JP2001322056A - One-side grinding device and one-side grinding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To leave no such streaks as to cause a chip to break easily, on the chip by uniforming the direction of streaks left on a wafer after finish-grinding when finish-grinding by a one-side grinding device. SOLUTION: A finish-grinding wheel 3 formed of a cup type grinding wheel larger in diameter than a wafer W is rotated to finish-grind one side of the wafer W. At this time, the wafer W is at a stop without rotating, and the finish-grinding wheel 3 is linearly moved along the ground surface of the wafer W while abutting on the ground surface of the wafer W. The streaks on the ground surface of the wafer W ground by the finish-grinding wheel 3 can thereby be uniformed in circular arc shape swollen in the moving direction of the finish-grinding wheel 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an integrated circuit (IC).
The present invention relates to a single-side grinding apparatus and a single-side grinding method used for processing the back side of a wafer with an attachment.

[0002]

2. Description of the Related Art For example, when manufacturing an IC chip,
After manufacturing an IC (integrated circuit) on one side of a mirror-surface silicon wafer (hereinafter, referred to as a “wafer”), one side grinding of the wafer is performed as backside processing. In this case, first, rough grinding is performed on one side of the wafer using a cup-type grindstone provided with a rough grindstone. Then, after the rough grinding is completed in a plurality of stages using a plurality of rough whetstones having different roughnesses, the surface is further ground by a cup-type whetstone provided with a finishing whetstone for finish grinding.

FIG. 10 shows a conventional single-side grinding apparatus for grinding one side of a wafer. This single-side grinding device 50 has a spindle 51,
In the finish grinding, a finish grindstone 52 made of a cup-shaped grindstone is attached to the spindle 51. The finishing whetstone 52 has a whetstone part 52A for grinding the wafer W and a whetstone holding part 52B for holding the whetstone part 52A. The grindstone holding portion 52B is fixed to the spindle 51 by bolts B, B, and the finishing grindstone 52 rotates around the vertical axis Z1 together with the spindle 51. Further, the spindle 51 can be fed and moved in the axial direction (vertical direction).

On the other hand, below the spindle 51, a vacuum chuck 53 for vacuum-sucking a wafer W to be processed is provided. The vacuum chuck 53 is mounted on the rotary table 5.
The rotating table 54 is rotatably mounted on a support table 55 that is movable relative to the spindle 51. This turntable 54
The motor is rotationally driven around a vertical axis Z2 by a motor (not shown).

When the single-side grinding of the wafer is performed, streaks remain on the surface of the wafer. However, when one side of the wafer W is finish-ground by the conventional single-side grinding apparatus 50, FIG.
As shown in FIG. 5, streaks J, J,...

[0006]

As shown in FIG. 11A, a plurality of chips T, which are substantially rectangular in plan view, are cut out from the wafer W after the finish grinding is performed. . On the back surface of the cut-out chip T, streaks J, J,. At this time,
Chip T cut out from area E1 shown in FIG.
1 is shown in FIG. 11B, and the area E shown in FIG.
FIG. 11 (c) shows a chip T2 cut out from FIG. Now, the chip T1 cut out from the area E1 has
As shown in FIG. 1B, streaks J, J... Remain mainly along the longitudinal direction of the chip T. In such a case, even if an external force or impact in the warp direction is applied to the surface of the chip T, there is almost no fear that the chip T will be broken, and there is no particular problem. However, in the chip T2 cut out from the area E2, as shown in FIG. 11C, striations J, J,... Mainly remain along the lateral direction of the chip T2.
Such a chip T2 was relatively easily broken due to the warpage or the impact.

In this respect, when finish grinding is performed by the conventional single-side grinding apparatus 50, there is no problem with the streaks remaining on most of the chips T, but depending on the cutting position from the wafer W, a certain amount of streaks can be obtained. As shown in FIG. 11C, the streaks J, J mainly along the lateral direction of the chip T2.
… Will always remain. It is not preferable that such a chip T2 in which a streak mainly along the lateral direction remains, that is, a chip T2 that is easily broken is generated. In particular,
It is not easy to know where a chip having such a streak is generated, and it is very troublesome to find such a chip.

Accordingly, an object of the present invention is to provide a single-sided grinding machine which performs finish grinding by aligning the direction of the traces remaining on the wafer after the finish grinding as much as possible, thereby causing a crack which may cause chip breakage. For example, it is to prevent a streak along a short direction from being left on a chip.

[0009]

According to a first aspect of the present invention, there is provided a single-side grinding apparatus for grinding a single side of a workpiece by rotating a cup-type grindstone. When grinding one surface of the workpiece, the workpiece has moving means for relatively moving at least one of the grindstone and the workpiece in a linear direction along a ground surface of the workpiece, and The finish grindstone used for finish grinding is a cup-shaped grindstone having a larger diameter than the workpiece, and the workpiece is stopped in the rotation direction while the relative movement is being performed. A single-sided grinding device.

According to the first aspect of the present invention, when performing single-side grinding, the workpiece is stopped in the rotational direction, in other words, the finishing grindstone is rotated without rotating the workpiece. Can be relatively moved in a straight line direction along. For this reason, the streaks on the surface to be ground that have been ground by the finishing grindstone are uniformly left so as to have an arc shape that swells in the direction in which the finishing grindstone relatively moves. Therefore, by cutting the chip from the object to be ground so that the direction in which the streak extends is the longitudinal direction, it is possible to avoid leaving a streak that becomes a chip that is easily broken.

In the invention according to claim 2, the relative movement is:
The single-side grinding apparatus according to claim 1, wherein the apparatus includes one or more reciprocating movements.

According to the second aspect of the present invention, the finish grinding is performed a plurality of times, so that the surface of the workpiece can be finished and ground more accurately.

The invention according to claim 3 is the single-side grinding apparatus according to claim 1 or 2, wherein the diameter of the finishing grindstone is at least √2 times the diameter of the workpiece. is there.

According to the third aspect of the invention, the curvature of the streak remaining on the surface to be ground of the workpiece can be increased, and the streak becomes closer to a straight line. Can be more effectively prevented. In addition, it is preferable that the diameter of the finishing whetstone is twice or more the diameter of the workpiece.

According to a fourth aspect of the present invention, the finishing whetstone includes:
A grindstone fixedly provided on a spindle on which a grindstone mounting portion is formed.A rough grindstone made of a cup-type grindstone is mounted on the grindstone mounting portion formed on the spindle, and the diameter of the rough grindstone is The diameter of the finishing whetstone is smaller than the diameter of the finishing whetstone, and the rough whetstone is mounted so as to protrude from the finishing whetstone, and is arranged concentrically with the finishing whetstone. A single-side grinding apparatus according to any one of the preceding claims.

According to the fourth aspect of the present invention, since a rough grinding wheel and a finishing grinding wheel are provided, a series of grinding operations from rough grinding to finish grinding can be performed by one grinding apparatus.
In addition, since the rough grindstone and the finish grindstone are arranged concentrically on one spindle, the rough grindstone used for rough grinding and the finish grindstone used for finish grinding can be rotated by one spindle.

According to a fifth aspect of the present invention, there is provided an automatic tool changing device for automatically changing a rough whetstone attached to a whetstone mounting portion formed on the spindle.
2. The single-side grinding apparatus according to item 1.

According to the fifth aspect of the present invention, since an automatic tool changing device is provided for replacing a rough whetstone, the work of replacing a worn whetstone is facilitated and a great deal of labor is not required for an operator. In addition, the grinding operation can be performed in a short time. In addition, since the rough grinding operation can be performed in a plurality of stages by exchanging whetstones having different roughnesses by the automatic tool changer, the grinding operation can be efficiently performed as a whole.

According to a sixth aspect of the present invention, there is provided a shutter which can be opened and closed at a position lateral to the rough grinding stone in the finishing grinding stone and covers the finishing grinding stone while the rough grinding stone is being ground. The single-side grinding apparatus according to claim 4 or claim 5, wherein:

According to the sixth aspect of the present invention, since the shutter for covering the finishing whetstone is provided during the rough grinding, grinding debris and the like are scattered on the finishing whetstone during the rough grinding. This can prevent the finishing whetstone from being soiled. In addition, since the shutter is openable and closable, the finish grinding by the finishing whetstone can be easily performed by opening the shutter when performing finish grinding.

The invention according to claim 7 is characterized in that the length of a part of the finishing whetstone located on the side of the rough whetstone is longer than the diameter of the workpiece. Item 7. The single-side grinding device according to any one of Items 6.

According to the seventh aspect of the present invention, the finish grinding with the finishing whetstone can be performed while the rough whetstone is attached to the spindle. For this reason, the operation of removing the rough whetstone can be omitted, and a series of grinding operations can be performed more efficiently.

The invention according to claim 8 is characterized in that, when the finish grindstone is rotated to finish-grind one surface of the workpiece, a cup-shaped grindstone having a diameter larger than that of the workpiece is used as the finish grindstone. While the workpiece is stopped in the rotation direction, at least one of the finishing whetstone and the workpiece is brought into contact with the workpiece while the finishing whetstone is in contact with the grinding surface of the workpiece. A single-side grinding method characterized by performing a finish grinding of the workpiece by relatively moving the workpiece in a linear direction along a grinding surface.

According to the eighth aspect of the present invention, when performing single-side grinding, the workpiece is stopped in the rotation direction, in other words, the finishing grindstone is rotated without rotating the workpiece. Can be relatively moved in a straight line direction along. For this reason, the streaks on the surface to be ground that have been ground by the finishing grindstone are uniformly left so as to have an arc shape that swells in the direction in which the finishing grindstone relatively moves. Therefore, by cutting the chip from the object to be ground so that the direction in which the streak extends is the longitudinal direction, it is possible to avoid leaving a streak that becomes a chip that is easily broken.

According to a ninth aspect of the present invention, when one side of a workpiece is roughly ground with a rough grindstone, the finishing grindstone is rotated to finish grind, and a cup-type grindstone is used as the rough grindstone. Using a cup-type grindstone having a diameter larger than that of the workpiece, performing rough grinding of the workpiece while rotating the rough grinding wheel and the workpiece, and then stopping the workpiece in the rotation direction. While keeping the finishing whetstone in contact with the surface to be ground of the workpiece, at least one of the finishing whetstone and the workpiece is linearly moved along the surface to be ground of the workpiece. A single-side grinding method characterized by performing finish grinding of the workpiece by relative movement.

According to the ninth aspect of the present invention, since rough grinding can be performed before finish grinding, a series of operations from rough grinding to finish grinding can be performed.

The invention according to claim 10 is the single-side grinding method according to claim 8 or claim 9, wherein the relative movement includes one or more reciprocating movements.

According to the tenth aspect of the present invention, since the finish grinding is performed a plurality of times, the surface of the workpiece can be finished and ground more accurately.

[0029]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a front sectional view of a main part of a single-side grinding device according to a first embodiment of the present invention. As shown in FIG. 1, a single-side grinding apparatus 1 according to the present embodiment has a spindle 2, and a cup-type finishing grindstone 3 is attached to the spindle 2. The finishing whetstone 3 includes a whetstone part 3A and a whetstone holding part 3B. As shown in FIG. 2, the grindstone portion 3A is formed in a ring shape having a width L of, for example, 20 to 30 mm.
It is fixed to the grindstone holder 3B.

The whetstone holding portion 3B includes bolts 3C, 3C.
The wheel 2 is fixed to the spindle 2 by C, and together with the spindle 2, the grindstone holding unit 3B rotates and the grindstone unit 3A rotates around the vertical axis Z1. Further, the spindle 2 can be moved in a linear direction that horizontally connects a center of the spindle 2 and a center of a vacuum chuck 4 described later by a horizontal moving mechanism that is a moving unit (not shown).

On the other hand, below the spindle 2, the wafer W
Is provided with a vacuum chuck 4 made of a porous material that vacuum-adsorbs the surface. A suction tube (not shown) is provided below the vacuum chuck 4, and by suctioning the wafer W from the suction tube via the vacuum chuck 4,
The surface of the wafer W is vacuum-sucked. The vacuum chuck 4 is fixedly attached to a support table 5. Therefore, the wafer W does not rotate. Further, as shown in FIG. 2, the radius R3A of the grindstone portion 3A of the finishing grindstone 3 is larger than the radius RW of the wafer W, for example, 200 mm, and the roughness of the grindstone portion 3A is, for example, a mesh size of ♯. It is said to be 2,000. Further, the diameter of the grindstone portion 3A of the finishing grindstone 3 is set to be approximately √2 times the diameter of the wafer W.
Further, the diameter of the grindstone portion 3A of the finishing grindstone 3 can be set to twice or more the diameter of the wafer W.

Next, a single-side grinding method of the wafer W by the single-side grinding apparatus 1 according to the present embodiment will be described with reference to FIG. Before starting single-side grinding, the spindle 2 is arranged at the left position so that the spindle 2 and the vacuum chuck 4 do not overlap in the vertical direction. In this state, the finishing grindstone 3 is fixed to the spindle 2 by bolts 3C, 3C. On the other hand, a wafer W to be processed is placed at the center of the vacuum chuck 4, and the surface of the wafer W is vacuum-sucked via a vacuum chuck 4 from a suction pipe (not shown).
An IC (integrated circuit) is formed on the front surface of the wafer W, and the back surface to be ground is after rough grinding has been performed by a rough grindstone (not shown).

When the surface of the wafer W is vacuum-sucked by the vacuum chuck 4, the spindle 2 is rotated about its axis Z1, and the spindle 2 is rotated by a horizontal moving mechanism (not shown) in the direction of the wafer W suction-held by the vacuum chuck 4. To move horizontally straight. At this time, the wafer W is held in a stopped state without rotating.

When the spindle 2 is moved horizontally in the direction of the wafer W, the spindle 2 passes above the wafer W as shown in FIG. Spindle 2 above wafer W
When the grinding wheel 3 has passed, the grinding portion 3A of the finishing grindstone 3 is linearly moved along the grinding surface of the wafer W while being in contact with the grinding surface of the wafer W, and finish grinding is performed. Then, when the spindle 2 completely passes above the wafer W, finish grinding of the wafer W is completed. Here, since the finishing whetstone 3 is formed to be larger in diameter than the wafer W,
By passing once through the back surface of the wafer W, finish grinding of the entire back surface of the wafer W can be performed. The finish grinding may be completed once, but may be performed a plurality of times including one or more reciprocating linear movements.

After the back surface of the wafer W has been ground with the finishing grindstone 3, the striations J, J shown in FIG.
... remains. These streaks J, J...
(The right side in FIG. 4 (a)) remain in a bulging arc shape. Therefore, chip T,
By cutting the chips so that the longitudinal direction of T... Faces the vertical direction of the wafer W, even if the chips T are cut from any part of the wafer W, as shown in FIG. The streaks J, J... Remain mainly along the vertical direction. Therefore, it is possible to avoid a state in which the streak remains along the lateral direction of the chip. Since the orientation of the wafer W can be confirmed by the position of a notch (not shown), it is possible to prevent a streak from remaining along the lateral direction of all chips. For this reason, it is possible to prevent a chip that is easily broken.

Next, a second embodiment of the present invention will be described. FIG. 5 is a front sectional view of a main part of the single-side grinding device according to the present embodiment. As shown in FIG. 5, the single-side grinding apparatus 10 according to the present embodiment has a spindle 12, and a finishing grindstone 13 made of a cup-shaped grindstone is attached to the spindle 12. The finishing whetstone 13 is the same as that used in the first embodiment, and has a whetstone portion 13A and a whetstone holding portion 13B. The whetstone holding portion 13B is connected to the spindle 12 by bolts 13C and 13C.
It is tightened and fixed. Also, spindle 1
2 can be moved by a horizontal moving mechanism (not shown) in a linear direction horizontally connecting the center of the spindle 12 and the center of a vacuum chuck 17 described later, as in the first embodiment.

Further, the finishing whetstone 1 is mounted on the spindle 12.
A grinding wheel mounting portion 14 which is concentric with 3 and is formed of a mounting hole having a tapered shape is formed. This whetstone mounting part 14
Above the draw bar 14A and the ball 14
A well-known pull stud clamp mechanism composed of B and 14B is provided.

A rough grindstone 15 made of a cup-shaped grindstone is mounted on the grindstone mounting portion 14. The rough whetstone 15 has a tapered shank portion 15A fitted to the whetstone mounting portion 14, and a holder portion 15B is formed in front of the shank portion 15A (downward in the illustrated state).
Further in front of the holder portion 15B, a hollow cylindrical grindstone portion 15C is fixed. As the grindstone portion 15C, a rough grindstone having a mesh size of about $ 600, for example, is used. Further, a pull stud 15D is provided behind the shank 15A. When the rough whetstone 15 is fitted to and mounted on the whetstone mounting part 14, the pull stud 15D is moved to the draw bar 14A by the ball 1
The rough whetstone 15 is attached to a fixed position clamped to the whetstone mounting portion 14 by being pulled across the 4B and 14B.

Further, as shown in FIG.
A tool changing arm 16 which is an automatic tool changing device is provided on a side of the tool changing arm 2. As the tool changing arm 16, an arm usually used in a machining center or the like can be used. And this tool change arm 16
Thereby, the rough grindstone 15 can be replaced with one rough grindstone 15 'of a plurality of rough grindstones stored in a grindstone stocker (not shown). Further, the rough grindstone 15 'to be replaced also has a shank part 15A', a holder part 15B ', a grindstone part 15C' and a pull stud 15D ', like the old rough grindstone 15. The grindstone portion 15C 'used here has, for example, a mesh size of # 1.
A grindstone having a roughness of about 200 or a medium is used. In addition,
A grindstone stocker (not shown) can store a rough grindstone holder having a rough grindstone having the same mesh size, or can store a rough grindstone holder having a plurality of types of rough grindstones having different mesh sizes. .

When replacing the rough whetstones 15 and 15 ',
The holder 15B of the used rough grindstone 15 is gripped by the first gripper 16A of the tool changing arm 16, and a new rough grindstone 1 is formed.
The 5 'holder 15B' is gripped by the second grip 16B of the tool changing arm 16. Then, the tool changing arm 16 is rotated by 180 ° around a rotation axis 16C extending in the vertical direction by a drive motor (not shown), so that the rough grindstones 15 and 1 are rotated.
Replace 5 '. If the rough grinding wheel holder is not mounted on the grinding wheel mounting portion 14, the holder portion 15B of the rough grinding wheel 15 stored in the grinding wheel stocker is gripped by the second grip portion 16B of the tool changing arm 16, and the tool changing arm The new rough whetstone 15 ′ can be mounted on the whetstone mounting part 14 by rotating the 16 by 180 °.

Below the spindle 12, there is provided a vacuum chuck 17 made of a porous material for concentrically arranging the wafer W and vacuum-sucking. The vacuum chuck 17 is provided concentrically on a rotary table 18, and the rotary table 18 is rotatably attached to a support table 19. The rotary table 18 is driven to rotate by a motor (not shown).

Further, shutters S, S which can be opened and closed are provided on the side of the rough grindstone 15. The shutters S, S are closed when rough grinding is performed,
It prevents the grinding chips from scattering due to rough grinding on the finishing whetstone.

By using the grindstone grinding apparatus according to this embodiment, a series of grinding operations from rough grinding to finish grinding can be performed. Hereinafter, a single-side grinding method by the single-side grinding apparatus according to the present embodiment will be described with reference to FIGS.

First, before the grinding process is performed, the state in which the rough grindstone 15 is not attached to the grindstone attaching portion 14 is changed to the second holding portion 16B of the tool changing arm 16 shown in FIG.
Thus, the rough grinding stone 15 is gripped, and the tool exchange arm 16 is rotated by 180 ° around the rotation axis 16C, so that the rough grinding stone 15 is positioned below the grinding wheel mounting portion 14. Next, the spindle 12
Is lowered to fit the shank portion 15A of the rough whetstone 15 to the whetstone mounting portion 14. When the shank portion 15A of the rough whetstone 15 is fitted into the mounting hole 14a of the whetstone mounting portion 14, the rough whetstone 1
The pull stud 15D of No. 5 is pulled by the draw bar 14A, the rough whetstone 15 is clamped, and the rough whetstone 15 is attached to the whetstone mounting portion 14.

When the rough whetstone 15 is mounted on the whetstone mounting portion 14, the tool changing arm 16 is retracted. And FIG.
As shown in (a), the spindle 12 is moved until the width center of the grindstone portion 15C substantially coincides with the rotation center of the turntable 18, and the shutters S, S are closed. Then, after lowering the spindle 12, the spindle 12
In addition to rotating the finishing grindstone 15 about a vertical axis, the rotating table 18 that concentrically holds the wafer W via the vacuum chuck 17 is also rotated. Thus, rough grinding of the ground surface of the wafer W is performed by the grindstone portion 15C attached to the rough grindstone 15.

Here, the rough grinding with the rough grindstone 15 is performed until the thickness of the wafer W becomes a thickness suitable for performing the finish grinding. However, there are cases where the rough grinding is performed only once. In some cases, two or more stages of rough grinding are performed by a plurality of types of rough grinding wheels. When rough grinding is performed in two or more stages by rough grinding wheels having different roughnesses, the tool changing arm 16 automatically replaces the rough grinding wheels 15, 15 '. In addition, when performing rough grinding in a plurality of stages with a rough grindstone having the same roughness, when the rough grindstone becomes severely worn, the rough grindstone can be automatically replaced by an automatic tool changing device.

When the rough grinding by the rough grinding stone 15 is completed, the spindle 12 is raised, the shutters S, S are opened, and the rough grinding stone 15 is removed from the spindle 12 by the tool changing arm 16 shown in FIG. To illustrate this procedure,
In order to remove the rough grinding stone 15, the spindle 12 is raised and the spindle 12 is moved to return the spindle 12 to the position before the rough grinding. Subsequently, the tool changing arm 16 is returned to the position shown in FIG. 6, and the first holding portion 16A of the tool changing arm 16 holds the holder 15B of the rough whetstone 15 attached to the whetstone mounting portion 14. On the other hand, the second grip 16B of the tool change arm 16 does not grip anything. Then, change the tool change arm 16 to the vertical shaft 16C.
Rotate 180 ° around. Thus, the spindle 12
The rough whetstone 15 is removed from.

When the rough whetstone 15 is removed, the finishing whetstone 1
The spindle 12 is lowered so that the lower surface of the grindstone portion 13A in 3 is slightly lower than the upper surface of the wafer W. Then, as shown in FIG. 7B, the spindle 12 is rotated about its axis Z1, and the spindle 12 is moved horizontally by a horizontal moving mechanism (not shown) in the direction of the wafer W suction-held by the vacuum chuck 17. Move. At this time, the wafer W is held in a stopped state. By performing such finish grinding,
The finish grinding similar to that of the first embodiment is performed, and as shown in FIG. 4, the streaks J, J... Remaining on the wafer W are in the direction in which the finish grindstone 3 passes uniformly (FIG. 4A). On the right)
Are arranged so as to form a bulging arc shape. Therefore, as shown in FIG. 4 (b), the chip is cut out so that the streaks J, J,... In the chip T are mainly along the vertical direction, so that the streaks remain along the short direction of the chip. Since such a state can be avoided, a chip that is easily broken can be prevented from being generated.

Next, a third embodiment of the present invention will be described. FIG. 7 is a side sectional view of the single-side grinding device according to the present embodiment. As shown in FIG. 7, the single-side grinding apparatus 20 according to the present embodiment has a spindle 22, and a finishing grindstone 23 made of a cup-shaped grindstone is attached to the spindle 22. This finishing whetstone 23 has a whetstone part 23
A and a grinding wheel holding portion 23B.
B is fastened and fixed to the spindle 22 by bolts 23C, 23C. These bolts 23C, 23
The portion fixed by C is the grindstone mounting portion. The spindle 22 can be moved by a horizontal moving mechanism (not shown) in a linear direction that horizontally connects the center of the spindle 22 and the center of a vacuum chuck 27 described later, similarly to the above embodiments.

Further, a rough grindstone 25 made of a cup-shaped grindstone is fixed to the spindle 22 concentrically with the finish grindstone 23. The rough grindstone 25 has a grindstone portion 25A and a grindstone holding portion 2.
5B, and the whetstone holding portion 25B is
C and 25C are fastened and fixed to the spindle 22.

In the single-side grinding device 20 according to the present embodiment, the length of the portion of the finishing grindstone 23 located on the side of the rough grindstone is set longer than the length of the wafer W. Therefore, finish grinding can be performed by the finish grindstone 23 without removing the rough grindstone 25.

A vacuum chuck 27 made of a porous material for vacuum-sucking the wafer W is disposed below the spindle 22, as in the second embodiment. The vacuum chuck 27 is provided concentrically on a rotary table 28, and the rotary table 28 is rotatably attached to a support table 29. This rotary table 28
Are driven to rotate by a motor (not shown).

Next, the single-side grinding device 20 according to the present embodiment
Will be described. As shown in FIG. 7, in the single-side grinding device 20 according to the present embodiment, the center of the grindstone width of the grindstone portion 25C of the rough grindstone 25 is
The center of rotation is substantially coincident with the center of rotation. In this state, spindle 2
2 is rotated about the vertical axis Z1, and the rotary table 28 is rotated about the vertical axis Z2 to perform rough grinding. This rough grinding may be performed only in one stage, as in the second embodiment, or may be performed in two or more stages using a plurality of types of rough grinding wheels.

When the rough grinding by the rough grinding stone 25 is completed, the spindle 22 is moved to the near side. At this time, the wafer W is positioned so as to be located on the side of the rough grinding stone 25 as shown by a virtual line in FIG. The spindle 22 is moved. Subsequently, the spindle 22 is further lowered (in the state shown by the phantom line in FIG. 7, the support table 29 is drawn so as to rise), and the grindstone portion 23A of the finishing grindstone 23 moves the wafer W
Of the surface to be ground. Subsequently, the spindle 22 is rotated, and the spindle 22 is moved by a horizontal moving mechanism (not shown) from the near side to the back side of the paper in a state shown by a virtual line in FIG. At this time,
The rotary table 28 is stopped, and the wafer W is not rotated. Thus, on the ground surface of the wafer W after the finish grinding is completed, as shown in FIG.
The streaks J, J... Closer to a straight line than the streaks J, J... Formed on the wafer W that has been single-side ground according to the first and second embodiments remain in an arc shape. . Therefore, as shown in FIG. 9 (b), the chip is cut out such that the streaks J, J... In the chip T are mainly along the vertical direction, so that the streaks remain along the short direction of the chip. Can be avoided, so that a chip that is easily broken can be prevented from being generated.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, in the third embodiment, a shutter as shown in the second embodiment can be provided, or an embodiment having an automatic tool changer can be provided. Further, in each of the above embodiments, the wafer is vacuum-sucked from below and the cup-shaped grindstone is provided on the upper side. However, it is also possible to adopt a mode in which this is reversed. Furthermore, in order to make the streak remaining on the wafer close to a straight line, the diameter of the finishing grindstone may be increased, but if the diameter of the finishing grindstone is too large, the grinding device will be enlarged,
It is preferable to use a finishing whetstone of an appropriate size. Further, in each of the above embodiments, the finish grindstone side is horizontally linearly moved when performing finish grinding,
It is also possible to adopt a mode in which the wafer side is moved linearly horizontally without moving the finishing whetstone. Of course, it is also possible to adopt a mode in which both the finishing whetstone and the wafer are moved. Furthermore, since the finishing grindstone and the wafer are moved along the grinding surface of the wafer, for example, depending on the direction in which the wafer is fixed, the finishing grindstone and the wafer may be moved in a vertical direction. However, when the finishing whetstone and the wafer are moved, they are moved linearly.

Alternatively, the outer periphery of the surface to be ground of the cup-type grindstone is usually circular, but this does not prevent an oval shape or the like. Also, the workpiece is not limited to a circular shape. At these times, when performing single-side grinding of the workpiece by rotating the cup-shaped grindstone on which the workpiece rotates, the diameter of the finishing grindstone is a circle formed by rotating a point farthest from the center of the rotating finishing grindstone. Means diameter.

[0057]

As described above, according to the first aspect of the present invention, it is possible to align the marks on the surface to be ground which has been ground by the finishing whetstone in a direction in which the finishing whetstone is moved in the moving direction. it can. Therefore, by cutting a rectangular chip from the object to be ground along the direction in which the streak extends, it is possible to prevent a streak that becomes a chip that is easily broken from being left. In addition, the shape of the chip is not limited to a rectangle, and may be a square chip. In this case, the chip is cut out along the 45-degree streaks so that the chip is hard to be broken in any of the vertical and horizontal directions of the chip. Can be cut out.

According to the second aspect of the invention, the surface of the workpiece can be finish-ground with higher accuracy.

According to the third aspect of the present invention, the curvature of the streaks remaining on the surface to be ground of the workpiece can be reduced, so that the generation of chips that are easily broken can be more effectively prevented. it can.

According to the fourth aspect of the present invention, a series of grinding operations from rough grinding to finish grinding can be performed by one grinding device. The finishing whetstone used can be rotated.

According to the fifth aspect of the present invention, the work of replacing the worn whetstone is facilitated, and the grinding work can be performed in a short time without applying much labor to the operator. In addition, since a plurality of rough grinding operations can be performed by replacing the grindstones with different roughnesses, the grinding operation can be efficiently performed as a whole.

According to the sixth aspect of the present invention, it is possible to prevent grinding dust and the like from scattering on the finishing grindstone during the rough grinding and contaminating the finishing grindstone.
Moreover, when performing the finish grinding, the finish grinding with the finish grindstone can be easily performed by opening the shutter.

According to the seventh aspect of the present invention, the finish grinding with the finishing whetstone can be performed while the rough whetstone is attached to the spindle, so that the work of removing the rough whetstone can be omitted, and the efficiency can be further improved. Can perform a series of grinding operations.

According to the invention of claim 8, the streaks on the surface to be ground which has been ground by the finishing grindstone can be aligned in the direction in which the finishing grindstone is separated in the moving direction. Therefore, by cutting out the chip from the object to be ground along the direction in which the streak extends, it is possible to avoid leaving a streak which becomes a chip that is easily broken.

According to the ninth aspect of the present invention, since the rough grinding before the finish grinding can be performed, a series of operations from the rough grinding to the finish grinding can be performed.

According to the tenth aspect, the surface of the workpiece can be finish-ground with higher precision.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a main part of a single-side grinding apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view of a grindstone portion of the single-side grinding device according to the first embodiment of the present invention.

FIG. 3 is a front sectional view showing a state where single-side grinding is performed by the single-side grinding apparatus according to the first embodiment of the present invention.

FIG. 4A is a plan view showing a streak remaining on a wafer after performing single-side grinding by the single-side grinding apparatus according to the first embodiment of the present invention, and FIG. It is a top view which shows the streak which remains on the chip | tip cut out from FIG.

FIG. 5 is a front sectional view of a main part of a single-side grinding apparatus according to a second embodiment of the present invention.

FIG. 6 is a front sectional view of a main part of the single-side grinding device showing a state in which a rough grinding wheel holder is replaced with another rough grinding wheel holder.

FIG. 7A is a front sectional view showing a state in which rough grinding is performed by a single-side grinding device according to a second embodiment of the present invention, and FIG. 7B is a state in which finish grinding is being performed; It is a front sectional view.

FIG. 8 is a front sectional view of a single-side grinding device according to a third embodiment of the present invention.

FIG. 9A is a plan view showing a streak remaining on a wafer after performing single-side grinding by a single-side grinding apparatus according to a third embodiment of the present invention, and FIG. It is a top view which shows the streak which remains on the chip | tip cut out from FIG.

FIG. 10 is a front sectional view of a main part of a conventional single-side grinding apparatus.

11A is a plan view showing a streak remaining on a wafer after one-side grinding has been performed by a conventional one-side grinding apparatus, and FIG. 11B is a chip cut out from an area E1 of the wafer. (C) is a plan view showing a streak remaining on a chip cut out from the area E2 of the wafer.

[Explanation of symbols]

 1,10 Single-side grinding device 2,12 Spindle 3,13 Finishing grindstone 3A Grindstone part 3B Grindstone holding part 4,17 Vacuum chuck 5,18 Rotary table 6,19 Support table 14 Grindstone attaching part 15 Rough grindstone 15A Shank part 15B Holder part 15C Grinding stone part 15D Pull stud 16 Tool change arm J Streak W Wafer S Shutter

Claims (10)

[Claims] 1. A single-side grinding device for rotating a cup-type grindstone to grind one surface of a workpiece, wherein at least one of the grindstone and the workpiece is ground when grinding one surface of the workpiece. Along with a moving means for relatively moving in a linear direction along the surface to be ground in the workpiece, a finishing grindstone used for finish grinding of the workpiece is a cup-type grindstone having a larger diameter than the workpiece. And a single-side grinding apparatus characterized in that the workpiece is stopped in a rotational direction while the relative movement is being performed. 2. The single-side grinding apparatus according to claim 1, wherein the relative movement includes one or more reciprocating movements. 3. The single-side grinding apparatus according to claim 1, wherein the diameter of the finishing whetstone is at least √2 times the diameter of the workpiece. 4. The finishing whetstone is a whetstone fixedly provided on a spindle on which a whetstone mounting portion is formed, and a rough whetstone made of a cup-type whetstone is provided on the whetstone mounting portion formed on the spindle. The diameter of the rough whetstone is smaller than the diameter of the finishing whetstone, and the rough whetstone is mounted so as to protrude beyond the finishing whetstone, and is arranged concentrically with the finishing whetstone. The single-side grinding device according to any one of claims 1 to 3, wherein 5. The single-side grinding apparatus according to claim 4, further comprising an automatic tool changer for automatically changing a rough grindstone attached to a grindstone mounting portion formed on the spindle. 6. A shutter that is openable and closable at a position lateral to the finishing whetstone relative to the rough whetstone and that covers the finishing whetstone during grinding by the rough whetstone is provided. The single-side grinding device according to claim 4 or 5, wherein: 7. The finishing wheel according to claim 4, wherein a length of a portion of the finishing wheel located on a side of the rough wheel is longer than a diameter of the workpiece. The single-side grinding apparatus according to claim 1. 8. When the finish grindstone is rotated to finish-grind one surface of the workpiece, a cup-type grindstone having a diameter larger than that of the workpiece is used as the finish grindstone, and the workpiece is rotated in the rotation direction. While stopping, at least one of the finishing whetstone and the workpiece is linearly moved along the grinding surface of the workpiece while the finishing whetstone is in contact with the grinding surface of the workpiece. A single-sided grinding method, wherein the workpiece is finish-ground by being relatively moved in a direction. 9. After rough grinding one surface of a workpiece with a rough grindstone and then rotating the finishing grindstone to finish grind, a cup-type grindstone is used as the rough grindstone, and the workpiece grindstone is used as the finishing grindstone. After performing rough grinding of the workpiece while rotating the rough grinding stone and the workpiece using a large-diameter cup-shaped grindstone, the workpiece is stopped in a rotating direction, and the finishing is performed. While making the grindstone contact the ground surface of the workpiece, at least one of the finishing whetstone and the workpiece is relatively moved in a linear direction along the ground surface of the workpiece, A single-side grinding method characterized by performing finish grinding of a workpiece. 10. The single-side grinding method according to claim 8, wherein the relative movement includes one or more reciprocating movements.