JP7620376B2 - How to dress cutting blades - Google Patents

Description

The present invention relates to a cutting blade used in a cutting device.

When manufacturing device chips from a disk-shaped silicon wafer, grinding equipment, cutting equipment, etc. are used. For example, first, devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integration) are formed on the front side of the wafer, and then the back side is thinned using a grinding equipment, and then the wafer is divided into multiple device chips using a cutting equipment.

Cutting devices are also used when dividing a package substrate, in which multiple device chips arranged on a base substrate are covered with a sealing material (molding resin) such as resin, into multiple packages (device packages) such as CSPs (chip size packages) and QFNs (quad flat non-leaded packages).

The cutting device is equipped with a cutting unit that includes a cylindrical spindle. A rotary drive source such as a motor is connected to one end of the spindle, and a blade mount is fixed to the other end of the spindle (see, for example, Patent Document 1). The blade mount has a cylindrical boss portion, and a receiving flange is provided integrally with the boss portion on the outer periphery of the boss portion.

An annular cutting blade is placed on this mount blade. For example, a hubless blade (washer-type blade) is used as the cutting blade, which does not have a base and is entirely made of bond and abrasive grains, functioning as a cutting edge.

When attaching the cutting blade to the spindle, first insert the opening of the cutting blade into the boss. In this state, insert the retaining flange into the boss, and then screw a nut onto the outer periphery of the boss. This causes the cutting blade to be clamped between the receiving flange and the retaining flange in the thickness direction.

The outer diameters of the receiving flange and the pressing flange are approximately the same, and the outer diameter of the cutting blade before use is larger than the outer diameters of the receiving flange and the pressing flange. Therefore, the cutting blade before use protrudes a predetermined length in the radial direction of the cutting blade. The amount of radial protrusion of the cutting blade (i.e., the amount of cutting edge exposure) is set to an optimal value depending on the type and thickness of the cutting blade, etc.

If the cutting edge is too far out, the cutting blade will vibrate in the thickness direction when cutting the workpiece, making the cutting edge more likely to break. Also, if the cutting edge is too far out, the workpiece may be cut in a curved manner (where the cut line is misaligned or curved at the entrance and exit), reducing the quality of the workpiece.

In particular, resin blades have weaker bond strength than electroformed bonds, metal bonds, etc., so it is common to reduce the amount of cutting edge exposure. On the other hand, if the amount of cutting edge exposure is too small, the cutting blade will quickly wear out and become unusable.

JP 2007-258590 A

Normally, when a cutting blade wears down and the amount of cutting edge exposure becomes small, the cutting blade is discarded. Therefore, the amount of cutting edge exposure corresponds to the lifespan of the cutting blade. In contrast, when the amount of cutting edge exposure becomes small, it is possible to extend the lifespan of the cutting blade by replacing the blade mount and the pressing flange with blade mounts and pressing flanges that each have an outer diameter smaller than the outer diameter of the worn cutting blade.

However, additional work such as replacing the blade mount and receiving flange, and preparation work after replacement and before resuming cutting, arises, resulting in a problem of reduced productivity. The present invention was made in consideration of these problems, and aims to provide a cutting blade that is less likely to break even if the cutting edge exposure amount is increased.

According to one aspect of the present invention, there is provided a method for dressing a cutting blade, the method comprising: a holding step of holding a dresser board on a chuck table; and a cutting blade protruding step of cutting a cutting blade into the dresser board, the cutting blade comprising an annular cutting edge portion containing abrasive grains and a resin-bonded binder, the abrasive grains being fixed by the binder, and an annular reinforcing member formed integrally with the cutting edge portion on each of one side of the cutting edge portion and the other side opposite to the one side, for reinforcing the strength of the cutting edge portion, and removing a greater amount of the outer periphery of the reinforcing member compared to the outer periphery of the cutting edge portion, thereby causing a radial end of the cutting edge portion to protrude outward beyond the radial end of the reinforcing member, wherein the reinforcing member of the cutting blade is formed of a metal bond .

The cutting blade according to one aspect of the present invention is a cutting blade that includes abrasive grains and a binder, and has an annular cutting edge portion to which the abrasive grains are fixed with the binder, and an annular reinforcing member for reinforcing the strength of the cutting edge portion is provided integrally with the cutting edge portion on each of one side and the other side located opposite the one side. Therefore, compared to the amount of cutting edge exposure of a cutting blade that does not have a reinforcing member, there is an advantage that the cutting blade is less likely to break even if the amount of cutting edge exposure is increased.

In addition, even if the cutting edge wears down with use, the outer diameter of the reinforcing member can be selectively made smaller than the outer diameter of the cutting edge by applying dressing to the cutting blade, allowing the cutting edge to protrude relative to the reinforcing member.

In this way, even if the cutting edge is extended, the cutting blade is less likely to break. Furthermore, even if the cutting edge wears out, the cutting edge can be made to protrude from the reinforcing member by applying dressing to the cutting blade, thereby extending the life of the cutting blade.

FIG. 1A is a perspective view of one surface of a cutting blade, and FIG. 1B is a perspective view of the other surface of the cutting blade. FIG. 2 is a cross-sectional view of a cutting blade. FIG. FIG. 4A is a view showing a state in which the cutting edge portion is worn, and FIG. 4B is a view showing a state in which the cutting edge portion protrudes from the reinforcing member. FIG. 13 is a diagram showing how a cutting blade is dressed. FIG. 2 is a flow diagram of a method for dressing a cutting blade.

An embodiment of the present invention will be described with reference to the attached drawings. First, the cutting blade 2 will be described with reference to Figs. 1(A) to 2. Fig. 1(A) is a perspective view of one surface side of the cutting blade 2, and Fig. 1(B) is a perspective view of the other surface side of the cutting blade 2. Also, Fig. 2 is a cross-sectional view of the cutting blade 2.

The cutting blade 2 has an annular cutting edge portion 4. The cutting edge portion 4 has one surface 4a and the other surface 4b, which are approximately flat, and an opening 4c. For example, the outer diameter of the cutting edge portion 4 is 58 mm, and the diameter of the opening 4c is 40 mm. In addition, the thickness from the one surface 4a to the other surface 4b is a predetermined value (for example, 0.3 mm) that is 0.02 mm or more and 3.00 mm or less.

The cutting edge portion 4 has abrasive grains 6 such as diamond, cBN (cubic boron nitride), etc., and each abrasive grain 6 is fixed to each other with a bond (binding material) 8 such as a resin bond, electroformed bond, metal bond, etc. In this way, the cutting edge portion 4 is composed only of the abrasive grains 6 and the bond 8. Note that in Figure 2, the size of the abrasive grains 6 is exaggerated for convenience, but the actual abrasive grains 6 have a size on the order of μm.

A first reinforcing member 10a having an annular shape is fixed to one surface 4a of the cutting blade portion 4. Similarly, a second reinforcing member 10b having an annular shape is fixed to the other surface 4b of the cutting blade portion 4. The first reinforcing member 10a has an opening 10c having the same diameter as the opening 4c, and similarly, the second reinforcing member 10b has an opening 10d having the same diameter as the opening 4c.

As shown in FIG. 2, the centers of the diameters of the cutting edge portion 4, the first reinforcing member 10a, and the second reinforcing member 10b are approximately aligned, and the centers of the openings 4c, 10c, and 10d are also approximately aligned.

The thickness of each of the first reinforcing member 10a and the second reinforcing member 10b may be approximately the same as the cutting edge portion 4, or may be thinner or thicker than the cutting edge portion 4. The thickness of each of the first reinforcing member 10a and the second reinforcing member 10b is a predetermined value (e.g., 0.35 mm) that is 0.01 mm or more and 5.00 mm or less.

The first reinforcing member 10a and the second reinforcing member 10b are integrally provided with the cutting edge portion 4 and constitute a reinforcing member 12 for reinforcing the strength of the cutting edge portion 4. The reinforcing member 12 does not have abrasive grains 6 and is formed, for example, from a resin bond (i.e., a sintered resin) used in the cutting blade 2, but may also be formed from a metal bond (i.e., a sintered metal).

When the outer periphery 12a of the first reinforcing member 10a and the outer periphery 12b of the second reinforcing member 10b are each removed by a predetermined amount (e.g., 4 mm) in the radial direction 14, the end 12c of the reinforcing member 12 in the radial direction 14 is positioned inside the end 4d of the cutting edge portion 4 in the radial direction 14. As a result, the cutting edge portion 4 protrudes a predetermined protrusion amount 16 from the reinforcing member 12 in the radial direction 14, and the side of the tip of the cutting edge portion 4 is exposed.

Here, an example of a method for manufacturing a cutting blade 2 in which the cutting edge portion 4 has abrasive grains and a resin bond, and the reinforcing member 12 is formed of a resin bond, is described. First, a plurality of abrasive grains 6 and a thermosetting resin are mixed to form a mixture. Next, the mixture is molded into an annular molded body using a die.

During molding, the mixture is pressed with a predetermined pressure of, for example, 200 kgf/cm ² to 1000 kgf/cm ² , and the mold is heated so that the mixture reaches a predetermined temperature of 100° C. to 300° C.

Next, the molded body is sintered at a temperature of 100°C to 300°C for 20 to 40 hours to form a circular sintered body (i.e., the cutting edge portion 4). After that, sintered bodies of thermosetting resin having approximately the same diameter as the cutting edge portion 4 are placed on one surface 4a and the other surface 4b of the cutting edge portion 4, respectively.

Then, the laminated body consisting of the fired body on one side 4a, the cutting edge portion 4, and the fired body on the other side 4b is pressed with a weight or the like and heat treated at a predetermined temperature (e.g., 180°C) for a predetermined time (e.g., 8 hours). This produces a cutting blade 2 in which the cutting edge portion 4 and the reinforcing member 12 are integrated by thermocompression.

In addition, a laminate may be formed by arranging annular sintered metal bodies having approximately the same diameter as the cutting edge 4 on each of the side 4a and the other side 4b of the cutting edge 4 having the resin bond, and heat-treating the laminate at a predetermined temperature for a predetermined time while being pressed. In this case, reinforcing members 12 formed of metal bond are integrally provided on both sides of the cutting edge 4 having the resin bond.

Similarly, a reinforcing member 12 formed with a resin bond or a reinforcing member 12 formed with a metal bond may be integrally provided on both sides of the cutting edge portion 4 having a metal bond. Also, a reinforcing member 12 formed with a resin bond or a reinforcing member 12 formed with a metal bond may be integrally provided on both sides of the cutting edge portion 4 having an electroformed bond.

The manufacturing method of the cutting blade 2 is not limited to the above example. The pressure, temperature, time, etc. during the heat treatment are appropriately changed depending on the material of the cutting blade 2 and the required characteristics of the cutting blade 2. In addition, in the above description of the manufacturing method, the cutting edge portion 4 and the reinforcing member 12 have approximately the same diameter, but the diameter of the cutting edge portion 4 may be larger than the diameter of the reinforcing member 12.

Next, the cutting unit 20 to which the cutting blade 2 is attached will be described. FIG. 3 is an exploded perspective view of the cutting unit 20. Note that in the following description, the X-axis direction (machining feed direction), Y-axis direction (indexing feed direction), and Z-axis direction (cutting feed direction, height direction) are mutually perpendicular.

The cutting unit 20 has a cylindrical spindle housing 22 with a longitudinal portion in the Y-axis direction. A cylindrical spindle 24 is housed in the spindle housing 22 in a rotatable manner. A rotational drive source such as a motor is connected to one end of the spindle 24.

A blade mount 26 is attached to the other end (tip) of the spindle 24. The blade mount 26 has a cylindrical boss portion 28 on the opposite side to the portion to be attached to the spindle 24. A male thread 30 is formed on the outer periphery of the tip of the boss portion 28.

A receiving flange 32 is provided integrally with the boss portion 28 on the outer periphery of the boss portion 28. The receiving flange 32 has an annular support surface 32a that contacts the first reinforcing member 10a or the second reinforcing member 10b of the cutting blade 2. Note that, although the second reinforcing member 10b contacts the support surface 32a in FIG. 3, the first reinforcing member 10a may contact the support surface 32a.

With the blade mount 26 attached to the tip of the spindle 24, the bolt 34 is inserted into the boss portion 28 and fastened to the spindle 24, and the blade mount 26 is fixed to the spindle 24.

Then, the openings of the cutting blade 2 (i.e., openings 4c, 10c, and 10d) are inserted into the boss portion 28, and then the opening 36a of the annular pressing flange 36 is inserted into the boss portion 28. Then, the annular nut 38 is fastened to the male thread 30, so that the cutting blade 2 is clamped between the receiving flange 32 and the pressing flange 36.

The cutting blade 2 of this embodiment has a cutting edge portion 4 and a reinforcing member 12 that are each integrally provided. Therefore, compared to the amount of cutting edge exposure of a cutting blade consisting of only the cutting edge portion 4, there is an advantage in that the cutting blade 2 is less likely to break even if the amount of cutting edge exposure is increased.

Here, other components of the cutting device (not shown) in which the cutting unit 20 is disposed will be described. A Y-axis/Z-axis movement mechanism (not shown) for moving the cutting unit 20 along the Y-axis and Z-axis directions is connected to the upper part of the cutting unit 20.

A chuck table 40 (see FIG. 5) is disposed below the cutting unit 20. The chuck table 40 has a holding surface (not shown) that suction-holds a workpiece (not shown). A rotational drive source (not shown), such as a motor, is provided below the chuck table 40 to rotate the chuck table 40 around a rotation axis parallel to the Z-axis direction.

The output shaft of the rotary drive source is connected to the bottom of the chuck table 40. A ball screw type X-axis direction movement unit (not shown) is disposed below the rotary drive source. When the X-axis direction movement unit is operated, the chuck table 40 moves along the X-axis direction together with the rotary drive source.

When cutting a workpiece, first, the workpiece is suction-held on the holding surface of the chuck table 40 via a dicing tape (not shown). Next, while rotating the cutting blade 2 at high speed, the lower end of the cutting blade 2 is positioned at a height between the holding surface and the top surface of the workpiece.

Then, by operating the X-axis direction moving unit, the cutting blade 2 and the chuck table 40 are moved relatively along the X-axis direction, and the workpiece is cut. However, as the cutting of the workpiece proceeds, the cutting edge portion 4 may wear down and the protrusion amount 16 may become smaller.

Figure 4 (A) shows the state in which the cutting edge portion 4 is worn. In this case, the cutting blade 2 can be dressed using a dresser board 11 to make the cutting edge portion 4 protrude from the reinforcing member 12.

Figure 4 (B) is a diagram showing the state in which the cutting edge portion 4 protrudes from the reinforcing member 12. Figure 5 is a diagram showing the state in which the cutting blade 2 is dressed, and Figure 6 is a flow diagram of the method for dressing the cutting blade 2.

When dressing the cutting blade 2, first, the dresser board 11 is held by the chuck table 40 (holding step S10). The dresser board 11 is a rectangular plate-shaped member having a thickness of, for example, 3 mm to 5 mm.

The dresser board 11 is made of a mixture of abrasive grains such as white alundum (WA) and green carbon (GC) in a binder such as vitrified or resinoid. The bond and abrasive grains that make up the dresser board 11 may be changed as appropriate depending on the configuration of the cutting blade 2, etc.

The dresser board 11 is integrated with a metal annular frame 19 via adhesive tape 17. Specifically, adhesive tape 17 is attached to one surface of the annular frame 19 so as to cover the opening of the annular frame 19, and adhesive tape 17 is attached to the underside 11b of the dresser board 11 so as to be exposed to the opening.

In the holding step S10, the holding surface of the chuck table 40 suction-holds the side of the adhesive tape 17 opposite the side to which the dresser board 11 is attached. Next, the cutting edge protruding step S20 is performed.

In the cutting edge protruding step S20, the cutting blade 2 is rotated at high speed and the lower end of the cutting blade 2 is positioned at a height between the holding surface of the chuck table 40 and the upper surface 11a of the dresser board 11.

The cutting blade 2 and the chuck table 40 are then moved relative to each other along the X-axis direction to cut the cutting blade 2 into the dresser board 11. The reinforcing member 12 does not have abrasive grains 6, so it is easier to remove than the cutting edge portion 4.

Therefore, the reinforcing member 12 is mainly removed according to the amount of cutting, and the end 4d of the cutting edge portion 4 in the radial direction 14 protrudes outward from the end 12c of the reinforcing member 12 in the radial direction 14. In this way, in the cutting edge portion protruding step S20, the cutting edge portion 4 can be protruded relative to the reinforcing member 12 by removing more of the outer periphery 12a, 12b of the reinforcing member 12 compared to the outer periphery 4e of the cutting edge portion 4.

When the reinforcing member 12 is formed with a resin bond, it is easier to obtain a selectivity ratio for the cutting edge portion 4 in the cutting edge portion protruding step S20 compared to when the reinforcing member 12 is formed with a metal bond. Therefore, from the viewpoint of the selectivity ratio, it is preferable to form the reinforcing member 12 with a resin bond.

In the cutting blade 2 of this embodiment, even if the cutting edge is extended, the cutting blade 2 is less likely to break. Furthermore, even if the cutting edge portion 4 wears, the cutting blade 2 can be dressed to cause the cutting edge portion 4 to protrude relative to the reinforcing member 12, thereby extending the life of the cutting blade 2.

In addition, the structures, methods, etc. according to the above embodiments can be modified as appropriate without departing from the scope of the purpose of the present invention. For example, in the cutting edge protruding step S20, instead of cutting the dresser board 11, dressing can be performed using a dresser board 11 on which a linear groove having a width narrower than the thickness of the cutting blade 2 and approximately corresponding to the thickness of the cutting edge 4, and a predetermined depth, is formed.

Specifically, the lower end of the rotating cutting blade 2 is positioned at a predetermined height, and the cutting blade 2 is passed through the groove of the dresser board 11. This allows only the reinforcing member 12 to be partially removed in the radial direction 14 without removing the cutting edge portion 4.

2: Cutting blade 4: Cutting edge portion, 4a: One surface, 4b: Other surface, 4c: Opening, 4d: End, 4e: Outer periphery 6: Abrasive grain, 8: Bond 10a: First reinforcing member, 10b: Second reinforcing member, 10c, 10d: Opening 11: Dresser board, 11a: Upper surface, 11b: Lower surface 12: Reinforcing member, 12a, 12b: Outer periphery, 12c: End 14: Radial direction 16: Protrusion amount 17: Adhesive tape 19: Annular frame 20: Cutting unit 22: Spindle housing 24: Spindle 26: Blade mount 28: Boss portion 30: Male thread 32: Receiving flange, 32a: Support surface 34: Bolt 36: Pressing flange, 36a: Opening 38: Nut 40: Chuck table

Claims (1)

a holding step of holding the dresser board on a chuck table;
a cutting blade including an annular cutting edge portion containing abrasive grains and a resin bond binder, the abrasive grains being fixed by the binder, and annular reinforcing members provided integrally with the cutting edge portion on each of one side and the other side opposite to the one side for reinforcing the strength of the cutting edge portion, is cut into the dresser board, and a cutting edge portion protruding a radial end portion of the cutting edge portion outward from a radial end portion of the reinforcing member by removing a larger amount of an outer periphery of the reinforcing member compared to an outer periphery of the cutting edge portion;
Equipped with
A method for dressing a cutting blade, wherein the reinforcing member of the cutting blade is formed of a metal bond.

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