JP5254679B2 - Cutting blade dressing method - Google Patents

Description

  The present invention relates to a dressing method for shaping the tip shape of a cutting blade for cutting a workpiece.

  Rectangular substrates such as CSP (Chip Size Package) and QFN (Quad Flat Non-leaded package) in which chips with integrated circuits such as IC and LSI are packaged with resin, and substrates of brittle materials such as glass and sapphire Etc. are divided into individual chips (devices) by cutting along a grid-like street that divides each device, and are widely used for electric devices and electronic parts such as mobile phones and personal computers. .

  The above-described workpiece such as a substrate is usually cut by a cutting device called a dicer. The cutting apparatus includes a chuck table for holding a workpiece on a surface, a cutting means having a rotatable spindle and a cutting blade mounted on the spindle, and a surface of the chuck table that is perpendicular to the central axis direction of the spindle and First moving means for moving the chuck table relative to the spindle in a first direction parallel to the spindle, and moving the spindle relative to the chuck table in a second direction which is the central axis direction of the spindle. And a third moving means for moving the spindle relative to the chuck table in a direction perpendicular to the central axis of the spindle and in a third direction in which the spindle approaches and separates from the chuck table. And moving means. As a cutting blade used in such a cutting apparatus, an electroforming blade in which abrasive grains made of diamond or the like are bonded to a side surface of a base made of aluminum or the like by metal plating such as nickel, abrasive grains made of diamond or the like There are resinoid blades formed by bonding resin with a resin bond to form a donut-like thin plate shape, metal blades obtained by baking and hardening abrasive grains made of diamond or the like with metal bonds, and the thickness is about 50 to 600 μm. The cutting blades formed by joining with the various joining members are appropriately selected and used according to the type of workpiece.

In cutting with a cutting blade, the work piece is fixed to the holding table of the cutting means in a state of being attached to the dicing tape, and the work piece is cut by cutting with the cutting blade to the middle of the attached dicing tape. Is called. As the cutting blade is processed, the bond is consumed, and the abrasive grains that contributed to the cutting fall off, and new abrasive grains are exposed on the surface (self-generated blade), so that good cutting is performed. At the beginning of use, the cutting blade is processed while maintaining a flat shape on the tip surface, and the divided chips are cut vertically from the front surface to the back surface. However, since the cutting blade is consumed from both side corners of the tip, when the workpiece is cut repeatedly, the flat tip surface of the cutting blade gradually changes to a substantially semicircular shape. . When the change in the tip shape becomes excessive, the tip shape of the cutting blade is transferred to the chip after the division, and an undesirable protrusion is generated on the back surface side of the chip (this point will be further described later). For this reason, it is necessary to perform cutting while regularly shaping the tip face shape of the cutting blade into a flat shape. Therefore, as disclosed in the following Patent Documents 1 and 2, it has been proposed to shape the tip of the cutting blade by electric discharge machining.
Japanese Patent Laid-Open No. 2001-54866 JP 2004-114172 A

  However, in the shaping of the cutting blade by electric discharge machining, it is necessary to additionally provide an electric discharge unit, which increases the manufacturing cost of the cutting apparatus. In addition, there is a drawback that it cannot be applied to non-conductive blades such as resin blades.

  The present invention has been made in view of the above-mentioned facts, and the main technical problem thereof can be applied to any blade without providing an additional unit for shaping or the like and not limited to a conductive blade. Another object of the present invention is to provide a new and improved dressing method for a cutting blade which can easily shape the shape of the blade tip surface.

  As a result of diligent research, the present inventors have found that the main technical problem described above can be achieved by adopting a unique dressing mode in which the cutting blade is moved in the direction of the rotation center axis to cut the dresser board. It was.

That is, according to the present invention, as a cutting blade dressing method for achieving the main technical problem, a cutting table having a chuck table for holding a workpiece on a surface, a rotatable spindle, and a cutting blade mounted on the spindle. Means, a first moving means for moving the chuck table relative to the spindle in a first direction perpendicular to the spindle central axis direction and parallel to the surface of the chuck table, and the spindle central axis direction Second moving means for moving the spindle relative to the chuck table in a second direction, and a third direction in which the spindle approaches and separates from the chuck table in a direction perpendicular to the central axis of the spindle. is composed of a third moving means for relatively moving the spindle relative to the chuck table in the direction, Using a cutting device Before moving the chuck table in the direction of the relative said first relative to the spindle by said first moving means when cutting the workpiece held on the surface of the chuck table , A cutting blade dressing method for shaping the tip shape of the cutting blade with a dresser board,
The dresser board holding step for holding the dresser board on the chuck table, and the spindle is rotated and the spindle is moved in the third direction by the third moving means to move the cutting blade to the predetermined cutting position with respect to the dresser board. And a dressing step of moving the spindle in the second direction relative to the chuck table by the second moving means and cutting the dresser board by the cutting blade, Provided.

  In the dressing process, the second moving means moves the spindle in the second direction relative to the chuck table from one end to the other end of the dresser board to cut the dresser board, and then the third moving means. To move the spindle relative to the chuck table in a third direction to increase the cutting depth of the cutting blade with respect to the dresser board, and then the chuck table from the other end of the dresser board to one end by the second moving means. It is preferable to further cut the dresser board by moving the spindle relative to the second direction.

  In the cutting blade dressing method of the present invention, the tip of the cutting blade can be shaped by cutting the dresser board in a unique manner with the cutting blade, so without providing an additional unit for shaping, etc. The shape of the blade tip can be easily shaped. Further, by selecting an appropriate dresser board according to the type of the cutting blade, the present invention can be applied to any cutting blade without being limited to the conductive blade.

  Hereinafter, a preferred embodiment of a dressing method for a cutting blade constructed according to the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 1 shows a main part of a typical example of a cutting apparatus used in the dressing method of the present invention. For the overall configuration of the cutting apparatus, see , for example, the description in JP-A-2003-203885. The cutting apparatus includes a support substrate 2 fixed at a predetermined position. A pair of guide rails 4 extending in the first direction, that is, the X-axis direction are fixed on the support substrate 2, and a sliding block 6 is mounted on the pair of guide rails 4 so as to be movable in the X-axis direction. ing. A screw shaft 8 extending in the X-axis direction is rotatably mounted between the pair of guide rails 4, and an output shaft of a motor 10 constituting the first moving means is connected to the screw shaft 8. The sliding block 6 has a hanging portion (not shown) that hangs downward, and a female screw hole extending through the X-axis direction is formed in the hanging portion, and the screw shaft 8 is screwed into the female screw hole. Are combined. A support table 14 is fixed to the sliding block 6 via a cylindrical member 12 and a chuck means 16 is mounted. Therefore, when the motor 10 rotates in the forward direction, the support table 14 and the chuck means 16 move in the cutting direction indicated by the arrow 18, and when the motor 10 rotates in the reverse direction, the support table 14 and the chuck means 16 move in the return direction indicated by the arrow 20. The chuck table 22 and the pair of gripping means 24 constituting the chuck means 16 are mounted so as to be rotatable about a central axis extending substantially vertically, and the chuck table 22 and the pair of gripping means 24 are disposed in the cylindrical member 12. A motor (not shown) for rotation is provided.

A pair of guide rails 26 extending in the second direction, that is, the Y-axis direction are also fixed to the support substrate 2, and a sliding block 28 is mounted on the pair of guide rails 26 so as to be movable in the Y-axis direction. . A screw shaft 30 extending in the Y-axis direction is rotatably mounted between the pair of guide rails 26, and an output shaft of a motor 32 constituting the second moving means is connected to the screw shaft 30. . The sliding block 28 is substantially L-shaped, and has a horizontal base 34 and an upright portion 36 extending upward from the horizontal base 34. A drooping portion (not shown) that hangs downward is formed in the horizontal base 34, and a female screw hole that extends through in the Y-axis direction is formed in the drooping portion, and a screw shaft 30 is formed in the female screw hole. It is screwed. Therefore, when the motor 32 rotates forward, the sliding block 28 moves in the direction indicated by the arrow 29, and when the motor 32 rotates reversely, the sliding block 28 moves in the direction indicated by the arrow 31.

  A pair of guide rails 38 (only the upper end of one guide rail 38 is shown in FIG. 1) extending in the third direction, that is, the Z-axis direction, are formed on the upright portion 36 of the slide block 28. A pair of guide rails 38 is provided with a connecting block 40 that is movable in the Z-axis direction. A screw shaft (not shown) extending in the Z-axis direction is rotatably mounted on the upright portion 36 of the sliding block 28, and an output shaft of the motor 42 constituting the third moving means is attached to the screw shaft. It is connected. The connecting block 40 is formed with a protruding portion (not shown) protruding toward the upright portion 36 of the sliding block 28. The protruding portion is formed with a female screw hole extending through in the Z-axis direction. The screw shaft extending in the Z-axis direction is screwed into the female screw hole. Therefore, when the motor 42 rotates in the forward direction, the connecting block 40 moves or descends in the direction indicated by the arrow 39, and when the motor 42 rotates in the reverse direction, the connecting block 40 moves or rises in the direction indicated by the arrow 41.

  Referring to FIG. 3 together with FIG. 2, the tip of the spindle 46 in the cutting means 42 protrudes forward from the casing 44, and a cutting blade 48 is attached to the protruding tip. In the illustrated embodiment, the cutting blade 48 is a so-called hubless type having a donut-like thin plate shape with a thickness of about 50 to 600 μm. A flange member 52 is fixed to the tip of the spindle 46 by a fixing nut 55. Further, a cutting blade 48 and an annular flange 54 are mounted on the flange member 52, and a fastening nut 56 is screwed onto a male thread formed at the tip of the flange member 52, and the cutting blade 48 is attached by the fastening nut 56. The annular flange 54 is pressed against the flange member 52. Thus, the cutting blade 48 is sandwiched between the flange member 52 and the annular flange 54 and attached to the spindle 46. FIG. 2 also shows the workpiece W mounted on the frame 58 via the mounting tape 60. The frame 58, which can be formed from a thin metal plate or an appropriate synthetic resin, has a circular opening 62 at the center. The mounting tape 60 is attached to the back surface of the frame 58 and extends across the circular opening 62. The workpiece W is stuck on the upper surface of the mounting tape 60 in the circular opening 62.

  With reference to FIGS. 1 to 3, the cutting manner of the workpiece W in the cutting apparatus as described above will be described. The frame 58 on which the workpiece W is mounted via the mounting tape 60 is placed on the chuck table 14. Arranged and adsorbed onto the chuck table 22 by suction through the chuck table 22 formed from a porous material. In addition, the frame 58 is fixed at a required position by the pair of gripping means 24. The spindle 46 is rotated to rotate the cutting blade 48, and the cutting blade 48 is aligned with the cutting street of the workpiece W. Then, the spindle 46 is lowered to a required position, and more specifically, as shown in FIG. . The sliding block 6 is moved in the direction shown by the arrow 20 (FIG. 1), and the workpiece W is cut along the cutting street. Next, the spindle 46 rises to a position where the cutting blade 48 does not come into contact with the workpiece W, and the drive block 6 returns to the position first cut into the workpiece W in the direction indicated by the arrow 18 (FIG. 1). Indexing movement of the spindle 46 in the Y-axis direction aligns the cutting blade 46 with the next cutting street and moves the activity block 6 in the direction indicated by the arrow 20 (FIG. 1), thus along the next cutting street. To cut the workpiece W. By repeatedly performing such a cutting process and cutting along all the cutting streets extending in parallel in a predetermined direction, the chuck means 16 is rotated by 90 degrees, and then the above cutting is performed. The workpiece W is cut along all the cutting streets extending perpendicularly to the previous cutting street.

  As clearly shown in FIG. 4, the cutting blade 46 is used with its front end surface 64 shaped into a substantially flat shape, and therefore the workpiece W is cut substantially vertically from its front surface to its back surface. Extends straight through its thickness. However, when cutting is performed repeatedly, the cutting blade 46 gradually wears out from the corners on both sides of the tip (more specifically, the abrasive grains that contribute to the cutting are worn out and the new abrasive grains are exposed on the surface). The tip surface of the cutting blade 46 is gradually rounded. If cutting is repeated excessively without performing the shaping dressing of the cutting blade 46, the tip surface of the cutting blade 46 is deformed into a substantially semicircular shape as clearly shown in FIG. When the workpiece W is cut by the deformed cutting blade 46, the shape of the tip surface of the cutting blade 46 is transferred to the cut surface of the workpiece W, and a sharp protrusion is formed at the lower end of the cut surface. 66 is generated. In particular, the thicker the cutting blade 46 is, the larger the semicircular shape becomes, and the protrusion 66 becomes excessive. In order to avoid the occurrence of the protruding portion 66, it is necessary to shape the distal end surface of the cutting blade 46 after repeatedly performing cutting a required number of times.

  According to the present invention, the cutting blade 46 is shaped by dressing the cutting blade in a unique manner of rotating and moving in the direction of its central axis to cut the dresser board.

  A preferred embodiment of the dressing method of the present invention will be described with reference to FIG. 6 together with FIG. 1. When the cutting blade 46 is shaped, a dresser board 68 is held on the chuck table 22 instead of the workpiece W. (Dresser board holding process). Similarly to the workpiece W, the dresser board 68 can be held on the chuck table 22 in a state of being mounted on the frame 58 via the mounting tape 60. If desired, the dresser board 68 can be held on the chuck table 22 alone. As the drain servo 68, one formed of a bond that is harder than the bond of the cutting blade 46 and an abrasive that is larger than the abrasive of the cutting blade 46 is preferably used.

  Next, a dressing process is performed. In this dressing process, the cutting spindle 46 is rotated, and the cutting blade 48 is positioned at a position facing the upper side of the Y-axis direction one end 70 of the dresser board 68. The cutting blade 48 does not need to be positioned with sufficient precision at one end 70 of the dresser board 68, and no particular problem occurs even if the cutting blade 48 is positioned somewhat outward or inward from the one end 70. Next, the spindle 46 is rotated and the motor 42 constituting the third moving means is driven to lower the cutting blade 48 to a height at which the dresser board 68 is cut from the surface by several μm. If the depth of cut is too deep, an excessive load is applied to the cutting blade 48 and there is a risk of breakage. Therefore, it is preferable to cut about 1 to 10 μm. Thereafter, the motor 32 constituting the second moving means is driven to move the cutting blade 48 to the other end 72 of the dresser board 68 in the Y-axis direction (that is, the second direction that is the central axis direction of the spindle 46). Thus, the dresser board 68 is cut by the cutting blade 48. Then, the cutting blade 48 is further lowered by several μm, and the cutting blade 48 is moved in the Y-axis direction from the other end 72 of the dresser board 68 to the one end 70, and thus the cutting of the dresser board 68 is performed by the cutting blade 48. By such cutting, the tip surface 64 of the cutting blade 48 is gradually consumed and shaped from the most protruding portion, that is, the central portion in the width direction. The lowering of the cutting blade 48 and the movement of the cutting blade 48 in the Y-axis direction are repeatedly performed as necessary, and the tip surface of the cutting blade 48 is shaped substantially flat as shown in FIG.

  The preferred embodiment of the dressing method of the cutting blade according to the present invention has been described in detail with reference to the drawings. However, the present invention is not limited to such an embodiment, and various types of the dressing method can be used without departing from the scope of the present invention. Variations and modifications are possible.

The principal part perspective view of the typical example of the cutting device used for the dressing method of this invention. The principal part perspective view of the cutting device which showed the mode in process of the workpiece. FIG. 3 is a cross-sectional view of the workpiece and the vicinity of the cutting blade during cutting the workpiece. Sectional drawing of the cutting blade immediately after use start and after shaping dressing. Sectional drawing of the cutting blade of the state which repeated cutting excessively without performing shaping dressing. The principal part perspective view of the cutting part vicinity at the time of shaping dressing which is this invention.

Explanation of symbols

10: Motor (first moving means)
22: Chuck table 32: Motor (second moving means)
42: Motor (third moving means)
46: Rotating spindle 48: Cutting blade 66: Projection 68: Shaping dresser board 70: Shaping dresser board one end 72: Shaping dresser board other end W: Workpiece

Claims (2)

A chuck table for holding a workpiece on the surface; a cutting means having a rotatable spindle and a cutting blade mounted on the spindle; and perpendicular to the central axis direction of the spindle and parallel to the surface of the chuck table A first moving means for moving the chuck table relative to the spindle in a first direction; and a second direction which is a direction of the central axis of the spindle. A second moving means for moving relative to the chuck table in a direction perpendicular to the central axis of the spindle and in a third direction in which the spindle approaches and separates from the chuck table; is composed of a third moving means for relatively moving the, for cutting the workpiece held on the surface of the chuck table Using a cutting device for moving the chuck table in the direction of the relative said first relative to the spindle by said first moving means in shapes the tip shape of the cutting blade at Dresser board cutting blade Dressing method,
A dresser board holding step of holding the dresser board on the chuck table; and rotating the spindle and moving the spindle in a third direction by the third moving means to move the cutting blade relative to the dresser board. A dressing step of moving the spindle relative to the chuck table in the second direction by the second moving means, and cutting the dresser board by the cutting blade; A cutting blade dressing method comprising:   In the dressing step, the second moving means moves the spindle relative to the chuck table from one end to the other end of the dresser board in the second direction to cut the dresser board. Then, the third moving means moves the spindle relative to the chuck table in a third direction to increase the cutting depth of the cutting blade relative to the dresser board, and then the second 2. The cutting blade dress according to claim 1, wherein the dresser board is further cut by moving the spindle in a second direction relative to the chuck table from the other end to the one end of the dresser board by moving means. Method.

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