JP2016219757A - Method of dividing workpiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for dividing a workpiece that has a low possibility of strongly adhering processing waste to a workpiece.SOLUTION: A workpiece dividing method for dividing a plate-like workpiece (11) in which a device (15) is formed in a region partitioned by a plurality of division plan lines (13) intersecting each other into a plurality of chips, comprises a first cutting step of holding a workpiece using a chuck table (4), cutting a first cutting blade (10a) into the workpiece from exposed one surface (11a) of the workpiece, forming a first cutting groove (17a) having a depth not reaching the other surface (11b) of the workpiece along the division plan line, and a second cutting step of, after performing the first cutting step, holding one surface side of the workpiece using the chuck table, cutting a second cutting blade (10b) into the work piece from the other exposed surface, and forming a second cutting groove (17b) connected to the first cutting groove by removing an uncut portion (19) between the bottom of the first cutting groove and the other surface along the division plan line. The blade thickness of the second cutting blade is made thicker than the blade thickness of the first cutting blade.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a dividing method for dividing a plate-like workpiece into a plurality of chips.

  When dividing a semiconductor wafer, an optical device wafer, a ceramic package substrate, etc. into a plurality of chips, for example, a rotated annular blade is placed on a division planned line (street) set for these workpieces. The workpiece is cut by cutting (for example, see Patent Document 1).

  Before cutting the blade, a tape having a diameter larger than that of the workpiece is attached to the workpiece, and an annular frame surrounding the workpiece is fixed to the outer peripheral portion of the tape. Thereby, the dispersion of the chips formed by cutting the workpiece can be prevented, and the handling property can be maintained.

JP 2012-84720 A

  The above-mentioned tape is usually provided with a glue layer made of a resin having adhesive strength. Therefore, if the blade is cut to a depth that reaches the glue layer of the tape and the workpiece is cut, the processing waste generated from the workpiece will scatter with the resin of the glue layer and adhere strongly to the workpiece. . Such processing dust that adhered strongly could not be easily removed by washing the workpiece.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a method of dividing a work piece that suppresses the possibility that work scraps strongly adhere to the work piece. .

  According to the present invention, there is provided a workpiece dividing method for dividing a plate-like workpiece having a device formed in a region partitioned by a plurality of scheduled division lines intersecting each other into a plurality of chips, the chuck table Hold the work piece with, cut the first cutting blade into the work piece from one side of the exposed work piece, and divide the first cutting groove with a depth that does not reach the other face of the work piece After performing the first cutting step to be formed along a predetermined line and the first cutting step, the one surface side of the workpiece is held by the chuck table, and the exposed other surface is applied to the workpiece. Cutting the second cutting blade, removing the uncut portion between the bottom of the first cutting groove and the other surface along the planned dividing line, and connecting the first cutting groove to the first cutting groove; A second cutting step to form, the second cutting blur Blade thickness of soil, method of dividing a workpiece, characterized in that thicker than blade thickness of the first cutting blade is provided.

  In the present invention, the device is formed on the one surface side of the workpiece, and after the first cutting step is performed, the one surface is protected before the second cutting step is performed. After performing the protective member adhering step for adhering the member and the protective member adhering step, before performing the second cutting step, the one of the workpieces on the chuck table via the protective member A thinning step of holding the surface side and grinding the other exposed surface to thin the workpiece to a predetermined thickness.

  In the method for dividing a workpiece according to the present invention, the first cutting groove having a depth that does not reach the other surface of the workpiece by cutting the first cutting blade from one surface of the workpiece is divided into lines. Then, the second cutting blade is cut from the other surface of the workpiece, and the uncut portion between the bottom of the first cutting groove and the one surface is removed along the planned dividing line. By forming the second cutting groove connected to the first cutting groove, the workpiece is divided into a plurality of chips.

  That is, in the method for dividing a workpiece according to the present invention, the cutting blade is not cut deeper than the thickness of the workpiece, so that even when the tape is applied to the workpiece, the cutting blade is cut into the tape. You don't have to. Therefore, the processing waste does not scatter with a part of the tape and strongly adhere to the workpiece. Thus, according to this invention, the division | segmentation method of the to-be-processed object which restrained the possibility that a process waste will adhere strongly can be provided.

  In the method for dividing a workpiece according to the present invention, the blade thickness of the second cutting blade is larger than the blade thickness of the first cutting blade. The width is wider than the width of the first cutting groove formed by the first cutting blade. Therefore, when removing the uncut portion with the second cutting blade, the region corresponding to the entire bottom of the first cutting groove can be cut, and a part of the bottom of the first cutting groove can be cut through with the second cutting blade. There is no. Thereby, generation | occurrence | production of the chip | tip resulting from a cut-out is suppressed, and the bending strength of a chip | tip can be maintained highly.

It is a perspective view which shows typically the structural example of a to-be-processed object. It is a partial cross section side view which shows a 1st cutting step typically. It is a perspective view which shows a protection member sticking step typically. It is a side view which shows a thinning step typically. It is a partial cross section side view which shows a 2nd cutting step typically.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The workpiece dividing method according to the present embodiment includes a first cutting step (see FIG. 2), a protective member attaching step (see FIG. 3), a thinning step (see FIG. 4), and a second cutting step (FIG. 5). Reference).

  In the first cutting step, a first cutting blade is cut from one surface of the plate-like workpiece into the workpiece, and a first cutting groove having a depth that does not reach the other surface of the workpiece is formed. Form along the planned dividing line. In the protective member attaching step, the protective member is attached to one surface of the workpiece. In the thinning step, the other surface of the workpiece is ground, and the workpiece is thinned to a predetermined thickness.

  In the second cutting step, the second cutting blade is cut into the work piece from the other face of the work piece, and the uncut portion between the bottom of the first cutting groove and the other face is made into the division planned line. A second cutting groove connected to the first cutting groove is formed along the first cutting groove. In the second cutting step, a second cutting blade having a blade thickness larger than that of the first cutting blade in the first cutting step is used.

  In this way, the work piece can be divided into a plurality of chips by forming the first cutting groove and the second cutting groove that penetrate the work piece in the thickness direction along the line to be divided. Hereinafter, the method for dividing the workpiece according to the present embodiment will be described in detail.

  First, the 1st cutting step which forms a 1st cutting groove along the division planned line of a plate-like work piece is carried out. FIG. 1 is a perspective view schematically illustrating a configuration example of a workpiece according to the present embodiment. As shown in FIG. 1, the workpiece 11 is a circular wafer made of a semiconductor material such as silicon, for example, and the surface (one surface) 11a side is a central device region and an outer periphery surrounding the device region. It is divided into surplus areas.

  The device region is further divided into a plurality of regions by a plurality of division lines (streets) 13 that intersect each other, and devices 15 such as ICs and LSIs are formed in each region. In this embodiment, a circular wafer made of a semiconductor material such as silicon is used as the workpiece 11. However, the material, shape, etc. of the workpiece 11 are not limited. For example, a substrate made of a material such as ceramic, resin, or metal can be used as the workpiece 11.

  FIG. 2 is a partial cross-sectional side view schematically showing the first cutting step. The 1st cutting step which concerns on this embodiment is implemented with the cutting device 2 shown in FIG. 2, for example. The cutting device 2 includes a chuck table 4 for holding the workpiece 11.

  The chuck table 4 is connected to a rotation drive source (not shown) including a motor and the like, and rotates around a rotation axis substantially parallel to the vertical direction. A moving mechanism (not shown) is provided below the chuck table 4, and the chuck table 4 is moved in the horizontal direction by the moving mechanism.

  The upper surface of the chuck table 4 is a holding surface 4 a that sucks and holds the surface 11 a side or the back surface (the other surface) 11 b side of the workpiece 11. A negative pressure of a suction source (not shown) acts on the holding surface 4a through a flow path (not shown) formed inside the chuck table 4, and a suction force for sucking the workpiece 11 is generated. To do.

  A first cutting unit 6 a for cutting the workpiece 11 is disposed above the chuck table 4. The first cutting unit 6a includes a first spindle housing (not shown) supported by a first lifting mechanism (not shown). A first spindle 8a connected to a rotational drive source (not shown) including a motor and the like is accommodated in the first spindle housing.

  The first spindle 8a rotates around a rotation axis that is substantially parallel to the horizontal direction by the rotational force transmitted from the rotational drive source, and is lifted and lowered together with the first spindle housing by the first lifting mechanism. An annular first cutting blade 10a is attached to one end of the first spindle 8a exposed to the outside of the first spindle housing.

  In the first cutting step, first, the back surface 11b of the workpiece 11 is brought into contact with the holding surface 4a of the chuck table 4, and the negative pressure of the suction source is applied. Thereby, the workpiece 11 is sucked and held on the chuck table 4 with the surface 11a exposed upward.

  Next, the chuck table 4 and the first cutting unit 6a are relatively moved and rotated to align the first cutting blade 10a with the position corresponding to the division line 13 to be processed. Thereafter, the rotated first cutting blade 10a is lowered to a position where it does not contact the holding surface 4a of the chuck table 4, and the chuck table 4 is moved in a direction parallel to the division line 13 to be processed.

  Thereby, the 1st cutting blade 10a can be cut into the surface 11a side of the to-be-processed object 11, and the 1st cutting groove 17a of the depth which does not reach the back surface 11b can be formed along the division | segmentation scheduled line 13 to be processed. The uncut portion 19 remains between the bottom of the first cutting groove 17a and the back surface 11b of the workpiece 11. When the above procedure is repeated and the first cutting grooves 17a are formed along all the planned division lines 13, the first cutting step ends.

  After the first cutting step, a protective member attaching step for attaching a protective member to the surface 11a of the workpiece 11 is performed. FIG. 3 is a perspective view schematically showing a protective member attaching step. The protective member 21 used in the protective member attaching step is, for example, a tape (film) that is substantially the same shape as the workpiece 11, a resin substrate, a wafer of the same type as or different from the workpiece 11, and the like.

  On the first surface 21 a side of the protective member 21, for example, a glue layer made of a resin having adhesive force is formed. Therefore, the protective member 21 can be attached to the workpiece 11 by bringing the first surface 21 a side of the protective member 21 into contact with the surface 11 a of the workpiece 11. By sticking the protective member 21 to the surface 11a side of the workpiece 11, damage to the device 15 due to a load applied during grinding can be prevented.

  In this protective member attaching step, a tape unit (protective member, film) having a diameter larger than that of the workpiece 11 is attached to the workpiece 11, and a frame unit is configured in which the outer periphery of this tape is fixed to an annular frame. May be. In this case, the workpiece 11 can be easily handled after the second cutting step, which will be described later, as compared with a case where a tape having a diameter similar to that of the workpiece 11 is used.

  After the protective member attaching step, a thinning step for grinding the back surface 11b of the workpiece 11 to a predetermined thickness is performed. FIG. 4 is a side view schematically showing the thinning step. The thinning step is performed by, for example, the grinding apparatus 12 shown in FIG. The grinding device 12 includes a chuck table 14 for holding the workpiece 11.

  The chuck table 14 is connected to a rotation drive source (not shown) including a motor and the like, and rotates around a rotation axis substantially parallel to the vertical direction. Further, a moving mechanism (not shown) is provided below the chuck table 14, and the chuck table 14 is moved in the horizontal direction by this moving mechanism.

  The upper surface of the chuck table 14 is a holding surface 14 a that sucks and holds the second surface 21 b side of the protective member 21 attached to the workpiece 11. A negative pressure of a suction source (not shown) acts on the holding surface 14a through a flow path (not shown) formed in the chuck table 14 to suck the workpiece 11 and the protection member 21. A suction force is generated.

  A grinding unit 16 for grinding the workpiece 11 is disposed above the chuck table 14. The grinding unit 16 includes a spindle housing 18 supported by an elevating mechanism (not shown). Inside the spindle housing 18 is accommodated a spindle 20 connected to a rotational drive source (not shown) including a motor and the like.

  The spindle 20 rotates around a rotation axis substantially parallel to the vertical direction by a rotational force transmitted from a rotational drive source. A disc-shaped wheel mount 22 is fixed to the lower end portion of the spindle 20 exposed to the outside of the spindle housing 18.

  A grinding wheel 24 having substantially the same diameter as the wheel mount 22 is mounted on the lower surface of the wheel mount 22. The grinding wheel 24 includes a wheel base 26 made of a metal material such as stainless steel or aluminum. A plurality of grinding wheels 28 are annularly arranged on the lower surface of the wheel base 26.

  In the thinning step, first, the second surface 21b of the protection member 21 attached to the workpiece 11 is brought into contact with the holding surface 14a of the chuck table 14 to apply a negative pressure of the suction source. Thereby, the workpiece 11 is sucked and held on the chuck table 14 with the back surface 11b side exposed upward.

  Next, the chuck table 14 is moved below the grinding wheel 24. As shown in FIG. 4, the spindle housing 18 is lowered while rotating the chuck table 14 and the grinding wheel 24, respectively. The lowering speed (lowering amount) of the spindle housing 18 is set such that the lower surface of the grinding wheel 28 is pressed against the back surface 11 b of the workpiece 11.

  Thereby, the workpiece 11 can be thinned by grinding the back surface 11b. This thinning step is performed, for example, while measuring the thickness of the workpiece 11. When the workpiece 11 is thinned to a target thickness (predetermined thickness), the thinning step is finished.

  After the thinning step, a second cutting step for removing the uncut portion 19 of the workpiece 11 and forming a second cutting groove connected to the first cutting groove 17a is performed. FIG. 5 is a partial cross-sectional side view schematically showing the second cutting step. The 2nd cutting step which concerns on this embodiment is implemented with the cutting device 2 mentioned above, for example. As shown in FIG. 5, the cutting device 2 includes a second cutting unit 6b different from the first cutting unit 6a.

  The second cutting unit 6b includes a second spindle housing (not shown) supported by a second lifting mechanism (not shown). A second spindle 8b connected to a rotational drive source (not shown) including a motor and the like is accommodated in the second spindle housing. The second spindle 8b rotates around a rotation axis substantially parallel to the horizontal direction by the rotational force transmitted from the rotational drive source, and moves up and down together with the second spindle housing by the second lifting mechanism.

  An annular second cutting blade 10b is attached to one end of the second spindle 8b exposed to the outside of the second spindle housing. The blade thickness of the second cutting blade 10b is larger than the blade thickness of the first cutting blade 10a described above. That is, the width of the second cutting groove formed in the second cutting step is wider than the width of the first cutting groove 17a.

  In the second cutting step, first, the second surface 21b of the protection member 21 attached to the workpiece 11 is brought into contact with the holding surface 4a of the chuck table 4 to apply a negative pressure of the suction source. Thereby, the workpiece 11 is sucked and held by the chuck table 4 with the back surface 11b side exposed upward.

  Next, the chuck table 4 and the second cutting unit 6b are relatively moved and rotated, so that the second cutting blade 10b corresponds to the scheduled division line 13 (first cutting groove 17a, uncut portion 19) to be processed. Align with the position to be. Thereafter, the rotated second cutting blade 10b is lowered to a position slightly lower than the bottom of the first cutting groove 17a, and the chuck table 4 is moved in a direction parallel to the division line 13 to be processed.

  Thereby, the second cutting blade 10b is cut into the back surface 11b side of the workpiece 11, the uncut portion 19 corresponding to the division planned line 13 to be processed is removed, and the second cutting connected to the first cutting groove 17a. A groove 17b can be formed. The workpiece 11 is divided into a plurality of chips corresponding to each device 15 by passing the workpiece 11 in the thickness direction by the second cutting groove 17b and the first cutting groove 17a. When the above procedure is repeated and the second cutting grooves 17b are formed along all the division lines 13 (the first cutting grooves 17a and the uncut portions 19), the second cutting step ends.

  As described above, in the method for dividing a workpiece according to the present embodiment, the first cutting blade 10a is cut from the surface (one surface) 11a of the workpiece 11, and the back surface of the workpiece 11 (the other surface). After the first cutting groove 17a having a depth that does not reach the surface 11b is formed along the planned dividing line 13, the second cutting blade 10b is cut from the back surface of the workpiece 11, and the bottom of the first cutting groove 17a is formed. The uncut portion 19 between the surface 11a and the surface 11a is removed along the planned dividing line 13 to form the second cutting groove 17b connected to the first cutting groove 17a, thereby dividing the workpiece 11 into a plurality of chips. doing.

  That is, in the workpiece dividing method according to the present embodiment, the cutting blade is not cut deeper than the thickness of the workpiece, so that even when a tape (protective member) is applied to the workpiece, the cutting blade It is not necessary to cut into the tape. Therefore, the processing waste does not scatter with a part of the tape and strongly adhere to the workpiece. Thus, according to the present embodiment, it is possible to provide a method of dividing a workpiece that suppresses the possibility that processing scraps adhere strongly.

  Further, in the method for dividing the workpiece according to the present embodiment, the blade thickness of the second cutting blade 10b is made thicker than the blade thickness of the first cutting blade 10a. The width of the two cutting grooves 17b is wider than the width of the first cutting grooves 17a formed by the first cutting blade 10a. Therefore, when removing the uncut portion 19 with the second cutting blade 10b, the region corresponding to the entire bottom of the first cutting groove 17a can be cut (FIG. 5), and the first cutting groove 17a can be cut with the second cutting blade 10b. There will be no breakthrough through the bottom. Thereby, generation | occurrence | production of the chip | tip resulting from a cut-out is suppressed, and the bending strength of a chip | tip can be maintained highly.

  In addition, this invention is not limited to description of the said embodiment, A various change can be implemented. For example, in the said embodiment, after implementing a 1st cutting step, before implementing a 2nd cutting step, after implementing a protective member sticking step, and after implementing a protecting member sticking step, the 2nd cutting Although the thinning step is performed before the step is performed, the protective member attaching step and the thinning step may be performed only when necessary.

  When the protective member attaching step and the thinning step are omitted, a dicing tape attaching step for attaching a dicing tape to the surface 11a of the workpiece 11 is performed before the second cutting step is performed. Is desirable. On the other hand, when the protective member attaching step and the thinning step are performed, the protective member can function as a dicing tape, and therefore the dicing tape attaching step is unnecessary.

  Moreover, in the said embodiment, although the surface 11a side of the workpiece 11 in which the device 15 was formed was cut with the 1st cutting blade 10a, the back surface 11b side was cut with the 2nd cutting blade 10b, The back surface (one surface) side may be cut with a first cutting blade, and the front surface (the other surface) side may be cut with a second cutting blade. In this case, it is desirable to perform a dicing tape attaching step of attaching a dicing tape to the surface of the workpiece before cutting the back side of the workpiece with the first cutting blade.

  Moreover, in the said embodiment, although the 1st cutting step and the 2nd cutting step are implemented using the one cutting device 2 integrally provided with the 1st cutting unit 6a and the 2nd cutting unit 6b, The cutting device used in the cutting step and the cutting device used in the second cutting step may be separated.

  In addition, the structure, method, and the like according to the above-described embodiment can be appropriately modified and implemented without departing from the scope of the object of the present invention.

11 Workpiece 11a Surface (one surface)
11b Back side (the other side)
13 Scheduled line (street)
15 device 17a first cutting groove 17b second cutting groove 19 uncut portion 21 protective member 21a first surface 21b second surface 2 cutting device 4 chuck table 4a holding surface 6a first cutting unit 6b second cutting unit 8a first spindle 8b Second spindle 10a First cutting blade 10b Second cutting blade 12 Grinding device 14 Chuck table 14a Holding surface 16 Grinding unit 18 Spindle housing 20 Spindle 22 Wheel mount 24 Grinding wheel 26 Wheel base 28 Grinding wheel

Claims (2)

A workpiece dividing method for dividing a plate-like workpiece in which a device is formed in an area partitioned by a plurality of division lines intersecting each other into a plurality of chips,
The workpiece is held by the chuck table, the first cutting blade is cut into the workpiece from one surface of the exposed workpiece, and the first cutting groove has a depth that does not reach the other surface of the workpiece. Forming a first cutting step along the line to be divided;
After carrying out the first cutting step, the one side of the workpiece is held by a chuck table, a second cutting blade is cut into the workpiece from the exposed other surface, and the first cutting is performed. A second cutting step of forming a second cutting groove connected to the first cutting groove by removing the uncut portion between the bottom of the groove and the other surface along the line to be divided; and
The method for dividing a workpiece, wherein the blade thickness of the second cutting blade is thicker than the blade thickness of the first cutting blade. The device is formed on the one surface side of the workpiece,
After carrying out the first cutting step and before carrying out the second cutting step, a protective member attaching step for attaching a protective member to the one surface;
After carrying out the protective member attaching step and before carrying out the second cutting step, the one surface side of the workpiece is held by the chuck table via the protective member and the other surface exposed. A thinning step of grinding the workpiece to a predetermined thickness;
The workpiece dividing method according to claim 1, further comprising:

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