JP2007296601A - Grinding wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grinding wheel which grinding a grinding surface of a workpiece such as a wafer without damaging it when grinding, while supplying grinding water to the grinding surface. <P>SOLUTION: Instead of a segment-like grinding wheel, an annular grinding wheel 41 is fixed to a wheel base 43. By radially forming a discharge groove 48 discharging the grinding water to a fixing part 42 fixing the annular grinding wheel 41, the grinding surface of the workpiece is ground without damaging it by a chipped grinding wheel broken piece like the segment-like grinding wheel. Since the grinding water dammed up inside the annular grinding wheel 41 flows out to an external part from the discharge groove 48 radially formed so as to cross with the annular grinding wheel 41, the inside and the outside of the annular grinding wheel 41 are filled with the grinding water, and the annular grinding wheel 41 is sufficiently cooled, and inside grinding chips are discharged. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a grinding wheel mounted on a grinding apparatus including a chuck table that holds a workpiece such as a wafer, and a grinding means that grinds the workpiece held on the chuck table.

  A wafer on which a plurality of devices such as IC and LSI are formed has its back surface ground to a predetermined thickness, and is divided into individual devices by a dividing device such as a dicing device and used for electronic devices such as mobile phones and personal computers. Is done.

  A grinding apparatus for grinding the back surface of a wafer includes a chuck table that holds a wafer, a grinding means that rotatably supports a grinding wheel that grinds the wafer held on the chuck table, and an axis of a rotating spindle that constitutes the grinding means. And a grinding water supply means for supplying the grinding water to the grinding wheel through the passage formed in (1), so that the wafer can be ground efficiently (for example, see Patent Document 1).

  In addition, in the grinding apparatus, in order to make the electronic equipment lighter and smaller, a device region in which a wafer device is formed when the wafer is thinned to a thickness of 50 μm or less and 30 μm or more. In some cases, only the back surface of the wafer is thinly ground, and the ring-shaped reinforcing portion is left in the outer peripheral surplus area surrounding the device area, thereby facilitating the handling of the thinned wafer (for example, see Patent Document 2).

JP 2001-205560 A JP-A-5-121384

  However, in the conventional grinding apparatus disclosed in Patent Document 1 and the like, the grinding wheel has a segmented grinding wheel fixed to the wheel base, and the grinding water is smoothly applied to each segmented grinding wheel. Although supplied, there is a problem in that the grinding surface of the wafer is damaged by the grindstone chips that are missing when the segmented grinding wheel hits the wafer edge. In particular, when the ring-shaped reinforcing portion is left in the outer peripheral surplus region surrounding the device region and the wafer thickness in the device region is reduced to 50 μm or less and 30 μm or more to be mirror finished, the segment shape is used. If the grinding surface of the wafer is damaged by the grinding wheel fragments of the grinding wheel, the cutting surface is damaged, and the mirror finish cannot be realized.

  The present invention has been made in view of the above, and provides a grinding wheel capable of grinding without damaging the grinding surface when grinding while supplying grinding water to the grinding surface of a workpiece such as a wafer. For the purpose.

  In order to solve the above-described problems and achieve the object, a grinding wheel according to the present invention includes a chuck table for holding a workpiece, and a grinding means for grinding the workpiece held on the chuck table; A grinding wheel mounted on a grinding apparatus comprising: an annular grinding wheel; and a wheel base having a fixing portion for fixing the annular grinding wheel, wherein the fixing portion of the wheel base includes The discharge grooves for discharging the grinding water to the outside are formed radially so as to intersect with the annular grinding wheel.

  A grinding wheel according to the present invention is a grinding wheel mounted on a grinding apparatus comprising a chuck table for holding a workpiece and a grinding means for grinding the workpiece held on the chuck table. The grinding means is formed of a mount for supporting the grinding wheel, a spindle for supporting and rotating the mount, a motor for rotationally driving the spindle, an axis of the spindle and an axis of the mount. A grinding water supply unit for supplying grinding water to the passage, and the grinding wheel includes an annular grinding wheel and a wheel base having a fixing part for fixing the annular grinding wheel. The wheel base has an opening for receiving the grinding water supplied from the mount, and the fixed portion receives the annular grinding wheel so as to intersect with the annular grinding wheel. Discharge groove to release the grinding water to the outside which is characterized in that it is formed radially.

  The grinding wheel according to the present invention is characterized in that, in the above invention, the annular grinding stone is any one of a vitrified bond grindstone, a resin bond grindstone, and a metal bond grindstone.

  According to the grinding wheel of the present invention, instead of the segmented grinding wheel, the annular grinding wheel is fixed to the wheel base, and the discharge grooves for discharging the grinding water to the fixing portion to which the annular grinding wheel is fixed are radially provided. The grinding wheel can be ground without damaging the grinding surface of the work piece due to chipped pieces like a segmented grinding wheel, and the grinding wheel can completely overlap the work piece for grinding. Even in this case, the grinding water blocked inside the annular grinding wheel flows out from the discharge grooves formed radially so as to intersect the annular grinding wheel. The outside is filled with grinding water, so that the annular grinding wheel can be sufficiently cooled and the internal grinding waste can be discharged.

  Hereinafter, a grinding wheel mounted on a grinding apparatus which is the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is an external perspective view showing an example of a grinding apparatus to which the grinding wheel of the present embodiment is attached. The grinding apparatus 1 includes a chuck table 3 that holds and rotates a workpiece 2, a grinding means 5 that rotatably supports a grinding wheel 4 that grinds the workpiece 2 held on the chuck table 3, and a grinding means. And a grinding feed means 6 for grinding and feeding 5.

  First, the chuck table 3 is connected to a drive source (not shown) and can rotate. The chuck table 3 is provided so as to be movable in the X-axis direction by a feed mechanism such as a ball screw, a nut, or a pulse motor.

  The grinding means 5 includes a grinding wheel 4, a housing 51, a mount 53 that is rotatably attached to the lower end of the housing 51 and supports the grinding wheel 4 attached by a bolt 52, and a spindle that supports and rotates the mount 53. 54, a motor 55 that rotationally drives the spindle 54, and a moving base 56 on which the housing 51 is mounted. The moving base 56 has a guided rail 561, and the guided means rail 561 is movably fitted to a guide rail 9 provided on the support plate 8 of the housing 7 so that the grinding means 5 can move in the vertical direction (Z It is supported so as to be movable in the axial direction. FIG. 2 is a cross-sectional view showing the structure in the vicinity of the grinding wheel 4 with the cross-sectional positions being different from the center line. As shown in FIG. 2, the grinding means 5 is grinding in which grinding water is supplied from a grinding water supply source (not shown) to passages 54 a and 53 a formed in the axis of the spindle 54 and the axis of the mount 53. A water supply unit 57 is provided. Here, the passage 53a formed in the axial center of the mount 53 is branched into a plurality of passages 53b in the mount 53, and opens to the lower surface side.

  The grinding feed means 6 is for grinding and feeding the grinding wheel 4 in the Z-axis direction by moving the moving base 56 of the grinding means 5 along the guide rail 9. The grinding feed means 6 includes a male screw rod 61 that is disposed on a support plate 8 in a vertical direction parallel to the guide rail 9 and is rotatably supported, a pulse motor 62 for rotationally driving the male screw rod 61, and a moving base. 56 and a female screw block (not shown) that is screwed with the male screw rod 61.

  FIG. 3 is a perspective view showing the grinding wheel 4, and FIG. 4 is an exploded perspective view showing the grinding wheel 4 upside down. The grinding wheel 4 of the present embodiment includes an annular grinding wheel 41 and a wheel base 43 having a fixing portion 42 for fixing the annular grinding wheel 41. The annular grinding wheel 41 is formed in a donut ring shape continuous over the entire circumference by a magnet of extremely fine particles of any of the commonly used vitrified bond grindstone, resin bond grindstone, and metal bond grindstone. By rotating while contacting the grinding surface of the object 2, the grinding surface is polished (ground) to a state close to a mirror surface.

  The wheel base 43 serves as a base material for holding the annular grinding wheel 41, and has a screw hole 44 to be attached to the lower surface of the mount 53 by a bolt 52. The fixed portion 42 has an annular groove 45 that is formed on the lower surface side of the wheel base 43 in a size corresponding to the annular grinding stone 41 and into which the annular grinding stone 41 is fitted. The depth of the annular groove 45 is set so as to protrude by a predetermined amount when the annular grinding stone 41 is fitted and embedded. Further, the wheel base 43 communicates with the grinding water supply unit 57 via the passages 53b, 53a, 54a, so that the grinding water supplied from the mount 53 is received in the base recess 47 to correspond to each passage 53b. A plurality of openings 46 formed so as to penetrate in the thickness direction are provided around the center. Further, the grinding water received from the opening 46 is discharged to the fixed portion 42 of the wheel base 43 to the outside of the wheel base 43 so as to intersect with the annular grinding wheel 41 fixed to the annular groove 45. The discharge grooves 48 are formed radially. In the present embodiment, a plurality of, for example, eight discharge grooves 48 are formed radially at equal intervals so as to be deeper than the annular groove 45 and to divide the annular groove 45.

  FIG. 5 is a perspective view showing a state in which the grinding surface of the workpiece 2 is being ground by the grinding wheel 4. The grinding apparatus 1 according to the present embodiment is provided with a ring-shaped reinforcing portion in the outer peripheral surplus region surrounding the device region, and is thinned so that the thickness of the workpiece in the device region is 50 μm or less and 30 μm or more. An example of application to finishing is shown. For this reason, as shown in FIG. 2, the workpiece 2 to be ground has a device region W1 where a plurality of devices are formed on the surface Wa and an outer peripheral ridge region W2 surrounding the device region W1. The back surface Wb is an object to be polished by the grinding wheel 4. In addition, as shown in FIG. 5, the grinding wheel 4 of the present embodiment is formed smaller than the size of the workpiece 2 to be ground, and the grinding wheel 4 is within the region of the workpiece 2. Always grind with complete overlap.

  The workpiece 2 is in a state where the front surface Wa side is held by the chuck table 3 and the back surface Wb side is exposed. Then, the chuck table 3 is rotated, and the grinding wheel 5 is lowered by the grinding feed means 6 while the grinding wheel 4 is rotated by the motor 55, whereby the annular grinding wheel 41 of the rotating grinding wheel 4 is moved to the workpiece 2. Grinding is performed in contact with the back surface Wb. At this time, the annular grinding wheel 41 is brought into contact with the back side of the device region W1 formed on the surface Wa of the workpiece 2 so that the outer peripheral side thereof is not ground. When the back side of the device region W1 is ground by a predetermined amount, the grinding is finished. Thus, by grinding only the portion corresponding to the device region W1 in the back surface Wb, the concave portion W3 is formed in the back surface Wb, and the portion corresponding to the outer peripheral surplus region W2 has the same thickness as before grinding. The ring-shaped reinforcing portion W4 remains. For example, the width of the ring-shaped reinforcing portion W4 is about 2 to 3 mm, and the thickness is several hundred μm (for example, 700 μm). On the other hand, the thickness of the device region W1 is reduced to about 50 μm or less and about 30 μm or more, and is mirror-finished. During such grinding, the grinding water is supplied from the grinding water supply source to the grinding water supply unit 57, and the grinding wheel 4 supplies the grinding water supplied from the grinding water supply unit 57 into the base recess 47 through the opening 46. accept.

  According to the grinding wheel 4 of the present embodiment as described above, the thickness of the back side of the device region W1 that becomes the grinding surface of the workpiece 2 by the annular grinding wheel 41 is 50 μm instead of the conventional segmented grinding wheel. Hereinafter, since it is thinly polished so as to have a thickness of 30 μm or more, it can be ground without damaging the ground surface of the work piece 2 by a chipped grindstone like a segmented grinding wheel, and the recess W3 (grind surface) is mirror-finished. Can be finished.

  Further, since the grinding wheel 4 always grinds in a state where it completely overlaps the workpiece 2, the grinding water received in the base recess 47 at the opening 46 is blocked inside the annular grinding stone 41. However, since the fixing portion 42 of the wheel base 43 is radially formed with discharge grooves 48 that discharge the grinding water received so as to intersect with the annular grinding stone 41, the annular grinding is performed. The grinding water blocked inside the grindstone 41 overflows the upper part of the annular grinding grindstone 41 and flows out from the discharge groove 48 to the outside, as indicated by arrows in FIG. Thereby, in the recessed part W3 surrounded by the ring-shaped reinforcing part W4, the inside and the outside of the annular grinding stone 41 are filled with the grinding water, and the annular grinding stone 41 is sufficiently cooled. Internal grinding waste can be discharged to the outside.

  In the present embodiment, the ring-shaped reinforcing portion is left in the outer peripheral surplus region surrounding the device region, and the wafer thickness in the device region is reduced to 50 μm or less and 30 μm or more to make a mirror finish. However, the present invention is not limited to such an application example. For example, the present invention can also be applied to a double-head grinding apparatus that performs double-side grinding to remove wafer undulation cut out from an ingot. FIG. 6 shows that the grinding wheels 4A and 4B having the structure as described above are arranged coaxially opposite to each other with the workpiece 2 to be ground interposed therebetween, and a roller or the like is held while holding the workpiece 2 with an appropriate holding mechanism. It is a schematic perspective view which shows the example of application to the double-headed grinding apparatus rotated by the appropriate | suitable rotating mechanism used and grind | polished simultaneously from both surfaces with the grinding wheels 4A and 4B. Even if both sides of the wafer were ground with a double-headed grinding machine using a conventional segmented grinding wheel to remove the undulation of the wafer cut out from the ingot, the undulation could not be removed sufficiently, but the ring grinding When both surfaces were ground simultaneously with the grinding wheels 4A and 4B having the grindstone 41, the undulation of the wafer cut out from the ingot could be removed.

  Furthermore, the grinding wheel 4 shown in the present embodiment, for example, as shown in FIG. 7, the grinding wheel 4 does not completely overlap the workpiece 2 to be ground, but partially overlaps. However, the present invention can also be applied to a normal grinding apparatus that performs grinding.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

It is an external appearance perspective view which shows an example of the grinding device with which the grinding wheel of this Embodiment was mounted | worn. It is sectional drawing which shows the structure of a grinding wheel vicinity, changing a cross-sectional position on the boundary of a centerline. It is a perspective view which shows a grinding wheel. It is a disassembled perspective view which turns over and shows a grinding wheel. It is a perspective view which shows a mode during grinding of the grinding surface of the workpiece by a grinding wheel. It is a schematic perspective view which shows the example of application to a double-head grinding apparatus. It is a schematic perspective view which shows the example of application to a normal grinding apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Grinding device 2 Work piece 3 Chuck table 4, 4A, 4B Grinding wheel 5 Grinding means 41 Annular grinding wheel 42 Fixed part 43 Wheel base 46 Opening part 48 Ejection groove 53 Mount 53a Passage 54 Spindle 54a Passage 55 Motor 57 Grinding Water supply section

Claims (3)

A grinding wheel that is mounted on a grinding device comprising: a chuck table that holds a workpiece; and a grinding means that grinds the workpiece held on the chuck table,
An annular grinding wheel;
A wheel base having a fixing portion for fixing the annular grinding wheel;
With
A grinding wheel characterized in that a discharge groove for discharging grinding water to the outside is formed radially on the fixed portion of the wheel base so as to intersect the annular grinding wheel. A grinding wheel that is mounted on a grinding device comprising: a chuck table that holds a workpiece; and a grinding means that grinds the workpiece held on the chuck table,
The grinding means includes a mount for supporting the grinding wheel, a spindle for supporting and rotating the mount, a motor for rotationally driving the spindle, and a passage formed in the spindle center and the mount axis. A grinding water supply unit to which the grinding water is supplied,
The grinding wheel includes an annular grinding wheel and a wheel base having a fixing portion for fixing the annular grinding wheel,
An opening for receiving grinding water supplied from the mount is formed in the wheel base, and a discharge groove for discharging the grinding water received so as to intersect the annular grinding stone to the outside is formed in the fixed portion. A grinding wheel characterized in that is formed radially.   The grinding wheel according to claim 1 or 2, wherein the annular grinding wheel is any one of a vitrified bond grindstone, a resin bond grindstone, and a metal bond grindstone.

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