishing pad, the polishing rate is improved by the polishing action of the groove, and the slurry used for polishing can be discharged to the outside of the polishing pad through the groove, so that the polishing pad is clogged. It is difficult to occur, and there is an advantage that the polishing power is stabilized.

JP-A-6-246623 JP 2004-122351 A

  However, when the grooved polishing pad of Patent Document 2 is used as the polishing pad of Patent Document 1, the groove of the polishing pad is transferred to the polishing surface of the glass plate, and a streak-like polishing mark is generated on the polishing surface. there were. For this reason, there is a problem that it is difficult to polish the polished surface of the glass plate with high flatness.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a polishing apparatus capable of alleviating polishing marks generated by transferring a groove of a polishing pad to a polishing surface of an object to be polished. And

In order to achieve the above object, the present invention relates to the object to be polished by relatively pressing the object to be polished and a polishing pad having a plurality of grooves in contact with the polishing surface of the object to be polished. A polishing apparatus that polishes the polishing surface of the plurality of grooves , wherein the plurality of grooves are parallel, hold a non-polishing surface of the object to be polished and rotate the object to be polished around a predetermined axis; A polishing apparatus comprising: an operation means for revolving the center of mass of the polishing pad or revolving while revolving around a revolving axis eccentric with respect to the center of gravity of the polishing pad .
An object to be polished is provided by polishing an object to be polished using the polishing apparatus of the present invention.

  When a stationary object is polished by a moving polishing pad as in a conventional polishing apparatus, the groove of the polishing pad regularly hits the polishing surface of the object to be polished, so that the polishing mark is generated. In the present invention, by rotating the object to be polished, the grooves of the polishing pad come into random contact with the polishing surface of the object to be polished, so that the polishing marks can be alleviated.

According to the present invention, the polishing pad is revolved, or by rotating while revolving, translating the polishing pad against the polishing surface of the object to be polished. By simply revolving the polishing pad, the groove of the polishing pad randomly hits the polishing surface of the workpiece. Will improve.

In the present invention, it is preferable that the rotation direction of the object to be polished by the rotation unit and the revolution direction of the polishing pad by the operation unit, or the revolution direction and the rotation direction are set in opposite directions.

Direction of revolution of the polishing pad and the rotational direction of the workpiece, or a polishing apparatus and rotation direction is set in the same direction, when comparing the polishing apparatus of the present invention, the polishing apparatus of the present invention, any of the polishing surface Since the relative speed of the polishing pad passing through one point becomes faster than that of the former polishing apparatus, the polishing efficiency can be improved and the polishing time can be shortened.

The present invention includes a conveying means for conveying the object to be polished in a predetermined direction together with the rotating means, and a plurality of the polishing pads are arranged with a predetermined interval in a conveying path of the object to be polished by the conveying means. is, preferably it to polish the surface of the workpiece during conveyance.

  The present invention applies a rotating means for rotating an object to be polished to a continuous polishing apparatus that polishes the polishing surface of an object to be polished by a number of polishing pads while the object to be polished is continuously conveyed by a feed table. It is.

  For a workpiece to be polished by a polishing apparatus that does not convey the workpiece, the throughput varies depending on the amount of polishing, which may reduce the production efficiency. According to the present invention, since the object to be polished is polished by the continuous polishing apparatus, the throughput does not change according to the polishing amount, and a reduction in production efficiency can be suppressed.

  The polishing pad of the present invention is preferably revolved with an adjacent polishing pad having a rotational phase difference.

  According to the present invention, since the load acting on the object to be polished can be offset by the rotational movement of each polishing pad, the object to be polished can be uniformly polished.

  The rotating means of the present invention preferably rotates the disk-shaped object to be polished around its mass center of gravity.

  When a rectangular object to be polished is applied to a continuous polishing apparatus, the object to be polished must be mounted on a feed table with a wide interval in order to prevent interference with adjacent objects to be polished. As a result, the number of objects to be polished mounted on the feed table is reduced, so that the production efficiency is lowered. On the other hand, a rotating means that is a disk-shaped object to be rotated around the center of mass of the object to be polished does not need to increase the interval in order to prevent interference. As a result, the number of objects to be polished mounted on the feed table is increased as compared with a rectangular object to be polished, so that the production efficiency is improved.

  According to the polishing apparatus of the present invention, the object to be polished is rotated and the polishing pad is moved in parallel with the polishing surface of the object to be polished. The generated polishing marks can be reduced.

Plan view of main part of polishing apparatus according to embodiment Side view of the polishing apparatus shown in FIG. Enlarged perspective view of the main part of the polishing pad The top view which showed the rotation mechanism part of the turntable Plan view of an object to be polished showing an example of rotating the object to be polished around its center The top view of a to-be-polished object which shows the example which revolved the to-be-polished object by offsetting the center of one to-be-polished object with respect to the rotation center of a rotary table The top view of the to-be-polished object which shows the example which revolved the to-be-polished object by offsetting the center of 3 or 4 to-be-polished object with respect to the rotation center of a rotary table Explanatory drawing showing the shape of the workpiece mounted on the feed table

  Hereinafter, preferred embodiments of a polishing apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a plan view of an essential part of a polishing apparatus 10 according to an embodiment, and FIG. 2 is a side view thereof.

  The polishing apparatus 10 according to the embodiment includes a plurality of polishing pads 16 and 16 disposed above the feed table 14 while continuously transporting the disk-shaped workpiece 12 in the direction indicated by the arrow A by the feed table 14. This is a continuous polishing apparatus that polishes the polishing surface of the workpiece 12 by.

  1 and 2 show four polishing pads 16, 16,... In the case of a continuous polishing apparatus, several tens of polishing pads 16 are arranged in the transport direction indicated by an arrow A. Are arranged along. Further, the polishing apparatus of the present invention is not limited to the continuous polishing apparatus 10 and can be applied to a single wafer polishing apparatus that does not convey a glass plate.

  As shown in FIG. 2, the polishing apparatus 10 has rails 18 laid along the conveying direction, and the feed table 14 is placed on the rails 18 so as to be able to run. The non-polished surface of the workpiece 12 is adsorbed and held on the suction sheet 20 disposed on the upper surface of the feed table 14 so as to be detachable. A rack 22 parallel to the rail 18 is provided on the lower surface of the feed table 14, and a pinion (conveying means) 24 is engaged with the rack 22. The pinion 24 is rotatably attached to the rail 18 side, and the rotation shaft 25 of the pinion 24 is connected to the rotation shaft of a drive motor (not shown). Accordingly, when the pinion 24 is rotated in the clockwise direction in FIG. 2 by the driving force of the drive motor, the power is transmitted to the feed table 14 via the rack 22, and the feed table 14 is moved at a predetermined speed in the direction of arrow A. It is conveyed by. As a result, the object to be polished 12 and a rotating means to be described later for rotating the object to be polished 12 are conveyed together with the feed table 14 in the direction of arrow A.

  When the feed table 14 arrives at the end position of the rail 18, the workpiece 12 that has been polished at that position is peeled off from the suction sheet 20. Then, the feed table 14 is transferred to a starting end position of a roller conveyor (not shown) arranged in parallel with the rail 18, and an object to be polished next is attached to the suction sheet 20 during the return by the roller conveyor. Attached. Thereafter, the feed table 14 is transferred again from the end position of the roller conveyor to the start end position of the rail 18 and moved in the direction of arrow A.

  FIG. 3 is an enlarged perspective view of a main part of the polishing pad 16. The shape of the polishing pad 16 is a plate-like body. The material of the polishing pad 16 is not particularly limited, and examples thereof include polyurethane resin, urea resin, melamine resin, phenol resin, epoxy resin, unsaturated polyester resin, alkyd resin, and olefin resin. Further, the surface of the polishing pad 16 that comes into contact with the polishing surface of the workpiece 12 is provided with a plurality of grooves 17, 17... As shown in FIG. These grooves 17 are parallel to each other, and are attached to the lower surface of the polishing head 26 in FIG. 2 so as to be in a direction orthogonal to the moving direction A of the feed table 14 in FIG.

  As shown in FIG. 2, the polishing head 26 is connected to an output shaft of a known revolving motion mechanism (operation means) 28 such as a planetary gear mechanism. The revolution motion mechanism unit 28 is equipped with a drive motor (not shown), and the revolution motion mechanism unit 28 is driven by the drive motor, whereby the output shaft performs a revolution motion. As a result, the polishing pad 16 attached to the polishing head 26 is driven to revolve so that the mass center of gravity O point of the polishing pad 16 moves along the locus indicated by the arrow B around the revolution axis P point. By the revolution operation of the polishing pad 16, the polishing pad 16 is translated with respect to the polishing surface of the workpiece 12. In addition, if the revolution motion mechanism part 28 is comprised so that rotation may be given to the said output shaft of the revolution motion mechanism part 28, the polishing pad 16 can rotate, revolving along the locus | trajectory of the arrow B.

  On the other hand, the suction sheet 20 shown in FIG. 2 that holds the object to be polished 12 by suction is attached to the upper surface of the rotary table (rotating means) 30. The rotary table 30 is formed in a disk shape, and a rotary shaft 32 is connected to the center of the lower surface thereof.

  FIG. 4 is a plan view showing a rotation mechanism portion of the turntable 30. As shown in FIG. 4, the rotary shaft 32 is erected at the center of a disk 36 in which a gear 34 is engraved on the peripheral surface. The disk 36 is rotatably attached to the feed table 14, and a gear 38 is engaged with the gear 34. The gear 34 and the gear 38 form a bevel gear, and an output shaft of a motor (not shown) is connected to the shaft 40 of the gear 38. Therefore, when the motor is driven, the power is transmitted from the gear 38 to the disk 36 via the gear 34 and from the disk 36 to the rotary table 30 via the rotary shaft 32, so that the rotary table is transmitted. 30 rotates about the central axis Q. As a result, the workpiece 12 attracted and held by the suction sheet 20 rotates in the counterclockwise direction indicated by the arrow C about the central axis Q.

  Next, the operation of the polishing apparatus 10 according to the embodiment will be described.

Polishing apparatus 10 of the embodiment, while conveying the feed table 14 by a feed operation of the rack 22 and the pinion 24 in the direction of arrow A, the workpiece 12 together with revolving the polishing pad 16 (or revolution and rotation) thereof By rotating to the center, the polishing surface of the workpiece 12 is continuously polished by a number of polishing pads 16, 16.

  When a stationary object is polished by a revolving and / or rotating polishing pad as in a conventional polishing apparatus, the groove of the polishing pad regularly hits the polishing surface of the object. In other words, the polishing pad does not uniformly polish the entire polishing surface of the object to be polished, but is biased to a specific portion of the polishing surface. For this reason, in the conventional polishing apparatus, polishing marks are generated on the polishing surface of the object to be polished.

  On the other hand, since the polishing apparatus 10 according to the embodiment rotates the object to be polished 12, the groove 17 of the polishing pad 16 comes into contact with the polishing surface of the object 12 at random. Thereby, the polishing apparatus 10 according to the embodiment can relieve the polishing marks generated in the conventional polishing apparatus.

  In addition, the polishing apparatus 10 of the embodiment merely revolves the polishing pad 16 so that the groove 17 of the polishing pad 16 randomly hits the polishing surface of the workpiece 12, and if the revolution and rotation are combined, Since the contact is more random, the flatness of the polished surface of the workpiece 12 is improved.

In the above embodiment, as shown in FIG. 5A, the center of the workpiece 12 and the center axis Q of the rotary table 30 are matched to rotate the workpiece 12 to the center. Absent. For example, as shown in FIG. 5B, the center P1 of _one workpiece 12A may be offset with respect to the rotation center Q of the rotary table 30, and the workpiece 12 may be revolved. as such, three or four workpiece 12B, 12B ... 3 sheets of workpiece 12B each center _{P 2} is offset with respect to the rotation center Q of the rotary table 30, and also be revolved 12B ... Good.

  By rotating the objects 12A and 12B to be polished as shown in FIG. 5B and FIG. 5C, the grooves 17 of the polishing pad 16 are in random contact with the polishing surface of the object 12 as compared with the rotation type shown in FIG. 5A. Therefore, the flatness of the polished surface of the workpiece 12 is further improved.

Further, in the polishing apparatus 10 of the embodiment, as shown in FIG. 1, the clockwise revolution direction indicated by the arrow B of the polishing pad 16 (“revolution direction” or “revolution direction and rotation direction”) , and the polishing object 12 rotation direction Metropolitan counterclockwise indicated by an arrow C is set in the reverse direction.

Here, the rotation direction and direction of revolution of the polishing pad of the object to be polished (or revolution direction and rotation direction) is compared with a polishing apparatus which is set in the same direction, and a polishing apparatus 10 of the embodiment. In the polishing apparatus 10 of the embodiment, the relative speed of the polishing pad 16 passing through any one point on the polishing surface of the workpiece 12 is higher than that of the former polishing apparatus. Thereby, the polishing apparatus 10 according to the embodiment can improve the polishing efficiency and shorten the polishing time as compared with the former polishing apparatus.

  On the other hand, in the polishing apparatus of Patent Document 1 which is a continuous polishing apparatus and the object to be polished does not rotate, the polishing pressure decreases as the contact area of the polishing pad with the object to be polished increases, and the contact area decreases. Accordingly, the polishing pressure tends to increase. For this reason, in the polishing apparatus of Patent Document 1, the polishing allowance on the inner side of the object to be polished is smaller than that on the outer side, so that the distribution of the polishing allowance occurs on the polishing surface.

  On the other hand, the polishing apparatus 10 according to the embodiment has an advantage that the distribution of the polishing allowance can be relaxed because the workpiece 12 is rotated and the polishing pad 16 is translated.

  Further, the polishing pads 16, 16... Of the embodiment are revolved with an adjacent polishing pad 16 with a rotational phase difference.

  That is, as shown in FIG. 1, when polishing is performed with two polishing pads 16, 16 coming into contact with one object 12 during the conveyance of the object 12, each polishing pad 16, 16 The rotational phase difference of the mass center of gravity O is set to 180 degrees. When four polishing pads 16, 16... Are in contact with one object to be polished 12 for polishing, the rotational phase difference of the mass center of gravity O of each polishing pad 16, 16. Set to. Thus, the load acting on the object to be polished 12 can be offset by the rotational movement of each of the polishing pads 16, 16,..., So that the object to be polished 12 can be uniformly polished.

  In the embodiment, the disk-shaped workpiece 12 is illustrated, but the shape of the workpiece 12 is not limited to the disk shape, and may be a rectangular shape.

  However, as shown in FIG. 6A, when the rectangular object 12C is applied to a continuous polishing apparatus, the number of objects to be polished 12C mounted on the feed table 14 is reduced, resulting in a decrease in production efficiency. To do. That is, when the rectangular object 12C is rotated around its center of mass (the dashed line in the figure indicates the rotation trajectory of the edge of the object 12C), interference with the adjacent object 12C is caused. In order to prevent this, the object to be polished 12C must be mounted on the feed table 14 with the interval between adjacent objects to be polished 12C widened. As a result, the number of objects to be polished 12C mounted on the feed table 14 is reduced, so that the production efficiency is lowered.

  On the other hand, as shown in FIG. 6B, the disk-shaped object 12 is a continuous type having a rotary table 30 (see FIG. 2) that rotates around the center of mass of the object 12. In the polishing apparatus 10, it is not necessary to widen the interval between adjacent objects 12 to prevent interference. As a result, the number of objects to be polished 12 mounted on the feed table 14 is increased as compared with the rectangular object to be polished 12C, so that the production efficiency is improved.

  DESCRIPTION OF SYMBOLS 10 ... Polishing apparatus, 12 ... Object to be polished, 12A, 12B, 12C ... Object to be polished, 14 ... Feed table, 16 ... Polishing pad, 17 ... Groove, 18 ... Rail, 20 ... Adsorption sheet, 22 ... Rack, 24 ... Pinion, 25 ... rotating shaft, 26 ... polishing head, 28 ... revolving motion mechanism, 30 ... rotating table, 32 ... rotating shaft, 34 ... gear, 36 ... disk, 38 ... gear, 40 ... shaft

Claims (6)

A polishing apparatus that relatively presses an object to be polished and a polishing pad having a plurality of grooves in contact with the polishing surface of the object to be polished, and polishes the polishing surface of the object to be polished,
The plurality of grooves are parallel,
A rotating means for holding the non-polished surface of the object to be polished and rotating the object to be polished around a predetermined axis, and a revolution axis decentered with respect to the center of mass of the polishing pad. A polishing apparatus comprising: an operation means for rotating the center of mass while revolving or revolving . Wherein the rotation direction of the rotating means the object to be polished, the polishing apparatus according to claim 1 revolution direction of the polishing pad by the operation unit, or to the direction of revolution and rotation direction is set in the reverse direction. Conveying means for conveying the object to be polished in a predetermined direction together with the rotating means, and a plurality of the polishing pads are arranged on the conveying path of the object to be polished by the conveying means with a predetermined interval and being conveyed the polishing apparatus according to claim 1 or 2 of the you polish the surface of the object to be polished. The polishing apparatus according to claim 3 , wherein the polishing pad is revolved with an adjacent polishing pad with a rotational phase difference. It said rotating means, a disc-shaped the object to be polished, the polishing apparatus according to any one of claims 1 to 4 to be rotated about its center of mass. A method for polishing an object to be polished, comprising polishing the object to be polished using the polishing apparatus according to claim 1.

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