JP2013119146A - Cutting tool device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting tool device that does not require the provision of two units of cutting tools of strictly the same weight and has a high degree of freedom for rotation balance adjusting work.SOLUTION: A turning means, that is, a cutting tool device includes: a spindle; a cutting tool wheel disposed at the lowest end of the spindle; a cutting tool unit mounted to the cutting tool wheel; and a balancing weight that offsets the weight of the cutting tool unit which is mounted to the cutting tool wheel at the position of point symmetry with respect to the cutting tool unit with the rotation center of the spindle as a standard while a screw hole into which the thread of the balancing weight for adjusting the rotation balance of the spindle can be screwed in is formed at either the cutting tool unit or the weight for balancing, or both of them.

Description

  The present invention relates to a processing apparatus for cutting a workpiece flatly with a cutting tool having a cutting blade (chip) fixed at the tip.

  A semiconductor wafer having a plurality of semiconductor devices formed on the surface is thinly ground by a grinding apparatus that rotates a grinding wheel called a wheel at high speed and is then divided into individual devices. The divided device electrodes are mounted and mounted by being connected to the mounting substrate electrodes by wires such as wires and solder.

  By pursuing further downsizing of electronic equipment, in recent years, electrodes called semiconductor bumps having a height of 10 to 100 μm are formed on the electrodes of the semiconductor device, and the bumps are directly bonded to the electrodes formed on the mounting substrate. A flip chip type semiconductor chip is developed and put into practical use (see Patent Document 1).

  In this technique, it is important that the bump height is uniform in order to ensure that all electrodes are bonded together. As a countermeasure against this, a technique is known in which a bump upper part is cut with a processing device equipped with a cutting tool and processed into a uniform height (see Patent Document 2).

Japanese Patent Laid-Open No. 2001-7135 JP 2004-319697 A

  However, in a conventional processing apparatus equipped with a cutting tool, since a single cutting tool unit is detachably attached to a wheel base (biting wheel), vibration occurs with the rotation of the cutting tool wheel. There was a problem that the processing quality of the workpiece cut by vibration deteriorated.

  As a method to solve this problem, the rotational balance is adjusted by attaching the exact same bite unit (of course the same weight) at a point-symmetrical position with respect to the axis of rotation of the bite unit used for cutting. However, it has been practiced to suppress vibrations that have occurred with rotation.

  However, in this method, it is necessary to prepare two identical bite units, and the cutting edge of the cutting edge (also referred to as a chip or bite body) at the tip of the bite unit is worn out or the cutting edge is bonded. There was a problem that it was difficult to prepare two of the same weight, such as different amounts of wax.

  The present invention has been made in view of such a point, and the object thereof is not to prepare two bite units having exactly the same weight, and has a high degree of freedom in adjusting the rotation balance. It is to provide a cutting tool.

  The present invention includes a turning table having a chuck table for holding a workpiece and a bite unit for turning the surface of the workpiece held on the chuck table. The turning means is arranged at the spindle and the lower end of the spindle. The bite wheel installed, the bite unit attached to the bite wheel, and having a weight that offsets the weight of the bite unit attached to the bite wheel at a point-symmetrical position with respect to the bite unit with respect to the rotation center of the spindle A cutting tool having a balancing weight, wherein a screw hole into which a spindle screw for adjusting the rotational balance of the spindle can be screwed is formed in either or both of the cutting tool and the balancing weight. A cutting tool for cutting tools is provided.

  According to the present invention, the rotation balance (weight balance) of the spindle can be adjusted by using the weight 66 for balancing the weight appropriately and further adjusting the weight balance with the weight screw when adjusting the rotation balance. There is no need to prepare two bite units having exactly the same weight.

  In addition, by providing screw holes for adjusting the weight of not only the balancing weight but also the cutting tool unit, both the balancing weight and the cutting tool unit can adjust the weight balance with the weight screw and rotate it. When performing the balance adjustment work, the degree of freedom of the adjustment work can be increased.

It is a perspective view of a semiconductor wafer suitable for cutting with the bite wheel of the present invention. It is a perspective view of a cutting tool equipped with a cutting tool wheel of the present invention. It is a perspective view of a bite wheel concerning an embodiment of the present invention. 4A is an exploded perspective view of the bite unit, and FIG. 4B is a perspective view of a balancing weight. FIG. 5A is an exploded perspective view of another type of bite unit, and FIG. 5B is a perspective view of another type of balancing weight. FIG. 6A is a side view showing the attachment structure of the bite unit to the wheel base, and FIG. 6B is a partial sectional front view thereof. FIG. 7A is a side view showing a structure for attaching a balancing weight to the wheel base, and FIG. 7B is a partial sectional front view thereof. It is a schematic diagram which shows the cutting process of the wafer in a bite wheel. FIG. 9A is an enlarged sectional view of the semiconductor wafer before cutting, and FIG. 9B is an enlarged sectional view of the semiconductor wafer after cutting.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, there is shown a perspective view of a semiconductor wafer W suitable for cutting with the bite wheel of the present invention. On the surface of the semiconductor wafer W, the first street S1 and the second street S2 are formed to be orthogonal to each other, and the device is provided in each region partitioned by the first street S1 and the second street S2. A (chip) D is formed.

  As shown in the enlarged view of FIG. 1, a plurality of protruding bumps 5 are formed on the four sides of each device D. These bumps 5 are embedded in the underfill material 7, for example, as shown in the enlarged sectional view of FIG. As the underfill material 7, epoxy resin or benzocyclobutene (BCB) is used.

  Next, with reference to FIG. 2, the cutting tool 2 equipped with the cutting wheel according to the embodiment of the present invention will be described. Reference numeral 4 denotes a base (housing) of the cutting tool 2, and a column 6 is erected on the rear side of the base 4. A pair of guide rails (only one is shown) 8 extending in the vertical direction is fixed to the column 6.

  A cutting tool unit 10 is mounted along the pair of guide rails 8 so as to be movable in the vertical direction. The cutting tool unit 10 is attached to a moving base 12 whose housing 20 moves in the vertical direction along a pair of guide rails 8.

  The cutting tool unit 10 is detachably mounted on a housing 20, a spindle 22 (see FIG. 8) rotatably accommodated in the housing 20, a mount 24 fixed to the tip of the spindle 22, and the mount 24. And a bite wheel 25. A bite unit 26 is detachably attached to the bite wheel 25.

  The cutting tool unit 10 includes a cutting tool feed mechanism 18 including a ball screw 14 and a pulse motor 16 that move the cutting tool unit 10 in the vertical direction along a pair of guide rails 8. When the pulse motor 16 is pulse-driven, the ball screw 14 rotates and the moving base 12 is moved in the vertical direction.

  A chuck table mechanism 28 having a chuck table 30 is disposed at an intermediate portion of the base 4, and the chuck table mechanism 28 is moved in the Y-axis direction by a chuck table moving mechanism (not shown). Reference numeral 33 denotes a bellows, which covers the chuck table moving mechanism.

  In the front portion of the base 4, a first wafer cassette 32, a second wafer cassette 34, a wafer transfer robot 36, a positioning mechanism 38 having a plurality of positioning pins 40, and a wafer carry-in mechanism (loading arm) 42, a wafer unloading mechanism (unloading arm) 44, and a spinner cleaning unit 46 are disposed.

  Further, a cleaning water spray nozzle 48 for cleaning the chuck table 30 is provided at the approximate center of the base 4. The cleaning water spray nozzle 48 sprays cleaning water toward the chuck table 30 in a state where the chuck table 30 is positioned in the wafer loading / unloading area on the front side of the apparatus.

  Referring to FIG. 3, a perspective view of the bite wheel 25 is shown. The bite wheel 25 includes an annular wheel base 50, a bite unit 26 detachably attached to the wheel base 50, and a wheel at a point target position with respect to the bite unit 26 with respect to the rotation center of the wheel base 50. It comprises a bite unit 26 that is detachably attached to the base 50 and a balancing weight 66 that is adjusted to the same weight. The bite wheel 25 is rotated in the direction of the arrow R to cut the bumps 5 (see FIG. 9A) formed on the surface of the wafer W.

  As shown in the exploded perspective view of FIG. 4A, the bite unit 26 includes a substantially rectangular parallelepiped shank (bite shank) 52 and a bite 54 that is detachably attached to the shank 52. The cutting tool 54 has a plate shape, and a cutting blade 56 made of diamond or the like formed in a predetermined shape is fixed to the surface side of one end portion in the longitudinal direction. The bit 54 is formed with a round hole 59 into which a screw 58 is inserted.

  A pit 60 having a depth equivalent to the thickness of the cutting tool 54 is formed on one side surface of the shank 52. A screw hole 61 is formed in the pit 60. The cutting tool 54 is fixed to the shank 52 by inserting the cutting tool 54 into the pit 60 of the shank 52 and screwing the screw 58 into the screw hole 61 through the round hole 59 of the cutting tool 54.

  Furthermore, a screw hole 52a is formed from the upper surface of the shank 52 to the lower side, into which a spindle screw 71 for adjusting the rotation balance can be screwed. In this embodiment, the spindle screw 71 is configured by a so-called potato screw (a screw having the same diameter as the screw head and the screw portion), and a tool such as a hexagonal bar wrench is engaged with the axial end portion. An engaging hole 71a is provided.

  By configuring the weight screw 71 to be able to be screwed to the shank 52 in this way, the weight of the bite unit 26 can be adjusted. The direction in which the screw hole 52a is formed is not particularly limited to the vertical direction as in the present embodiment, and may be any configuration as long as the screw screw 71 that is screwed does not protrude from the surface of the shank 52.

  In this embodiment shown in FIG. 4A, only one spindle screw 71 is used, but a plurality of spindle screws 71 may be inserted into one screw hole 52a. In addition, as the weight screw 71, a screw having an appropriate weight is used when the rotation balance is adjusted.

  As shown in FIGS. 6A and 6B, the wheel base 50 is formed with a rectangular parallelepiped mounting hole 62 and a screw hole 63 that opens to the mounting hole 62. The tool unit 26 is fixed to the wheel base 50 by inserting the shank 52 of the tool unit 26 into the mounting hole 62 formed in the wheel base 50 and screwing the screw 64 into the screw hole 63 and tightening. .

  On the other hand, as shown in FIG. 4B, the balancing weight 66 is set to have the same weight as the bite unit 26, and is used for adjusting the rotational balance of the bite wheel 25 (spindle 22). The balancing weight 66 can be formed by using a member having an arbitrary block shape, for example, by cutting the cutting blade 56 or the cutting tool 54 from the cutting tool 54 in the cutting tool unit 26. A thing close to the weight of the unit 26 can be realized.

  The balancing weight 66 is formed with a screw hole 66a into which a weight screw 72 for adjusting the rotational balance can be screwed downward from the upper surface thereof. In the present embodiment, the spindle screw 72 is constituted by a so-called potato screw (a screw having the same diameter as the screw head and the screw portion), and a tool such as a hexagon wrench is engaged with the axial end portion. An engagement hole 72a that can be formed is provided.

  Thus, by configuring the weight screw 72 to be able to be screwed to the balancing weight 66, the weight of the balancing weight 66 can be adjusted. The direction in which the screw hole 66a is formed is not particularly limited to the vertical direction as in the present embodiment, as long as the screw screw 72 that is screwed does not protrude from the surface of the balancing weight 66. Good.

  In this embodiment shown in FIG. 4B, only one spindle screw 72 is used, but a plurality of spindle screws 72 may be inserted into one screw hole 66a. Further, the weight screw 72 having an appropriate weight is used when the rotation balance is adjusted.

  As shown in FIGS. 3 and 7A and 7B, the balancing weight 66 is formed on the wheel base 50 at a point-symmetrical position with respect to the bite unit 26 with respect to the rotation center of the wheel base 50. Then, the screw 70 is inserted into the mounting hole 68 and screwed into the screw hole 69 and tightened to be fixed to the wheel base 50.

  Further, in addition to the form of the bite unit 26 and the balancing weight 66 shown in FIGS. 4A and 4B, the form of the bite unit 26A and the balancing weight 66A shown in FIGS. 5A and 5B. In this manner, it is also possible to consider a form in which the horizontal screw holes 52b and 66b are formed inward from the side surfaces of the shank 52A and the balancing weight 66A, and the weight screws 71 and 72 are inserted in the horizontal direction. In this case, the position of the center of gravity of the bite wheel 25 can be adjusted by adjusting the position in the depth direction of the screw holes 52b and 66b of the spindle screws 71 and 72, and more precise adjustment is performed in the rotation balance adjustment. It becomes possible.

  In the present embodiment described above, the cutting tool unit 10 (having the chuck table 30 for holding the wafer W, which is the workpiece, and the cutting tool unit 26 for turning the surface of the wafer W held on the chuck table 30 ( The cutting tool 10 includes a spindle 22, a cutting tool wheel 25 disposed at the lower end of the spindle 22, a cutting tool unit 26 attached to the cutting tool wheel 25, and the rotation center of the spindle 22. A cutting tool 2 having a balancing weight 66 attached to the cutting tool wheel 25 at a point symmetrical position with respect to the cutting tool unit 26 and having a weight that offsets the weight of the cutting tool unit 26 is realized.

  Then, a configuration is realized in which screw holes 52a and 66a into which weight screws 71 and 72 for adjusting the rotational balance of the spindle 22 can be screwed are formed in both the bit unit 26 and the balancing weight 66. The rotational balance of the spindle 22 can be adjusted by screwing the screws 71 and 72 into the screw holes 52a and 66a.

  According to the present embodiment described above, the rotation balance (weight) of the spindle 22 is adjusted by appropriately adjusting the balance of the weight by the weight screws 71 and 72, and using the weight 66 for balancing the weight appropriately. Balance) can be adjusted, and it is possible to eliminate the need to prepare two bite units having exactly the same weight.

  In addition, not only the balancing weight 66 but also the bit unit 26 is provided with the screw holes 52a and 66a for adjusting the weight, so that the weight screw 71, The weight balance can be adjusted by 72, and the degree of freedom of the adjustment work can be increased in the adjustment work of the rotation balance.

  This adjustment operation can be performed by removing the bite unit 26 and the balancing weight 66 from the bite wheel 25 and appropriately using weight screws 71 and 72 having appropriate weights.

  In the present embodiment, both the balancing weight 66 and the bite unit 26 are provided with the screw holes 52a and 66a for weight adjustment. However, the present invention is not limited to this example, and the balancing weight 66 and the bite unit 26 are provided. It is also conceivable that a screw hole for adjusting the weight is provided on either one of these.

  Next, a method for cutting the semiconductor wafer W by the bite wheel 25 will be described with reference to FIG. As shown in the enlarged sectional view of FIG. 9A, a plurality of bumps 5 connected to the electrodes of each device D are formed on the surface of the semiconductor wafer W, and these bumps 5 are made of epoxy resin or the like. Embedded in the underfill material 7 formed from

  While rotating the spindle 22 at about 2000 rpm, the bite wheel feed mechanism 18 is driven to cut the cutting blade 56 of the bite unit 26 into the underfill material 7 to a predetermined depth, and the chuck table 30 is 1 mm / s in the arrow Y direction. The bump 5 is cut together with the underfill material 7 while moving at a feed rate of. During this cutting process, the chuck table 30 is processed and fed in the Y-axis direction without rotating.

  When the left end of the wafer W sucked and held by the chuck table 30 passes through the attachment position of the cutting blade 56, the cutting of the wafer W is completed, and the surface of the underfill material 7 becomes flat as shown in FIG. 9B. The bump 5 is cut together with the underfill material 7 so that the height thereof is uniformly processed.

  When the cutting process described above is performed, the rotation balance of the spindle is adjusted by the configuration of the present embodiment, and the vibration associated with the rotation of the bite wheel 25 is reduced, so that the workpiece caused by the vibration is reduced. Deterioration of the processing quality can be suppressed. That is, cutting with high processing accuracy can be realized.

25 Bite wheel 26 Bite unit 52 Shank 52a Screw hole 54 Bite 56 Cutting blade 66 Balancing weight 66a Screw hole 71 Weight screw 72 Weight screw

Claims (1)

A turning table having a chuck table for holding a workpiece and a tool unit for turning the surface of the workpiece held by the chuck table;
The turning means includes a spindle, a bite wheel disposed at a lower end of the spindle, a bite unit attached to the bite wheel, and a point symmetrical position with respect to the bite unit with respect to the rotation center of the spindle. A cutting tool equipped with a balancing weight mounted on the cutting wheel and having a weight that offsets the weight of the cutting tool unit,
A tool cutting machine characterized in that a screw hole into which a spindle screw for adjusting the rotational balance of the spindle can be screwed is formed in one or both of the tool unit and the balancing weight.