JP2007021701A - Cutting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting device that allows a user to continuously use an ultrasonic transducer without replacing it even if a cutting blade is replaced when it reaches the end of its service lifetime, and also, is capable of easily applying an AC voltage to the ultrasonic transducer. <P>SOLUTION: The cutting device includes a cutting means provided with a chuck table for holding a workpiece and a cutting blade for cutting the workpiece held by the chuck table. The cutting means is provided with a rotary spindle and first/second flange members arranged to the end part of the rotary spindle and clamping the cutting blade. The cutting device is provided with the ultrasonic transducer arranged to at least either of the first/second flange members and a voltage application means for applying the AC voltage to the ultrasonic transducer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cutting apparatus for cutting a workpiece such as a semiconductor wafer or an optical device wafer.

  In the semiconductor device manufacturing process, a plurality of regions are partitioned by dividing lines called streets arranged in a lattice pattern on the surface of a substantially wafer-shaped semiconductor wafer, and devices such as ICs, LSIs, etc. are partitioned in the partitioned regions. Form. Then, the semiconductor wafer is cut along the streets to divide the region in which the device is formed to manufacture individual semiconductor chips. In addition, optical device wafers with gallium nitride compound semiconductors laminated on the surface of sapphire substrates are divided into individual light emitting diodes, laser diodes, CCDs and other optical devices by cutting along the streets. It's being used.

  The above-described cutting along the wafer street is usually performed by a cutting device called a dicer. This cutting apparatus includes a chuck table for holding a workpiece such as a wafer, a cutting means for cutting the workpiece held on the chuck table, and a cutting for relatively moving the chuck table and the cutting means. And feeding means. The cutting means includes a spindle unit that includes a rotary spindle, a cutting blade mounted on the rotary spindle, and a drive mechanism that rotationally drives the rotary spindle. In such a cutting apparatus, the workpiece held on the cutting blade and the chuck table is relatively cut and fed while rotating the cutting blade at a rotational speed of 20000 to 40000 rpm.

  However, brittle hard materials such as silicon, sapphire, silicon nitride, glass and lithium tantalate are used for the wafer on which the device is formed. There is a problem of lowering. Also, a wafer with high Mohs hardness such as sapphire is very difficult if not impossible to cut with a cutting blade.

In order to solve the above-described problems, an ultrasonic vibrator is fixed to the surface of the cutting blade, and an AC voltage is applied to the ultrasonic vibrator so that cutting is performed while applying ultrasonic vibration to the cutting blade. A cutting device has been proposed. (For example, refer to Patent Document 1.)
Japanese Patent Laid-Open No. 2004-291636

  Thus, since the cutting apparatus disclosed in Japanese Patent Application Laid-Open No. 2004-291636 has a configuration in which an ultrasonic vibrator is fixed to a cutting blade, the ultrasonic vibrator must be discarded along with the life of the cutting blade. It is uneconomical. Further, since the ultrasonic vibrator is fixed to the cutting blade, it is very difficult to configure a circuit for applying an AC voltage to the ultrasonic vibrator.

  The present invention has been made in view of the above facts, and the main technical problem thereof is that the ultrasonic vibrator can be used without replacement even when the cutting blade reaches the end of its life and is replaced. An object of the present invention is to provide a cutting device that can easily apply an alternating voltage to a child.

In order to solve the main technical problem, the present invention includes a chuck table for holding a workpiece, and a cutting means including a cutting blade for cutting the workpiece held on the chuck table,
In the cutting apparatus, wherein the cutting means includes a rotary spindle, and a first flange member and a second flange member that are disposed at an end of the rotary spindle and sandwich the cutting blade.
An ultrasonic transducer disposed on at least one of the first flange member and the second flange member;
Voltage applying means for applying an alternating voltage to the ultrasonic vibrator,
A cutting device is provided.

  The ultrasonic vibrator includes an annular piezoelectric body polarized in the axial direction of the rotary spindle and electrode plates disposed on both side polarization surfaces of the piezoelectric body, and the voltage applying means includes ultrasonic vibration. An alternating voltage is applied to the child electrode plate. The voltage application means includes a lead wire disposed in an axially formed hole in the center of the rotary spindle and connected to an AC power source, a rotary spindle and the first flange member disposed on the lead wire. The electrode terminal is connected to the electrode plate of the ultrasonic transducer while being connected. It is desirable that the ultrasonic transducer is disposed on each of the first flange member and the second flange member.

  According to the present invention, since the ultrasonic vibrator is disposed on at least one of the first flange member and the second flange member, when the cutting blade is replaced according to its life, only the cutting blade is replaced. Can do. Therefore, it is economical because it is not necessary to discard the ultrasonic vibrator together with the cutting blade that has reached the end of its life. Further, according to the present invention, since the ultrasonic vibrator is disposed on at least one of the first flange member and the second flange member, an AC voltage can be easily applied to the ultrasonic vibrator. .

  Hereinafter, a preferred embodiment of a cutting device configured according to the present invention will be described in more detail with reference to the accompanying drawings.

  FIG. 1 shows a perspective view of a cutting device constructed in accordance with the present invention. The cutting device in the illustrated embodiment includes a device housing 2 having a substantially rectangular parallelepiped shape. In the apparatus housing 2, a chuck table 3 for holding a workpiece is disposed so as to be movable in a direction indicated by an arrow X that is a cutting feed direction. The chuck table 3 includes a suction chuck support 31 and a suction chuck 32 disposed on the suction chuck support 31. A workpiece is illustrated on a holding surface which is the upper surface of the suction chuck 32. Suction holding is performed by operating a suction means that does not. The chuck table 3 is configured to be rotatable by a rotation mechanism (not shown). The chuck table 31 is provided with a clamp 33 for fixing a support frame that supports a wafer, which will be described later, via a protective tape as a workpiece. The chuck table 3 configured as described above can be moved in a cutting feed direction indicated by an arrow X by a cutting feed means (not shown).

The cutting apparatus in the illustrated embodiment includes a spindle unit 4 as cutting means. The spindle unit 4 is mounted on a moving base (not shown) and is adjusted to move in a direction indicated by an arrow Y that is an indexing direction and a direction indicated by an arrow Z that is a cutting direction. The rotary spindle 42 is supported, and a cutting blade 43 attached to the tip of the rotary spindle 42 is provided.
The cutting blade 43 and its mounting structure will be described with reference to FIGS. The cutting blade 43 is composed of a grindstone blade formed by bonding abrasive grains made of diamond or the like with a binder to form an annular shape. As this cutting blade, a resinoid blade in which abrasive grains are kneaded into a resin bond material and molded into a ring and fired, a metal blade in which abrasive grains are kneaded into a metal bond material and molded into a ring, and fired, aluminum, etc. An electroformed blade in which abrasive grains are bonded to the side surface of the base formed by metal plating such as nickel is used. In addition, the diameter of the fitting hole 431 of the cutting blade 43 formed in an annular shape is formed so as to fit into a mounting portion 52 of the first flange member 5 described later.

  As shown in FIG. 3, the cutting blade 43 configured as described above includes a first flange member 5 mounted on a rotary spindle 42 rotatably supported on a spindle housing 41 of the cutting apparatus, and the first flange member 5. It is clamped and fixed by a second flange member 6 disposed opposite to the flange member 5. As shown in FIGS. 2 and 3, the first flange member 5 includes an annular flange portion 51 and a cylindrical mounting portion 52 formed to protrude from the center of the flange portion 51 to the side. ing. An annular recess 511 is formed on the side surface of the flange portion 51 on the mounting portion 52 side. The mounting portion 52 is formed with a fitting hole 521 penetrating in the axial direction, and a male screw 522 is formed on the outer peripheral surface at the tip portion. The inner peripheral surface of the fitting hole 521 is formed in a tapered surface corresponding to the tapered surface 421 formed at the tip of the rotary spindle 42. The second flange member 6 is formed in an annular shape having a fitting hole 61, and an annular recess 62 is formed on a side surface facing the flange portion 51 of the first flange member 5. The fitting hole 61 has a diameter that fits into the mounting portion 52 of the first flange member 5.

  In order to fix the cutting blade 43 by the first flange member 5 and the second flange member 6 described above, the fitting hole 521 formed in the mounting portion 52 of the first flange member 5 as shown in FIG. Is fitted to a tapered surface 421 formed at the tip of the rotary spindle 42. Then, the first flange member 5 is attached to the rotary spindle 42 by screwing the first tightening nut 71 into the male screw 422 formed at the tip of the rotary spindle 42. Next, the fitting hole 431 of the cutting blade 43 is fitted into the mounting portion 52 of the first flange member 5. Then, the fitting hole 61 of the second flange member 6 is fitted into the mounting portion 52 of the first flange member 5. In this way, when the first flange member 5, the cutting blade 43, and the second flange member 6 are fitted to the mounting portion 52 of the first flange member 5, the mounting portion 52 of the first flange member 5 is fitted. The cutting blade 43 is sandwiched and fixed between the first flange member 5 and the second flange member 6 by screwing the second tightening nut 72 into the male screw 522 formed in the above.

  As shown in FIG. 3, the spindle unit 4 as the cutting means in the illustrated embodiment includes a first ultrasonic transducer disposed in an annular recess 511 formed in the flange portion 51 of the first flange member 5. 8a and a second ultrasonic transducer 8b disposed in an annular recess 52 formed in the second flange member 6. The first ultrasonic transducer 8a includes an annular piezoelectric body 81a polarized in the axial direction of the rotary spindle 42, and two annular electrode plates 82a mounted on both side polarization surfaces of the piezoelectric body 81a. 83a and an insulator 84a covering the piezoelectric body 81a and the electrode plates 82a and 83a. The piezoelectric body 81a is formed of piezoelectric ceramics such as barium titanate, lead zirconate titanate, and lithium tantalate. As shown in FIGS. 3 and 4, one electrode plate 82a includes an electrode terminal 821a protruding partly from an opening 841a formed in the insulator 84a. The other electrode plate 83a also includes an electrode terminal 831a provided with a phase of 180 degrees with the electrode terminal 821a provided on the one electrode plate 82a. The electrode terminal 831a protrudes from the opening 84a formed in the insulator 84a and is bent to the surface of the insulator 84a (the surface on the side from which the electrode terminal 821a protrudes). The first ultrasonic transducer 8 a configured in this way is attached to the bottom surface of the annular recess 511 formed in the flange portion 51 of the first flange member 5 with an appropriate adhesive.

  The second ultrasonic transducer 8b includes an annular piezoelectric body 81b polarized in the axial direction of the rotary spindle 42, and two annular electrode plates 82b attached to both polarization surfaces of the piezoelectric body 81b. 83b and an insulator 84b covering the piezoelectric body 81b and the electrode plates 82b and 83b. The piezoelectric body 81b is formed of piezoelectric ceramics such as barium titanate, lead zirconate titanate, and lithium tantalate, as with the piezoelectric body 81a. One electrode plate 82b includes an electrode terminal 821b that is partially bent along the inner peripheral surface of the insulator 84b as shown in FIGS. The other electrode plate 83b also includes an electrode terminal 831b which is provided with a phase of 180 degrees with the electrode terminal 821b provided on the one electrode plate 82b and is bent along the inner peripheral surface of the insulator 84b. ing. The second ultrasonic transducer 8b configured as described above is attached to the bottom surface of the annular recess 62 formed in the second flange member 6 with an appropriate adhesive.

  Continuing the description with reference to FIG. 3, the spindle unit 4 as the cutting means in the illustrated embodiment is a voltage for applying an AC voltage to the first ultrasonic transducer 8a and the second ultrasonic transducer 8b. Application means 9 is provided. The voltage application means 9 includes an AC power source 11, a frequency converter 12 that converts the frequency of the AC power source, lead wires 131 and 132 connected to the AC power source 11, and a taper formed at the tip of the rotary spindle 42. The electrode terminals 141 and 142 exposed on the surface 421 and the electrode terminals 151 exposed on the inner peripheral surface of the fitting hole 521 formed in the mounting portion 52 of the first flange member 5. , 152, electrode terminals 161 and 162 disposed on the flange portion 51 of the first flange member 5, and electrode terminals disposed on the outer peripheral surface of the mounting portion 52 of the first flange member 5. 171 and 172 are provided.

  The lead wires 131 and 132 are covered with an insulating member and disposed in a hole 423 formed in the axial direction at the center of the rotary spindle 42. One end of each of the lead wires 131 and 132 is connected to the AC power source 11 via the brushes 181 and 182 and the electric wiring 191 and 192. The electrode terminals 141 and 142 disposed so as to be exposed on the tapered surface 421 formed at the tip of the rotary spindle 42 are disposed with a phase of 180 degrees with respect to each other, and one electrode terminal 141 is disposed on one lead wire 131. The other electrode terminal 142 is connected to the other one lead wire 132. The electrode terminals 151 and 152 disposed on the inner peripheral surface of the fitting hole 521 formed in the mounting portion 52 of the first flange member 5 are disposed with a phase of 180 degrees from each other. The electrode terminal 151 is in contact with one electrode terminal 141 provided on the rotary spindle 42, and the other electrode terminal 152 is in contact with the other electrode terminal 142 provided on the rotary spindle 42.

  The electrode terminals 161 and 162 disposed on the flange portion 51 of the first flange member 5 are disposed with a phase of 180 degrees, and one electrode terminal 161 constitutes the first ultrasonic transducer 8a. One electrode plate 82a is in contact with the electrode terminal 821a, and the other electrode terminal 162 is in contact with the electrode terminal 831a of the other electrode plate 83a constituting the first ultrasonic transducer 8a. The electrode terminals 161 and 162 configured in this way are connected to the electrode terminals 151 and 152 by conducting wires 201 and 202, respectively. The electrode terminals 171 and 172 disposed on the outer peripheral surface of the mounting portion 52 of the first flange member 5 are disposed with a phase of 180 degrees, and one electrode terminal 171 is disposed in the second ultrasonic wave. The electrode terminal 821b of one electrode plate 82b constituting the vibrator 8b is in contact with the electrode terminal 821b of the other electrode plate 83b constituting the second ultrasonic vibrator 8b. The electrode terminals 171 and 172 configured in this way are connected to the electrode terminals 151 and 152 by conducting wires 203 and 204, respectively. The electrode terminals 141 and 142 are disposed on the rotary spindle 42 via an insulating member (not shown), and the electrode terminals 151, 152, 161, 162, 171, and 172 are provided via an insulating member (not shown). The flange portion 51 of the first flange member 5 is disposed. As described above, in the illustrated embodiment, since the first ultrasonic transducer 8a and the second ultrasonic transducer 8b are disposed on the first flange member 5 and the second flange member 6, the rotary spindle 42 and between the one electrode plate 82a and the other electrode plate 83a of the first ultrasonic transducer 8a and the second ultrasonic vibration via the electrode terminals disposed on the first flange member 5 and the first flange member 5. An AC voltage can be easily applied between one electrode plate 82b and the other electrode plate 83b of the child 8b.

  When the voltage applying means 9 configured as described above is energized, an alternating voltage is applied between one electrode plate 82a and the other electrode plate 83a of the first ultrasonic transducer 8a, and the second An AC voltage is applied between one electrode plate 82b and the other electrode plate 83b of the ultrasonic transducer 8b. As a result, the first ultrasonic transducer 8a and the second ultrasonic transducer 8b repeatedly displace in the radial direction and vibrate ultrasonically. Therefore, the first flange member 5 and the second flange member 6 on which the first ultrasonic transducer 8a and the second ultrasonic transducer 8b are mounted also ultrasonically vibrate in the radial direction, and the first flange member 5 The cutting blade 43 sandwiched between the second flange members 6 ultrasonically vibrates in the radial direction. The radial displacement amounts of the first flange member 5, the second flange member 6, and the cutting blade 43 are determined by the AC voltage applied to the first ultrasonic transducer 8a and the second ultrasonic transducer 8b. The higher the higher. The inventors of the present invention form the piezoelectric body 81a and the piezoelectric body 81b constituting the first ultrasonic vibrator 8a and the second ultrasonic vibrator 8b with lead zirconate titanate and apply them by the voltage applying means 9. The amount of displacement was measured on the cutting blade 43 with an AC voltage frequency of 20 kHz and an input voltage of 100 V. As a result, when the cutting blade 43 was a resinoid blade, it was displaced in the 2 to 3 μm diameter direction, and when the cutting blade 43 was an electroformed blade, it was displaced in the 6 to 8 μm diameter direction. The reason why the displacement amount of the resinoid blade is smaller than the displacement amount of the electroformed blade is considered to be because the resinoid blade has higher vibration absorption than the electroformed blade.

  The spindle unit 4 as the cutting means configured as described above is moved in the index feed direction indicated by the arrow Y in FIG. 1 by the index feed means (not shown), and at the arrow Z in FIG. 1 by the notch feed means (not shown). It can be moved in the infeed direction shown.

  Referring back to FIG. 1, the description of the cutting apparatus in the illustrated embodiment is for imaging the surface of the workpiece held on the chuck table 3 and detecting a region to be cut by the cutting blade 43. The alignment means 22 is provided. The alignment unit 22 includes an image pickup unit including an optical unit such as a microscope or a CCD camera. In addition, the cutting apparatus includes a display unit 23 that displays an image captured by the alignment unit 22.

  In the cassette mounting area 24a of the apparatus housing 2, a cassette mounting table 24 for mounting a cassette for storing a workpiece is disposed. This cassette mounting table 24 is configured to be movable in the vertical direction by lifting means (not shown). On the cassette mounting table 24, a cassette 25 for storing the workpiece W is mounted. The workpiece W accommodated in the cassette 25 has a grid-like street formed on the surface of the wafer, and devices such as capacitors, LEDs, and circuits are formed in a plurality of rectangular areas partitioned by the grid-like street. Has been. The workpiece W formed in this way is accommodated in the cassette 25 with the back surface adhered to the surface of the protective tape T mounted on the annular support frame F.

  In the illustrated embodiment, the cutting device is supported by a workpiece W (annular frame F supported by a protective tape T) accommodated in a cassette 25 placed on a cassette placement table 24. ) To the temporary table 26, a conveying means 28 for conveying the workpiece W conveyed to the temporary table 26 onto the chuck table 3, and a workpiece cut on the chuck table 3. A cleaning unit 29 that cleans the workpiece W and a cleaning / conveying unit 30 that transports the workpiece W cut on the chuck table 3 to the cleaning unit 29 are provided.

The operation of the cutting apparatus configured as described above will be briefly described.
The workpiece W accommodated in a predetermined position of the cassette 25 placed on the cassette placement table 24 is positioned at the carry-out position when the cassette placement table 24 moves up and down by a lifting means (not shown). Next, the unloading means 27 is moved forward and backward to unload the workpiece W positioned at the unloading position onto the temporary placement table 26. The workpiece W carried out to the temporary placement table 26 is conveyed onto the chuck table 3 by the turning operation of the conveying means 28. When the workpiece W is placed on the chuck table 3, suction means (not shown) is operated to suck and hold the workpiece W on the chuck table 3. Further, the support frame F that supports the workpiece W via the protective tape T is fixed by the clamp 33. The chuck table 3 holding the workpiece W in this way is moved to a position immediately below the alignment means 22. When the chuck table 3 is positioned immediately below the alignment means 22, the street formed on the workpiece W is detected by the alignment means 22, and the spindle unit 4 is moved and adjusted in the arrow Y direction which is the indexing direction. A precision alignment operation with the cutting blade 43 is performed.

  Thereafter, the cutting blade 43 is cut and fed by a predetermined amount in the direction indicated by the arrow Z and rotated in the predetermined direction, while the chuck table 3 holding the workpiece W is sucked and held in the direction indicated by the arrow X (cutting blade). The semiconductor wafer W held on the chuck table 3 is cut along a predetermined street by the cutting blade 43 by moving at a predetermined cutting feed rate in a direction orthogonal to the rotation axis 43. In this cutting process, the voltage applying means 9 is energized, and the first ultrasonic transducer 8a and the second ultrasonic transducer 8b are ultrasonically vibrated in the radial direction as described above. As a result, since the cutting blade 43 is ultrasonically vibrated in the radial direction via the first flange member 5 and the second flange member 6, the cutting resistance by the cutting blade 43 is reduced, so that the wafer W is difficult to sapphire or the like. Even a cutting material can be easily cut.

  As described above, when the workpiece W is cut along a predetermined street, the chuck table 3 is indexed and fed in the direction indicated by the arrow Y by the street interval, and the cutting operation is performed. When the cutting operation is performed along all the streets extending in the predetermined direction of the workpiece W, the chuck table 3 is rotated 90 degrees to extend in a direction perpendicular to the predetermined direction of the workpiece W. By performing a cutting operation along existing streets, all the streets formed in a lattice shape on the workpiece W are cut and divided into individual chips. The divided chips do not fall apart due to the action of the protective tape T, and the state of the wafer supported by the frame F is maintained.

  As described above, when the cutting operation is completed along the street of the workpiece W, the chuck table 3 holding the workpiece W is returned to the position where the workpiece W is first sucked and held. Then, the suction holding of the workpiece W is released. Next, the workpiece W is transferred to the cleaning unit 29 by the cleaning transfer unit 30. The workpiece W conveyed to the cleaning means 30 is cleaned and dried here. The workpiece W thus cleaned and dried is carried out to the temporary table 24 by the conveying means 28. Then, the workpiece W is stored in a predetermined position of the cassette 25 by the unloading means 27. Accordingly, the carry-out means 27 also has a function as a carry-in means for carrying the processed workpiece W into the cassette 25.

By continuing the above-described cutting operation, the cutting blade 43 is worn. When this wear reaches a predetermined amount, the cutting blade 43 is replaced. In the illustrated embodiment, the first ultrasonic transducer 8a and the second ultrasonic transducer 8b are the first flange member 5 and the second ultrasonic transducer 8b. Since the flange member 6 is disposed, only the cutting blade 43 can be replaced. Therefore, it is not necessary to discard the first ultrasonic transducer 8a and the second ultrasonic transducer 8b together with the cutting blade 43 that has reached the end of its life, which is economical.
In the above-described embodiment, an example is shown in which the ultrasonic transducers are disposed on the first flange member 5 and the second flange member 6, respectively. It may be arranged on either one of the second flange members 6.

The perspective view of the cutting device comprised according to this invention. The disassembled perspective view of the spindle unit with which the cutting apparatus shown in FIG. 1 is equipped. FIG. 2 is a cross-sectional view of a main part of a spindle unit equipped in the cutting apparatus shown in FIG. FIG. 4 is a front view of a first ultrasonic transducer mounted on the spindle unit shown in FIG. 3. FIG. 4 is a front view of a second ultrasonic transducer attached to the spindle unit shown in FIG. 3.

Explanation of symbols

2: device housing 3: chuck table 4: spindle unit 41: spindle housing 42: rotating spindle 43: cutting blade 5: first flange member 51: flange portion 52: mounting portion 6: second flange member 8a: first Ultrasonic transducer 81a: piezoelectric member 82a, 83a: electrode plate 84a: insulator 8b: first ultrasonic transducer 81b: piezoelectric member 82b, 83b: electrode plate 84b: insulator 9: voltage applying means 11: AC Power supply 12: Frequency converter 22: Alignment means 23: Display means 24: Cassette placement table 25: Cassette 26: Temporary placement table 27: Unloading means 28: Conveying means 29: Cleaning means 30: Cleaning and conveying means

Claims (4)

A chuck table for holding a workpiece, and a cutting means including a cutting blade for cutting the workpiece held on the chuck table;
In the cutting apparatus, wherein the cutting means includes a rotary spindle, and a first flange member and a second flange member that are disposed at an end of the rotary spindle and sandwich the cutting blade.
An ultrasonic transducer disposed on at least one of the first flange member and the second flange member;
Voltage applying means for applying an alternating voltage to the ultrasonic vibrator,
The cutting device characterized by the above.   The ultrasonic transducer includes an annular piezoelectric body polarized in the axial direction of the rotary spindle and electrode plates respectively disposed on both polarization surfaces of the piezoelectric body, and the voltage applying means includes the ultrasonic wave The cutting apparatus according to claim 1, wherein an alternating voltage is applied to the electrode plate of the vibrator.   The voltage applying means is disposed in a hole formed in the axial direction in the center of the rotating spindle and connected to an AC power source, and is disposed on the rotating spindle and the first flange member. 3. The cutting apparatus according to claim 2, further comprising an electrode terminal connected to the electrode plate and connected to the electrode plate of the ultrasonic transducer.   The cutting apparatus according to any one of claims 1 to 3, wherein the ultrasonic transducer is disposed on each of the first flange member and the second flange member.

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