JP7451041B2 - hub type cutting blade - Google Patents

Description

The present invention relates to a hub-type cutting blade to which ultrasonic vibrations are applied.

Silicon (Si), silicon carbide (SiC), gallium arsenide (GaAs), gallium nitride (GaN), lithium tantalate (LT), lithium niobate (LN), glass, sapphire, ceramics, etc. When dividing a plate-shaped workpiece made of material into individual device chips, for example, a cutting device is used.

A cutting blade having a cutting edge is attached to the cutting device. The cutting blade has a plurality of abrasive grains and a bond for fixing each abrasive grain to each other. By the way, when a workpiece is cut with a cutting blade, a chip called chipping may occur in the device chip, or the cutting blade may be tilted diagonally with respect to the surface of the workpiece due to cutting resistance.

In order to reduce the number and size of chipping, the inclination of the cutting blade, etc., the processing conditions when processing the workpiece are adjusted. For example, machining conditions are adjusted by changing the type of abrasive grain or bond, changing the machining speed, or vibrating the cutting blade at an ultrasonic frequency.

The cutting blade has a hubless (washer) type cutting blade consisting of an annular cutting edge, and one annular surface of the cutting blade is fixed with adhesive to the annular surface of an annular base (hub) to connect the cutting blade and the annular shape. There is a hub-shaped cutting blade that is integrated with the base. When a cutting blade is vibrated in the radial direction at an ultrasonic frequency, a hub-shaped cutting blade that is relatively easy to vibrate is used in order to reliably apply ultrasonic waves to the cutting blade.

However, in a hub-type cutting blade, if the cutting edge is made of abrasive grains of #800 or more (i.e., relatively small size), if the cutting blade is made of abrasive grains of less than #800 (i.e., relatively large size), Compared to the case where the cutting blade is made of abrasive grains, the unevenness on one annular surface of the cutting blade is reduced. In addition, in the display of particle size, the larger the number following #, the smaller the maximum particle diameter of the abrasive grain, and the smaller the number following #, the larger the maximum particle diameter of the abrasive grain.

When the unevenness on one side of the annular shape of the cutting blade is reduced (that is, the protrusion amount of abrasive grains on one side of the annular shape is reduced), adhesive is applied to one side of the cutting blade and the annular shape of the annular base is If the annular base and the cutting blade are pressed so that the surfaces approach each other, the adhesive will escape from the gap between the one surface and the annular surface. Therefore, the amount of adhesive necessary for fixation may not remain between the cutting blade and the annular base.

Japanese Patent Application Publication No. 2007-73586

If the required amount of adhesive is not filled between the cutting blade and the annular base, the cutting blade and the annular base will not be sufficiently fixed, and the cutting blade will not vibrate sufficiently even if the annular base is vibrated. There is a risk that the cutting blade may separate from the base during cutting.

The present invention has been made in view of the above problems, and an object of the present invention is to sufficiently fix the base and the cutting blade in a hub-type cutting blade regardless of the size of the abrasive grains.

According to one aspect of the present invention, the workpiece is a hub-type cutting blade, and the workpiece is held on a chuck table while ultrasonic vibration is applied to the cutting blade attached to the spindle via the blade mount. The cutting blade, which is used in a cutting device for cutting, has an annular cutting blade having abrasive grains fixed with a bond, a through opening that fits into the central boss part of the blade mount, and a hole on the outer peripheral side of the through opening. an annular surface provided on the cutting blade and fixed to a part of the annular surface of the cutting blade with an adhesive, and a recess is provided in the annular surface of the annular base. A recess in which the adhesive is accommodated is provided in a region of the cutting blade corresponding to the annular surface, and a layer of the adhesive is formed in the recess of the cutting blade. A hub-type cutting blade is provided.

Preferably, the recess is a plurality of slits provided in the cutting blade radially from the inner periphery to the outer periphery of the cutting blade, or discretely provided in the cutting blade along the circumferential direction of the cutting blade. It has multiple slits.

Preferably, the hub-shaped cutting blade further includes an annular presser base, and the annular surface of the presser base that contacts the cutting blade does not have a recess, and the presser base and the annular base are holding the cutting blade.

A hub-type cutting blade according to one aspect of the present invention includes an annular cutting blade having abrasive grains fixed with a bond, and an annular base. The annular base includes a through opening that fits into the central boss portion of the blade mount, and an annular surface that is provided on the outer peripheral side of the through opening and is fixed to a part of the annular surface of the cutting blade with adhesive. have

Further, at least one of the annular surface of the annular base and the region of the cutting blade corresponding to the annular surface is provided with a recess in which the adhesive is accommodated, and the recess is provided with a layer of adhesive. is formed. The layer of adhesive formed in the recess ensures a sufficient amount of adhesive to fix the annular base and the cutting blade. Therefore, the cutting blade can be sufficiently vibrated at the ultrasonic frequency, and the cutting blade can be prevented from peeling off from the annular base.

It is a perspective view of a cutting device. FIG. 3 is an exploded perspective view of the cutting unit. FIG. 3 is a partially cross-sectional side view of the cutting unit and the like. FIG. 4(A) is a diagram showing how the cutting blade is assembled, and FIG. 4(B) is a sectional view of the cutting blade after assembly. FIG. 5(A) is an enlarged sectional view of a recessed portion according to the first embodiment, and FIG. 5(B) is an enlarged sectional view of a cutting blade according to a comparative example. FIG. 6(A) is a front view of the annular base according to the first modification, and FIG. 6(B) is a front view of the annular base according to the second modification. FIG. 7(A) is a front view of a cutting blade according to a third modification, and FIG. 7(B) is a front view of a cutting blade according to a fourth modification. FIG. 7 is a partially cross-sectional side view of a cutting blade and the like according to a second embodiment.

Embodiments according to one aspect of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of the cutting device 2. FIG. Note that the X-axis direction (processing feed direction), Y-axis direction (indexing feed direction), and Z-axis direction (vertical direction, cutting feed direction) used in the following description are perpendicular to each other.

The cutting device 2 includes a base 4 that supports each component. An opening 4a is formed in the front corner of the base 4, and a cassette elevator 6 that is raised and lowered by a lifting mechanism (not shown) is provided within the opening 4a.

A cassette 8 is placed on the upper surface of the cassette elevator 6. For convenience of explanation, only the outline of the cassette 8 is shown in FIG. A plurality of workpieces 11 are accommodated in the cassette 8 . Each of the workpieces 11 is housed in the cassette 8 in the form of a workpiece unit 21 supported by a metal annular frame 13 via a resin dicing tape 15 .

A rectangular opening 4b having a longitudinal portion in the X-axis direction is formed on the side of the opening 4a. A ball screw type X-axis moving mechanism (processing feed mechanism) 10 is arranged within the opening 4b. The upper part of the X-axis moving mechanism 10 is covered with a table cover 10a.

A bellows-shaped cover 12 is arranged on each of both sides of the table cover 10a in the X-axis direction. A chuck table 14 for sucking and holding the workpiece 11 is arranged on the table cover 10a. A rotational drive source (not shown) such as a motor is arranged below the table cover 10a.

The lower part of the chuck table 14 is connected to an output shaft of a rotational drive source, and the chuck table 14 is rotatable around a rotation axis that is generally parallel to the Z-axis direction. The chuck table 14, table cover 10a, and rotational drive source are movable in the X-axis direction by the X-axis moving mechanism 10.

A disk-shaped porous plate made of a porous material is provided on the top of the chuck table 14. The porous plate is connected to a suction source (not shown) via a suction path (not shown) formed inside the chuck table 14.

When the suction source is operated, negative pressure acts on the upper surface of the porous plate. Therefore, the upper surface of the chuck table 14 functions as a holding surface 14a for sucking and holding the workpiece 11. Note that four clamps 16 are provided around the chuck table 14 for fixing the annular frame 13 from all sides.

A transport unit (not shown) for transporting the workpiece unit 21 to the chuck table 14 or the like is arranged above the opening 4b. The workpiece unit 21 transported by the transport unit is placed on the holding surface 14a, for example, in such a manner that the surface of the workpiece 11 is exposed upward.

A cantilever-shaped support structure 20 for supporting the cutting unit 18 that cuts the workpiece 11 is arranged on the side of the opening 4b. A cutting unit moving mechanism (index feed mechanism, cut feed mechanism) 22 that moves the cutting unit 18 in the Y-axis and Z-axis directions is provided on the upper surface of the support structure 20.

The cutting unit moving mechanism 22 includes a pair of Y-axis guide rails 24 that are fixed to the surface of the support structure 20 and are generally parallel to the Y-axis direction. A Y-axis moving plate 26 is slidably attached to the Y-axis guide rail 24.

A nut part (not shown) is provided on the back side of the Y-axis moving plate 26 (on the Y-axis guide rail 24 side), and this nut part has a Y-axis ball screw 28 that is generally parallel to the Y-axis guide rail 24. are rotatably connected.

A Y-axis pulse motor (not shown) is connected to one end of the Y-axis ball screw 28, and when the Y-axis pulse motor rotates the Y-axis ball screw 28, the Y-axis moving plate 26 moves to the Y-axis guide rail. 24.

A pair of Z-axis guide rails 30 that are generally parallel to the Z-axis direction are fixed to the surface of the Y-axis moving plate 26. A Z-axis moving plate 32 is slidably attached to the Z-axis guide rail 30.

A nut portion (not shown) is provided on the back side of the Z-axis moving plate 32 (Z-axis guide rail 30 side), and a Z-axis ball screw 34 parallel to the Z-axis guide rail 30 is inserted into this nut portion. They are rotatably connected.

A Z-axis pulse motor 36 is connected to one end of the Z-axis ball screw 34, and when the Z-axis pulse motor 36 rotates the Z-axis ball screw 34, the Z-axis moving plate 32 is moved to the Z-axis guide rail 30. move along.

A cylindrical spindle housing 38 (see FIG. 2) constituting the cutting unit 18 is fixed to the lower part of the Z-axis moving plate 32. Here, the structure of the cutting unit 18 will be explained with reference to FIGS. 2 and 3.

FIG. 2 is an exploded perspective view of the cutting unit 18, and FIG. 3 is a partially sectional side view of the cutting unit 18 and the like. The spindle housing 38 includes a housing body 40 having a substantially rectangular parallelepiped shape. A portion of a substantially cylindrical spindle 40a is rotatably accommodated inside the housing body 40.

The tip of the spindle 40a projects outward from the housing body 40. An opening 40b is formed at the tip of the spindle 40a, and a thread groove is formed on the inner wall of this opening 40b. A motor (not shown) is connected to the base end of the spindle 40a.

A cylindrical housing cover 42 is fixed to the tip of the housing body 40. A through opening 42a is formed in the center of the housing cover 42, and a locking part 42b is provided on the outer circumference of the housing cover 42.

A screw hole 42c is formed in the locking portion 42b. The housing cover 42 is fixed to the housing body 40 by fastening the screw 44 (see FIG. 3) into the screw hole 42c with the tip of the spindle 40a inserted into the through opening 42a.

After the housing cover 42 is fixed to the housing body 40, a substantially cylindrical blade mount (i.e., hub mount) 46 is attached to the tip of the spindle 40a. The blade mount 46 has an annular flange portion 48 provided so as to protrude outward in the radial direction.

A substantially flat annular surface 48a that contacts the cutting blade 60 is formed on the front surface side of the flange portion 48. A first boss portion (center boss portion) 50 is formed at the center of the blade mount 46 so as to protrude beyond the annular surface 48a. Further, a second boss portion 52 is formed on the opposite side of the first boss portion 50 with respect to the flange portion 48 .

A through opening 46a is formed near the central axis of the blade mount 46, passing through the first boss portion 50, the flange portion 48, and the second boss portion 52. The tip of the spindle 40a fits into the inside of the through opening 46a on the second boss portion 52 side.

A step portion for receiving the washer 56 is formed in an annular shape on the first boss portion 50 side of the through opening 46a (see FIG. 3). The blade mount 46 is fixed to the spindle 40a by arranging the washer 56 at the step and fastening the bolt 58 to the opening 40b of the spindle 40a via the washer 56.

A substantially disk-shaped hub-shaped cutting blade 60 is disposed on the outer circumference of the first boss portion 50 . Here, the cutting blade 60 used in the cutting device 2 will be explained with reference to FIGS. 2 and 3. The cutting blade 60 has an annular base 62 made of metal such as an aluminum alloy.

The annular base 62 has an annular center portion 62a. A through opening 60a having substantially the same diameter as the outer circumferential surface 50a of the first boss portion 50 is formed near the central axis of the central portion 62a. An annular flange portion 62b, which is thinner than the center portion 62a, is provided on the outer peripheral side of the through opening 60a so as to surround the center portion 62a.

The flange portion 62b has an annular surface 62c in contact with the annular cutting blade 64. On the inner peripheral side of the annular surface 62c according to the first embodiment, an annular recess 62d is continuously provided along the circumferential direction of the flange portion 62b. The recess 62d is a space for accommodating the adhesive 66.

With the adhesive 66 applied to the inner circumferential side of one surface 64a of the cutting blade 64, when the one surface 64a is pressed against the annular surface 62c and the one surface 64a side is brought into contact with the annular surface 62c, the adhesive 66 is applied to the annular surface 62c and the recess 62d, respectively. A layer of adhesive 66 is formed (see FIGS. 4A, 4B, and 5A). The cutting blade 64 is fixed to the annular surface 62c by a layer of adhesive 66.

An annular presser base 68 is attached to the outer periphery of the center portion 62a of the annular base 62. The presser base 68 has a substantially flat annular surface 68a that holds the cutting blade 64 together with an annular surface 62c of the flange portion 62b.

An annular recess 68b is continuously provided along the circumferential direction of the presser base 68 on the inner peripheral side of the annular surface 68a according to the first embodiment. The recess 68b is a space for accommodating the adhesive 66.

With the adhesive 66 applied to the inner circumferential side of the other surface 64b of the cutting blade 64, when the annular surface 68a is pressed against the other surface 64b and the other surface 64b is brought into contact with the annular surface 68a, the annular surface 68a and the recessed portion are removed. A layer of adhesive 66 is formed on each layer 68b (see FIGS. 4(A) and 4(B)). The cutting blade 64 is fixed to the annular surface 68a by a layer of adhesive 66.

The cutting blade 64 is formed by fixing a plurality of abrasive grains 64c made of diamond, cBN (cubic boron nitride), etc. with a bond 64d made of metal, resin, etc. (see FIG. 5(A), etc.). . The cutting blade 60 is formed by holding the cutting blade 64 between the annular base 62 and the presser base 68.

FIG. 4(A) is a diagram showing how the cutting blade 60 is assembled, and FIG. 4(B) is a sectional view of the cutting blade 60 after assembly. FIG. 5(A) is an enlarged sectional view of the recess 62d of the flange portion 62b according to the first embodiment.

In FIG. 5A, the distance between the one surface 64a and the annular surface 62c is defined by the abrasive grains 64c located on the one surface 64a side being in contact with the annular surface 62c. In this embodiment, the layer of adhesive 66 formed in the recess 62d can ensure a sufficient amount of adhesive 66 to fix the annular base 62 and the cutting blade 64. Therefore, the amount of adhesive 66 can be secured regardless of the size of the abrasive grains 64c.

FIG. 5(B) is an enlarged cross-sectional view of a cutting blade 60 according to a comparative example. The recessed portion 62d is not formed in the flange portion 62b of the comparative example. Therefore, when the abrasive grains 64c located on the side of the one surface 64a come into contact with the annular surface 62c, the distance between the one surface 64a and the annular surface 62c is defined by the amount of protrusion of the abrasive grains 64c.

As a result, the space between the one surface 64a and the annular surface 62c becomes narrow, and the adhesive 66 escapes from the gap between the one surface 64a and the annular surface 62c. Therefore, when the flange portion 62b according to the comparative example is adopted, the amount of adhesive 66 necessary for fixing the cutting blade 64 and the annular base 62 does not remain between the cutting blade 64 and the annular base 62. There are cases.

Referring again to FIG. 3, the cutting blade 60 and the like according to this embodiment will be described. With the through opening 60a of the cutting blade 60 fitted into the first boss part 50 of the blade mount 46, and with the back side of the central part 62a in contact with the annular surface 48a, the first boss part 50 is , an annular mount nut 70 is disposed.

The inner wall surface of the through opening 70a of the mount nut 70 is formed with a female thread that engages with a male thread formed on the outer peripheral surface 50a. When the mount nut 70 is fastened to the outer peripheral surface 50a, the cutting blade 60 is held between the mount nut 70 and the blade mount 46, and is attached to the spindle 40a via the blade mount 46.

Next, an ultrasonic vibration generation mechanism that vibrates the cutting blade 60 in the radial direction will be explained. An annular ultrasonic transducer 72 is arranged on the back side of the central portion 62a of the annular base 62 so as to surround the central axis of the central portion 62a.

The ultrasonic transducer 72 has an annular piezoelectric body. The piezoelectric body is made of materials such as barium titanate (BaTiO ₃ ), lead zirconate titanate (Pb(Zr,Ti)O ₃ ), lithium niobate (LiNbO ₃ ), and lithium tantalate (LiTaO ₃ ). There is.

A first electrode made of metal is provided on one surface of the annular piezoelectric body, and a second electrode made of metal is provided on the other surface of the piezoelectric body. That is, the first electrode and the second electrode are arranged to sandwich the piezoelectric body in the thickness direction of the piezoelectric body.

When the cutting blade 60 is attached to the blade mount 46, the first electrode is connected to a first power supply terminal 74a disposed on a part of the annular surface 48a in the circumferential direction, and the second electrode is connected to a part of the annular surface 48a in the circumferential direction. It is connected to a second power supply terminal 74b arranged at another part in the circumferential direction.

For example, when the first electrode is placed on the blade mount 46 side, by overlapping a part of the second electrode on the first electrode side via an insulator (not shown), a part of the second electrode can be removed. can be placed on the blade mount 46 side.

The first power supply terminal 74a is connected to one end of a first coil 78 disposed on the back side of the flange portion 48 via a first wiring 76a provided on the flange portion 48. Similarly, the second power supply terminal 74b is connected to the other end of the first coil 78 via a second wiring 76b provided on the flange portion 48.

The first coil 78 is wound along the circumferential direction of the flange portion 48 . The tip of the housing cover 42 faces the back side of the flange portion 48 with a small space interposed therebetween. A second coil 80 that constitutes a rotary transformer together with the first coil 78 is provided at the tip of the housing cover 42 .

The second coil 80 is wound along the circumferential direction of the through opening 42a. An AC power source 82 is connected to the second coil 80 via wiring. The AC power supply 82 is composed of a power supply device whose voltage peak value and voltage frequency can be adjusted.

The voltage value and frequency of the AC voltage are adjusted as appropriate depending on the type of cutting blade 64, the type of workpiece 11 (material, size, weight, etc.), and the like. The voltage value of the AC voltage is adjusted, for example, in a range of 10 V or more and 100 V or less, and the frequency of the AC voltage is adjusted, for example, in a range of 20 kHz or more and 500 kHz or less.

When the AC voltage applied to the second coil 80 from the AC power source 82 is supplied to the ultrasonic vibrator 72 via the first coil 78 and the like, the piezoelectric body vibrates in the radial direction. As a result, the cutting blade 64 vibrates in the radial direction of the cutting blade 64 together with the annular base 62 .

As described above, in this embodiment, a sufficient amount of adhesive 66 is secured to fix the annular base 62 and the cutting blade 64, so the cutting blade 60 is sufficiently vibrated at the ultrasonic frequency. be able to. Furthermore, the cutting blade 64 can be prevented from peeling off from the annular base 62.

When cutting the workpiece 11 using the cutting device 2, first, the back side of the workpiece 11 is held by suction with the holding surface 14a. Next, the orientation of the workpiece 11 is adjusted so that the planned dividing line of the workpiece 11 is approximately parallel to the X-axis direction.

Then, the chuck table 14 is arranged so that the cutting blade 60 is located on the extension line of the scheduled dividing line, and the height of the lower end of the cutting blade 60 rotated at high speed is adjusted. Next, while applying ultrasonic vibration to the cutting blade 60, the cutting blade 60 and the chuck table 14 are relatively moved along the X-axis direction. Thereby, the workpiece 11 is cut along the path of relative movement.

Now, returning to FIG. 1, other components of the cutting device 2 will be explained. An imaging unit 84 is provided on the side of the housing body 40 to take an image of the workpiece 11 held by the chuck table 14 under suction.

The imaging unit 84 includes an imaging device (not shown) such as an image sensor, and a condensing lens for condensing light reflected from the workpiece 11 onto the imaging device. A circular opening 4c is formed at a position opposite to the opening 4a with respect to the opening 4b.

A cleaning unit 86 for cleaning the workpiece 11 and the like after cutting is provided in the opening 4c. The workpiece 11 cleaned by the cleaning unit 86 is stored in the cassette 8 using the above-mentioned transport unit or the like.

In this embodiment, the layer of adhesive 66 formed in the recess 62d provides enough adhesive to fix the annular base 62 and the cutting blade 64 even if the size of the abrasive grains 64c is relatively small. 66 can be secured. Therefore, the cutting blade 60 can be sufficiently vibrated at the ultrasonic frequency, and furthermore, the cutting blade 64 can be prevented from peeling off from the annular base 62.

Next, a first modification of the flange portion 62b will be described. FIG. 6(A) is a front view of an annular base 62 according to the first modification. The annular surface 62c of the first modification has an outer portion and an inner portion that are each arranged concentrically. An annular recess 62d is continuously provided between the outer portion and the inner portion along the circumferential direction of the annular surface 62c.

Next, a second modification of the flange portion 62b will be described. FIG. 6(B) is a front view of an annular base 62 according to a second modification. In the flange portion 62b according to the second modification, recesses 62d are provided discretely in the circumferential direction of the annular surface 62c. Specifically, a plurality of additional support surfaces 62e are provided so as to connect the outer and inner portions of the annular surface 62c at each position where the annular surface 62c is divided into eight equal parts in the circumferential direction.

However, the recess 62d does not necessarily have to be divided into eight equal parts in the circumferential direction of the annular surface 62c, and may be divided into any number of parts. Furthermore, the longitudinal direction of the additional support surface 62e does not necessarily have to be parallel to the radial direction of the annular surface 62c. Further, the shapes of the first and second modified examples may also be applied to the recessed portion 68b of the presser foot base 68.

By the way, in the first embodiment and the first and second modified examples, the recessed portion 62d is formed in the flange portion 62b and the like. However, instead of forming the recess 62d in the flange portion 62b or the like, a recess 64e in which the adhesive 66 is accommodated may be formed in a region of the cutting blade 64 corresponding to the annular surface 62c.

FIG. 7(A) is a front view of a cutting blade 64 according to a third modification. The recesses 64e of the cutting blade 64 are a plurality of slits each having a rectangular shape and provided radially from the inner circumference to the outer circumference of the cutting blade 64. Each slit penetrates from one surface 64a of the cutting blade 64 to the other surface 64b.

Furthermore, when the cutting blade 64 is attached to the annular base 62, each slit is formed from the inner circumferential end 62f (indicated by a broken line) of the annular surface 62c to the outer circumferential edge 62g (indicated by a broken line) of the annular surface 62c. is formed in an area corresponding to a predetermined range that is not reached.

Here, an experiment conducted to confirm the relationship between the number of slits and the amplitude of the cutting blade 64 in the radial direction will be described. In this experiment, a flange portion 62b having no recess 62d on the annular surface 62c and a presser base 68 having no recess 68b on the annular surface 68a had a plurality of slits (recesses 64e) shown in FIG. 7(A). A cutting blade 60 formed by sandwiching a cutting edge 64 was used.

Diamond abrasive grains with a grain size of #1000 were used as the abrasive grains 64c of the cutting blade 64, and metal bonds were used as the bond 64d. The outer diameter of the cutting blade 64 was 58 mm, the inner diameter was 40 mm, and the thickness of the cutting blade 64 was 0.1 mm.

The shape of each slit in the cutting blade 64 is a rectangular shape having a longitudinal part in the radial direction of the cutting blade 64, the longitudinal part of the strip is 5 mm, and the width of the strip is 2 mm. An epoxy adhesive was used as the adhesive 66 for fixing the presser foot base 68.

[Experimental Example 1] In Experimental Example 1, a cutting blade 60 is formed by a cutting blade 64 having 32 slits, and an AC voltage having a frequency of 40 kHz and a peak value of 73 V is applied to an ultrasonic vibrator 72 from an AC power source 82. was applied to. At this time, the amplitude of the cutting blade 64 in the radial direction was 4.5 μm. However, the radial amplitude of the cutting edge 64 is preferably 5.0 μm or more.

[Experimental Example 2] Therefore, in order to fix the cutting blade 64 more firmly, the cutting blade 60 was formed by the cutting blade 64 having 64 slits, and an AC voltage having a frequency of 40 kHz and a peak value of 60 V was applied. An electric current was applied to the ultrasonic transducer 72 from an AC power source 82 . At this time, the amplitude of the cutting blade 64 in the radial direction was 5.0 μm.

[Experimental Example 3] In order to fix the cutting blade 64 more firmly, the cutting blade 60 was formed by the cutting blade 64 having 100 slits, and an AC voltage having a frequency of 40 kHz and a peak value of 40 V was applied to the AC power source. 82 to the ultrasonic transducer 72. At this time, the amplitude of the cutting blade 64 in the radial direction was 5.0 μm. The results of Experimental Examples 1 to 3 are shown in Table 1.

As shown in Experimental Examples 2 and 3, if a cutting blade 64 having 64 or more slits is used, the radial amplitude of the cutting blade 64 can be reduced to 5.0 μm even if the peak value of the applied voltage is 60 V or less. did it. If the peak value of the applied voltage is too high, the ultrasonic transducer 72 will be burnt, so in order to achieve a predetermined amplitude, it is an effective method to increase the number of slits and firmly fix the cutting blade 64. I can say that there is.

In addition, the inventor found that the higher the degree of concentration of the abrasive grains 64c, the more difficult it is for the cutting blade 64 to vibrate in the radial direction. Therefore, in order to reduce the peak value of the applied voltage, the degree of concentration of the abrasive grains 64c may be lowered.

By the way, the shape of the recess 64e of the cutting blade 64 is not limited to the example shown in FIG. 7(A). FIG. 7(B) is a front view of a cutting blade 64 according to a fourth modification. The recesses 64e of the cutting blade 64 are a plurality of slits provided discretely along the circumferential direction of the cutting blade 64.

When the cutting blade 64 is attached to the annular base 62, each slit is formed at a predetermined distance from the inner circumferential end 62f (indicated by a broken line) of the annular surface 62c to the outer circumferential edge 62g (indicated by a broken line) of the annular surface 62c. It is formed in an area corresponding to the range of .

Each slit penetrates from one surface 64a of the cutting blade 64 to the other surface 64b. Further, although the recessed portion 64e is formed so as to be divided into eight equal parts in the circumferential direction by a plurality of slits, the recessed part 64e does not necessarily have to be divided into eight equal parts, and may be divided into any number of equal parts.

In the above-described first embodiment and the first to fourth modifications, the case where the recess 62d or the recess 64e is provided in either the annular surface 62c or the cutting blade 64 has been described. However, the annular surface 62c may be provided with a recess 62d, and the cutting blade 64 may also be provided with a recess 64e.

Next, a hub-type cutting blade 90 according to a second embodiment will be described. FIG. 8 is a partially sectional side view of a cutting blade 90 and the like according to the second embodiment. The cutting blade 90 has an annular base (annular base) 92 instead of the annular base 62 and does not have the presser base 68. This point is mainly different from the first embodiment.

The annular base 92 has an annular center portion 92a. A through opening 90a having substantially the same diameter as the outer circumferential surface 50a of the first boss portion 50 is formed near the central axis of the central portion 92a. An annular flange portion 92b is provided on the outer peripheral side of the through opening 90a so as to surround the central portion 92a.

The flange portion 92b has inner and outer annular surfaces 92c that support the annular cutting blade 64, respectively. In the annular surface 92c of the flange portion 92b according to the second embodiment, an annular recess 92d is continuously provided along the circumferential direction of the flange portion 92b, as in FIG. 6(A).

The recess 92d is a space for accommodating the adhesive 66. When the adhesive 66 is annularly applied to one surface 64a of the cutting blade 64, when the one surface 64a comes into contact with the annular surface 92c, the cutting blade 64 is coated with the layer of adhesive 66 formed on each of the annular surface 92c and the recess 92d. is fixed to the annular surface 92c.

Note that, as shown in FIG. 6(B), the recesses 92d may be provided discretely in the circumferential direction of the annular surface 92c. Alternatively, the cutting blade 64 shown in FIGS. 7(A) and 7(B) may be fixed with an annular base 92 having a flange portion 92b having no recess 92d on an annular surface 92c. In addition, the structure, method, etc. according to the above embodiments can be modified and implemented as appropriate without departing from the scope of the objective of the present invention.

2: Cutting device 4: Base, 4a, 4b, 4c: Opening 6: Cassette elevator 8: Cassette 10: X-axis moving mechanism, 10a: Table cover 11: Workpiece 12: Bellows-shaped cover 13: Annular frame 14: Chuck table, 14a: Holding surface 15: Dicing tape 16: Clamp 18: Cutting unit 20: Support structure 21: Workpiece unit 22: Cutting unit moving mechanism 24: Y-axis guide rail, 26: Y-axis moving plate, 28: Y-axis ball screw 30: Z-axis guide rail, 32: Z-axis moving plate, 34: Z-axis ball screw 36: Z-axis pulse motor 38: Spindle housing 40: Housing body, 40a: Spindle, 40b: Opening 42: Housing cover, 42a : through opening, 42b: locking part, 42c: screw hole 44: screw 46: blade mount, 46a: through opening 48: flange part, 48a: annular surface 50: first boss part, 50a: outer peripheral surface 52: first 2 boss portion 56: washer, 58: bolt 60: cutting blade, 60a: through opening 62: annular base, 62a: center portion, 62b: flange portion, 62c: annular surface, 62d: recessed portion 62e: support surface, 62f : Inner peripheral end, 62g: Outer peripheral end 64: Cutting blade, 64a: One side, 64b: Other side,
64c: Abrasive grain, 64d: Bond, 64e: Recess 66: Adhesive 68: Presser base, 68a: Annular surface, 68b: Recess 70: Mount nut, 70a: Through opening 72: Ultrasonic vibrator 74a: First power supply Terminal, 74b: Second power supply terminal 76a: First wiring, 76b: Second wiring 78: First coil, 80: Second coil 82: AC power supply 84: Imaging unit 86: Cleaning unit 90: Cutting blade, 90a : Through opening 92: Annular base, 92a: Center portion, 92b: Flange portion, 92c: Annular surface, 92d: Recessed portion

Claims (3)

A hub-type cutting blade,
The cutting blade used in a cutting device that cuts a workpiece held on a chuck table while applying ultrasonic vibration to the cutting blade attached to a spindle via a blade mount,
an annular cutting blade having abrasive grains fixed with a bond;
An annular surface having a through opening that fits into the central boss portion of the blade mount, and an annular surface provided on the outer peripheral side of the through opening and fixed to a part of one annular surface of the cutting blade with an adhesive. comprising a base;
The annular surface of the annular base is not provided with a recess;
A region of the cutting blade corresponding to the annular surface is provided with a recess in which the adhesive is accommodated, and a layer of the adhesive is formed in the recess of the cutting blade. Features a hub-shaped cutting blade. The recess is
A plurality of slits provided in the cutting blade radially from the inner circumference to the outer circumference of the cutting blade, or
The hub-type cutting blade according to claim 1, characterized in that the slits are a plurality of slits provided in the cutting blade discretely along the circumferential direction of the cutting blade. It further includes an annular presser foot base,
3. The annular surface of the presser foot base in contact with the cutting blade does not have a recess, and the presser foot base and the annular base sandwich the cutting blade. Hub-shaped cutting blade.

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