JP2017213613A - Dresser board and dressing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably suction and hold a dresser board onto a chuck table.SOLUTION: A dresser board (55), which dresses a cutting blade (42) for cutting workpieces (W), comprises: a dress part (56) having a flat plate shape; and an annular rib part (57) protruding along an outer peripheral edge of the dress part from a rear surface of the dress part. In the structure, rigidity of the dresser board is improved by the annular rib part. Thus, even if only a surface of the dress part is scraped in dressing of the cutting blade, warpage of the dresser board can be inhibited by the annular rib part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a dresser board for dressing the tip of a cutting blade and a dressing method.

  A wafer formed with a device such as an IC or LSI is chamfered on the outer periphery of the wafer in order to prevent cracking and dust generation during the manufacturing process. For this reason, when the wafer is ground until the thickness is reduced, the chamfered portion of the outer periphery of the wafer becomes a knife edge shape (eave shape), and there is a problem that the wafer is broken due to chipping from the outer peripheral side. Therefore, prior to grinding, a technique has been proposed in which a chamfered portion that can become a knife edge is removed by cutting in a circumferential direction with a cutting blade, and then the back surface of the wafer is ground to leave no knife edge. (For example, refer to Patent Document 1).

  Here, if the chamfered portion of the wafer is cut in the circumferential direction with the cutting blade, the wear on one side of the cutting blade tip that contributes to cutting is intense, causing a difference in the amount of wear on both sides of the cutting blade, resulting in uneven wear To do. If uneven wear occurs at the tip of the cutting blade, the cutting accuracy decreases. Therefore, before the uneven wear progresses, a flat dress is formed in which the tip of the cutting blade is shaped flat with a dresser board. In the flat dress, the tip shape of the cutting blade is shaped into a flat shape by relatively moving the dresser board and the cutting blade in a horizontal direction orthogonal to the cutting direction (see, for example, Patent Document 2).

JP 2000-173961 A JP 2013-082021 A

  By the way, the dresser board of Patent Document 2 is sucked and held on a sub chuck table disposed in the vicinity of a wafer chuck table. When only the surface side of the dresser board is cut by the flat dress with the cutting blade, the dresser board tends to warp, and when the warp is severe, the dresser board cannot be sucked and held by the chuck table.

  SUMMARY An advantage of some aspects of the invention is that it provides a dresser board that can be stably sucked and held on a chuck table and a dressing method using the dresser board.

  The dresser board according to the present invention is a dresser board for dressing a cutting blade for cutting a workpiece, and is formed of a flat plate-shaped dress portion and an annular rib projecting to the back surface side along the outer peripheral edge of the dress portion. Part.

  According to this configuration, the annular rib portion protrudes along the outer peripheral edge of the dress portion, and the dresser board is sucked and held by the chuck table so that the annular rib portion is engaged with the outer peripheral side of the chuck table. Since the rigidity of the dresser board is enhanced by the annular rib portion, even when only the surface of the dress portion is scraped by the dress of the cutting blade, the curvature of the dresser board is suppressed by the annular rib portion. Therefore, the dresser board can be stably sucked and held on the chuck table without causing suction failure.

  According to the dressing method of the present invention, the annular rib portion of the dresser board is engaged with the chuck table on the flat holding surface of the chuck table having the same outer diameter as the dress portion of the dresser board. And a dressing step for cutting and dressing the surface of the dresser board placed on the holding surface of the chuck table with a rotating cutting blade. The

  According to the present invention, since the annular rib portion protrudes along the outer peripheral edge of the dress portion, the dresser board can be stably sucked and held on the chuck table.

It is a perspective view of the cutting device of this Embodiment. It is a perspective view of the dresser board of this Embodiment. It is a perspective view of a dresser board and a sub chuck table according to the present embodiment. It is explanatory drawing of the dressing method of this Embodiment. It is a schematic diagram of the dresser board of a modification. It is a schematic diagram of the dresser board of another modification.

  Hereinafter, the cutting apparatus of the present embodiment will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of the cutting apparatus of the present embodiment. Here, the cutting device for edge trimming will be described as an example. However, the cutting device is not limited to the configuration shown in FIG. 1 as long as the dresser board of the present embodiment can be mounted. In FIG. 1, for convenience of explanation, some members are omitted and described, but it is assumed that the configuration normally provided in the cutting apparatus is provided.

  As shown in FIG. 1, the cutting apparatus 1 performs edge trimming with the cutting blade 42 on the outer periphery of the workpiece W held on the chuck table 20, and flattenes the tip of the cutting blade 42 worn by edge trimming with the dresser board 55. Configured to dress. The surface of the workpiece W is divided into a plurality of regions by a grid-like division planned line L, and a device D is formed in each region divided into the division planned lines L. The workpiece W is adhered to the dicing tape T inside the ring frame F, and is carried into the cutting apparatus 1 while being supported by the ring frame F via the dicing tape T.

  In addition, the workpiece W should just be a member used as the cutting object of the cutting apparatus 1, and a material in particular is not limited. The workpiece W may be a semiconductor wafer in which a semiconductor device such as IC or LSI is formed on a semiconductor substrate such as silicon or gallium arsenide, or an optical device such as an LED is formed on an inorganic material substrate such as sapphire or silicon carbide. An optical device wafer may be used. Further, the workpiece W may be a package substrate such as a CSP (Chip Size Package) substrate, a printed circuit board, a metal substrate, or the like, or an adhesive tape such as DAF (Die Attach Film) adhered to the back surface of the wafer. .

  An opening is formed on the upper surface of the base 10 of the cutting apparatus 1 so as to extend in the X-axis direction. This opening is covered with a movable plate 11 and a bellows-shaped waterproof cover 12 that can move together with the chuck table 20. It has been broken. A ball screw type cutting feed mechanism (not shown) for cutting and feeding the chuck table 20 in the X-axis direction is provided below the waterproof cover 12. On the surface of the chuck table 20, a holding surface 21 for holding the workpiece W is formed by a porous porous material. The holding surface 21 is connected to a suction source (not shown) through a flow path in the chuck table 20, and the workpiece W is sucked and held by the negative pressure generated on the holding surface 21.

  An index-feeding mechanism 30 for index-feeding the cutting means 40 in the Y-axis direction and a notch-feed for cutting-feeding each cutting means 40 in the Z-axis direction are provided on the gate-like standing wall portion 13 erected on the upper surface of the base 10 A mechanism 35 is provided. The index feed mechanism 30 has a pair of guide rails 31 arranged in front of the standing wall portion 13 and parallel to the Y-axis direction, and a Y-axis table 32 slidably installed on the pair of guide rails 31. . The cutting feed mechanism 35 has a pair of guide rails 36 arranged on the Y-axis table 32 and parallel to the Z-axis direction, and a Z-axis table 37 slidably installed on the pair of guide rails 36. .

  A cutting means 40 for cutting the workpiece W is provided below the Z-axis table 37. Nuts are formed on the back sides of the Y-axis table 32 and the Z-axis table 37, and ball screws 33 and 38 are screwed to these nuts. Drive motors 34 and 39 are connected to one end of a ball screw 33 for the Y-axis table 32 and a ball screw 38 for the Z-axis table 37, respectively. When the ball screws 33 and 38 are driven to rotate by the drive motors 34 and 39, the cutting means 40 is moved along the guide rail 31 in the Y-axis direction, and along the guide rail 36 in the Z-axis direction. Moved.

  The cutting means 40 is configured by rotatably mounting a cutting blade 42 on the tip of a spindle (not shown) protruding from the housing 41. The cutting blade 42 is formed in a disc shape by bonding (sintering) abrasive grains such as diamond with a bonding agent. The cutting blade 42 may be a hub blade in which a ring-shaped cutting grindstone is fixed to the outer periphery of the hub base, or may be a washer blade constituted by a ring-shaped cutting grindstone. A sub chuck table (chuck table) 50 is provided in the vicinity of the chuck table 20, and a dresser board 55 used for a flat dress at the tip of the cutting blade 42 is sucked and held on the sub chuck table 50. .

  In the cutting apparatus 1 configured as described above, the cutting blade 42 is aligned with the chamfered portion of the outer periphery of the workpiece W, and the surface side of the workpiece W is cut by the cutting blade 42. And the outer peripheral part of the to-be-processed object W is cut over the perimeter by the chuck table 20 making 1 rotation. At this time, since the cutting blade 42 cuts deeper than the finished thickness of the workpiece W in the subsequent grinding process, the workpiece is processed even if the workpiece W is thinned to the finished thickness in the grinding process. The chamfered portion of the outer periphery of W does not remain in a knife edge shape. Therefore, damage due to chipping or the like of the workpiece W after grinding is prevented.

  By the way, at the time of cutting the outer periphery of the workpiece W, the tip of the cutting blade 42 is periodically dressed by the dresser board 55 because the tip shape collapses from the one side that contributed to the cutting of the cutting blade 42. In the flat dress, the tip shape of the cutting blade 42 is adjusted on the surface of the dresser board 55, while a cutting mark 59 (see FIG. 4C) is formed on the surface of the dresser board 55 by the cutting blade 42. For this reason, in the case of a general flat plate-shaped dresser board, the stress balance between the front and back sides of the dresser board is broken and warping occurs, and the dresser board 55 may not be sucked and held by the sub-chuck table 50 in some cases.

  Therefore, an annular rib portion 57 (see FIG. 2) is provided on the outer peripheral edge of the dresser board 55 of the present embodiment so as to increase the rigidity of the dresser board 55. Thereby, even if the surface side of the dresser board 55 is cut by the flat dress, the warp of the dresser board 55 is suppressed by the annular rib portion 57, and the dresser board 55 can be stably sucked and held by the sub chuck table 50. It has become.

  Hereinafter, the dresser board according to the present embodiment will be described with reference to FIGS. FIG. 2 is a perspective view of the dresser board according to the present embodiment. FIG. 3 is a perspective view of the dresser board and sub-chuck table according to the present embodiment.

  As shown in FIG. 2, the dresser board 55 dresses and shapes the tip of the cutting blade 42 (see FIG. 4B), and abrasive grains such as white alundum (WA) and green carbon (GC). Are bonded (sintered) with a bonding agent such as a metal bond, a resin bond, or a vitrified bond. The dresser board 55 has an annular rib portion 57 protruding on the back surface along the outer peripheral edge of the disk-shaped dress portion 56, and the dress portion 56 is reinforced by the annular rib portion 57 to increase the rigidity of the entire board. . Thereby, even if the surface of the dress part 56 is shaved when the cutting blade 42 is dressed, the dresser board 55 is difficult to warp.

  As shown in FIG. 3, the sub-chuck table 50 has an outer diameter smaller than the inner diameter of the annular rib portion 57 of the dresser board 55, and is formed so that the dresser board 55 can be covered from above. The upper surface of the sub-chuck table 50 is a holding surface 51 that holds the dresser board 55 with a porous porous material. The holding surface 51 is connected to a suction source (not shown) through a flow path in the sub chuck table 50, and the dresser board 55 is sucked and held by the negative pressure generated on the holding surface 51. The sub chuck table 50 is connected to a rotation drive mechanism (not shown), and is intermittently rotated by a predetermined angle around the Z axis by the rotation drive mechanism.

  In such a dresser board 55, the dress area 58 for the cutting blade 42 is radially secured on the upper surface of the dressing portion 56, and the dress area 58 is in turn with respect to the cutting blade 42 as the sub chuck table 50 rotates intermittently. Positioned on. Specifically, when a cut mark 59 (see FIG. 4C) is formed in one dress region 58 of the dress portion 56, the sub chuck table 50 is rotated by a predetermined angle, and an uncut portion of the dresser board 55 is cut. Positioned on the blade 42. Cutting marks 59 are radially formed on the surface of the dresser board 55, but warpage of the dresser board 55 is suppressed by the annular rib portion 57, and suction failure does not occur in the sub chuck table 50.

  With reference to FIG. 4, the dressing method of this Embodiment is demonstrated. FIG. 4 is an explanatory diagram of the dressing method of the present embodiment. In addition, it shows an example of the cutting operation shown below, and can be changed as appropriate.

  As shown in FIG. 4A, the placing step is performed before the cutting apparatus 1 (see FIG. 1) is operated. In the placing step, the sub chuck table 50 has the same outer diameter as the dressing portion 56 of the dresser board 55, and the sub rib table 57 is engaged with the outer peripheral surface of the sub chuck table 50. 50 is covered with a dresser board 55. The dresser board 55 is sucked and held by the sub-chuck table 50 by bringing the back side of the dressing portion 56 of the dresser board 55 into contact with the flat holding surface 51 of the sub-chuck table 50. In this way, the dresser board 55 is disposed so as to cover the entire upper portion of the sub chuck table 50.

  As shown in FIG. 4B, a cutting step is performed when the cutting apparatus 1 is operated. In the cutting step, the workpiece W is held on the chuck table 20 so that the center of the workpiece W coincides with the rotation axis of the chuck table 20. The cutting blade 42 is positioned above the chamfered portion on the outer periphery of the workpiece W, and cutting water is sprayed from an injection nozzle (not shown), and the chamfered portion of the workpiece W is cut by the cutting blade 42. Then, the chamfered portion is cut along the outer periphery of the workpiece W by the cutting blade 42 as the chuck table 20 rotates around the Z axis.

  As shown in FIG. 4C, the dressing step is performed when the tip of the cutting blade 42 starts to be unevenly worn in the cutting step. In the dressing step, dressing is performed by cutting the surface of the dresser board 55 placed on the holding surface 51 of the sub-chuck table 50 (see FIG. 3) with the rotating cutting blade 42. In this case, the cutting blade 42 is positioned at the center of the dress portion 56 of the dresser board 55, and the cutting blade 42 slides in the rotational axis direction (Y-axis direction) perpendicular to the cutting direction (X-axis direction) with respect to the dress portion 56. The cutting blade 42 is flat dressed by being moved. Thereby, the tip shape of the cutting blade 42 is adjusted.

  Although cutting water is sprayed when the cutting blade 42 is dressed, the sub chuck table 50 (see FIG. 4B) is completely covered by the dresser board 55, so that the holding surface 51 (see FIG. 3) of the sub chuck table 50 is covered. Cutting water is prevented from entering. When the cutting blade 42 is dressed by the dresser board 55, one cutting mark 59 is formed on the dressing portion 56 in the radial direction. When the cutting trace 59 is formed on the dresser board 55, the sub-chuck table 50 is rotated by a predetermined angle, and an uncut portion of the dresser board 55 is positioned at a dress position where the cutting blade 42 is dressed.

  The dresser board 55 easily warps as the cutting marks 59 on the surface of the dress portion 56 increase. However, since the dresser board 55 is reinforced by the annular rib portion 57, warping of the dresser board 55 in the dress is suppressed. Yes. Therefore, the holding force of the sub chuck table 50 against the dresser board 55 does not decrease. In the dressing step, in order to eliminate clogging of the cutting blade 42, the cutting blade 42 is moved up and down in the cutting direction (Z-axis direction) to cut the dress portion 56, so that the tip of the cutting blade 42 is conspicuously dressed. May be.

  As described above, in the dresser board 55 of the present embodiment, the annular rib portion 57 protrudes along the outer peripheral edge of the dress portion 56, and the annular rib portion 57 is engaged with the outer peripheral side of the chuck table 20. Thus, the dresser board 55 is sucked and held on the chuck table 20. Since the rigidity of the dresser board 55 is enhanced by the annular rib portion 57, even if only the surface of the dress portion 56 is scraped by the dress of the cutting blade 42, warpage of the dresser board 55 is suppressed by the annular rib portion 57. . Therefore, the dresser board 55 can be stably sucked and held on the chuck table 20 without causing a suction failure.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, as shown in the modification of FIG. 5, the dresser board 65 may be formed in consideration of ease of mounting on the sub-chuck table 60, expansion / contraction due to the use environment, and the like. In this case, since the inner diameter of the annular rib portion 67 of the dresser board 65 is formed to be slightly larger than the outer diameter of the sub chuck table 60, the inner peripheral surface of the annular rib portion 67 and the outer peripheral surface of the sub chuck table 60 are arranged. There is a slight clearance between them. For this reason, an annular sealing material 68 such as an O-ring or a V-ring is attached to the outer peripheral surface of the sub-chuck table 60, and the clearance is filled with the sealing material 68.

  Even in such a dresser board 65, since the rigidity is enhanced by the annular rib portion 67, warping of the dresser board 65 is effectively suppressed. In addition, the dresser board 65 can be easily attached to the sub-chuck table 60, and the expansion / contraction of the dresser board 65 can be absorbed by the sealing material 68. Since the clearance is liquid-tightly sealed by the sealing material 68, the cutting water does not reach the holding surface 61 of the sub-chuck table 60 through the clearance, and suction failure does not occur.

  Moreover, in this Embodiment, although the dresser board 55 whole was set as the structure formed by couple | bonding an abrasive grain and a bonding agent, it is not limited to this structure. As shown in the modification of FIG. 6, the dresser board 75 has a flat dress portion 76 fixed to the surface of a resin base material portion 78, and an annular rib portion from the back surface along the outer peripheral edge of the base material portion 78. 77 may be formed so as to protrude. Even with this configuration, it is possible to obtain the same effects as those of the dresser board 55 of the present embodiment.

  Moreover, in this Embodiment, although the dresser board 55 was formed in the top view circular shape, it is not limited to this structure. The dresser board 55 may be formed in a polygonal shape when viewed from above.

  Moreover, in this Embodiment, although the cyclic | annular rib part 57 was set as the structure protruded over the perimeter from the back surface side of the dress part 56, it is not limited to this structure. The annular rib part 57 should just protrude along the outer periphery from the back surface side of the dress part 56, and may protrude partially along the outer periphery from the back surface side of the dress part 56.

  Further, in the present embodiment, the cutting device 1 for edge trimming is illustrated, but the cutting device 1 may be used not only for edge trimming but also for dividing the workpiece W.

  As described above, the present invention has an effect that it can be stably sucked and held on the chuck table, and is particularly useful for a dresser board and a dressing method for dressing a cutting blade for edge trimming.

1 Cutting device 42 Cutting blade 50, 60 Sub chuck table (chuck table)
51, 61 Holding surface 55, 65, 75 Dresser board 56, 66, 76 Dress part 57, 67, 77 Annular rib part W Workpiece

Claims (2)

A dresser board for dressing a cutting blade for cutting a workpiece,
A dresser board formed of a flat dress portion and an annular rib portion formed to protrude toward the back surface along the outer peripheral edge of the dress portion. The dressing portion is formed by engaging the annular rib portion of the dresser board with the chuck table on a flat holding surface of the chuck table having an outer diameter equivalent to the dress portion of the dresser board according to claim 1. A placing step for abutting and holding the back side of the
A dressing method comprising: a dressing step in which a dressing board mounted on the holding surface of the chuck table is cut and dressed with a rotating cutting blade.

Images