JP2019198898A - Chamfering grinding device - Google Patents

Abstract

To provide a chamfering grinding device using a grinding tape, which can create a shape of a work-piece into various shapes of chamfering and is superior in stability of chamfering quality.SOLUTION: The chamfering grinding device comprises a rotary table on which a disk-like work-piece is placed and rotation thereof is controlled, and a grinding tape that is contacted with a peripheral end part of the work-piece to perform chamfering grinding. The grinding tape, attached to a tape holding device having a feeding-out part and a winding-up part, is protruded toward the peripheral end part of the work-piece by a back-up roller provided in the tape holding device. With respect to a relative moving locus of the back-up roller and the work-piece, an X-axis in a horizontal direction, a Z-axis in a vertical direction and a c-axis around the Z-axis are synchronously controlled by an NC program.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a grinding apparatus for chamfering a peripheral end portion of a workpiece having a disk shape such as a wafer used in a semiconductor device, and more particularly to a grinding apparatus using a grinding tape.

Brittle materials such as silicon crystal substrates, silicon carbide substrates, quartz substrates, and sapphire substrates are used for wafers used in semiconductor devices.
If these materials have sharp edges at the ends, they may be cracked or partially chipped during handling.
In addition, the surface of another wafer may be damaged.
In this type of chamfering, a rotating grindstone is used, but there is also a technical problem that the chamfering shape changes due to wear of the grindstone. Therefore, a technique using an abrasive tape instead of this grindstone is disclosed in Patent Documents 1, 2, etc. Is disclosed.
The technology disclosed in these is a technique in which a movable roller or the like is pressed against the work using a cylinder to bring the polishing tape into contact with the work, and the peripheral edge of the work is chamfered to the extent that it is rubbed by copying with controlled load. Even if it is possible, it does not have enough glass cutting power to create various chamfered shapes.

JP 2014-58038 A JP 2011-93057 A

  An object of the present invention is to provide a chamfering and grinding apparatus using a grinding tape that can create shapes in various chamfered shapes and has excellent chamfering quality stability.

  A chamfering grinding apparatus according to the present invention comprises a rotary table for placing and controlling rotation of a disk-shaped workpiece, and a grinding tape for performing chamfering grinding in contact with a peripheral edge of the workpiece, and the grinding tape is sent out. And a backup roller provided in the tape holding device and projecting toward the peripheral end of the work, and the backup roller and the work The relative movement trajectory is characterized in that the horizontal X axis, the vertical Z axis, and the C axis around the Z axis are controlled synchronously by the NC program.

  A grinding tape is made by adhering abrasive grains to the surface of a ribbon-like tape, and has a take-up part such as a take-up roller for taking up the fed-out part and a feed-out part such as a feed roller. The tape can be fed from one roller and the tape fed by the other roller can be taken up. However, the grinding tape may be reciprocated by reversing the rotation directions of the rollers.

In the present invention, the back-up roller moves between the upper surface side and the lower surface side of the peripheral end portion while pressing the grinding tape against the peripheral end portion of the workpiece from the back side, so that the movement locus becomes the chamfered shape of the workpiece.
Therefore, the back roller is for pressing the grinding tape strongly to the extent that the peripheral edge of the workpiece can be ground.
In this respect, Patent Document 1 is different from pressing while applying minute vibrations with a cylinder.

In the present invention, the workpiece is placed on the rotary table in a state where the peripheral end portion is overhanged by a predetermined dimension from the outer peripheral end portion of the rotary table, and the overhang amount H is the thickness Tmm of the workpiece. On the other hand, it is preferably set within 10 × Tmm. In this case, the outer peripheral radius R of the backup roller is preferably ½ or less of the overhang amount H.
A wafer having a diameter of 10 to 300 mm is often used, and a wafer having a thickness of 200 to 800 μm is used according to the size.
When the overhang amount H becomes large, it becomes unstable during chamfering.
Therefore, the overhang amount H is set within 10 × Tmm, and preferably H is set within 5 × Tmm.

In the chamfering grinding apparatus according to the present invention, the relative movement restriction of the X axis direction, the Z axis direction, and the C axis between the back roller and the workpiece is controlled by the NC program synchronously. Can be formed and created in various shapes, so there is a high degree of freedom in setting chamfered shapes.
Further, when elastic deformation occurs in the back roller, the deformation amount can be corrected by the NC program.
Since the grinding tape can supply new abrasive grains to the processing point, problems such as a change in the quality of the chamfered shape due to wear and replacement of the grinding wheel as in the conventional grinding stone do not occur.

(A) shows the structural example of the chamfering grinding apparatus which concerns on this invention, (b) shows the movement locus | trajectory of a back roller. An example of the creation of a chamfered shape at the peripheral edge of a workpiece will be shown.

Although the structural example of the chamfering grinding apparatus which concerns on FIG. 1 at this invention is shown, this invention is not limited to this.
As shown to Fig.1 (a), it has the rotary table 2 which mounts and hold | maintains the disk-shaped workpiece | work 1 in the centered state.
The turntable 2 is driven by placing, not shown are rotationally controlled in the rotational speed W _1, to hold the workpiece 1 on the turntable 2 by using a retaining means such as a vacuum suction port.
The disk-shaped work 1 is placed on the turntable 2 in an overhang state from the outer peripheral end (outer peripheral wall) 2a of the turntable 2 by an overhang amount Hmm.

The tape holding device 3 includes a feed roller 3 b and a take-up roller 3 c for the grinding tape 4 and a backup roller 3 a for pressing the grinding tape 4 against the peripheral end of the work 1.
The backup roller 3 a is for pressing the grinding tape 4 from the back side in order to grind the peripheral end portion 1 a of the workpiece 1 into various chamfered shapes, and protrudes from the main body portion of the tape holding device 3.
The grinding tape 4 is stretched using a guide roller 3d, a tension roller 3e, and the like.
Therefore, the backup roller 3a is supported by protruding from the main body of the tape holding device 3 using a rigid frame material or the like.

  The backup roller 3a of the tape holding device 3 and the work 1 placed on the rotary table 2 are provided with a movement control mechanism (not shown) on one or both of the backup roller 3a and the rotary table 2, and can be controlled by an NC program. The positions of the horizontal X-axis, the vertical Z-axis, and the C-axis around the Z-axis are controlled synchronously.

As shown in FIG. 1B, the backup roller 3a moves between the chamfered upper surface 1b, the chamfered tip 1c, and the chamfered lower surface 1d of the peripheral edge of the workpiece so as to be ground into a desired chamfered shape.
In FIG. 1B, the movement locus of the backup roller 3a is indicated by a two-dot chain line, and the center locus of the backup roller 3a is indicated by a one-dot chain line.
When grinding the chamfered lower surface 1d at the peripheral edge of the workpiece, the radius R of the backup roller 3a is ½ or less of the overhang amount H in order to avoid interference with the outer peripheral wall 2a of the rotary table 2. It is set as follows.
At this time, the thickness of the grinding tape 4 also needs to be taken into consideration, but the grinding tape is thin, so that portion is omitted.

  When chamfering and grinding the peripheral edge of the workpiece with the grinding tape 4, if the grinding tape 4 is reciprocated in the longitudinal direction or the width direction, or the tape path of the roller is changed in the width direction, the grinding dust is discharged. Can be promoted.

FIG. 2 shows an example in which the grinding allowance is set to be different between the lower surface side and the upper surface side with respect to the grinding region 1e at the peripheral end portion of the workpiece.
Thereby, the shape of the chamfered upper surface 1b and the chamfered lower surface 1d can be set freely.

1 Workpiece 2 Rotary table 3 Tape holding device 3a Backup roller 4 Grinding tape

Claims (3)

A rotary table for placing and controlling the rotation of a disk-shaped workpiece, and a grinding tape for chamfering grinding by contacting the peripheral edge of the workpiece,
The grinding tape is mounted on a tape holding device having a delivery portion and a winding portion, and is projected toward the peripheral end of the workpiece by a backup roller provided on the tape holding device,
The relative movement trajectory between the backup roller and the workpiece is controlled by an NC program in which the horizontal X axis, the vertical Z axis, and the C axis around the Z axis are controlled synchronously. Grinding equipment. The workpiece is placed on the rotary table in a state where the peripheral end portion is overhanged by a predetermined dimension from the outer peripheral end portion of the rotary table,
The chamfering grinding apparatus according to claim 1, wherein the overhang amount H is set within 10 × Tmm with respect to the thickness Tmm of the workpiece.   The chamfering grinding apparatus according to claim 2, wherein an outer peripheral radius R of the backup roller is ½ or less of the overhang amount H.

Images