Deburring device and deburring method

Abstract

To remove burrs generated in a workpiece.SOLUTION: A deburring device 22 comprises: an ultrasonic oscillation unit 50; and a water layer formation part 31 that forms a water layer 34 between an upper surface of a workpiece 1 and a lower surface of the ultrasonic oscillation unit 50. The ultrasonic oscillation unit 50 comprises two column-like ultrasonic horns arranged with an interval. The deburring device 22 comprises: a control part 59 that relatively moves the ultrasonic oscillation unit 50 and a table 27 with a horizontal movement mechanism; and a power control part 583 that continuously changes a phase of a high-frequency power to the other ultrasonic horn with respect to the phase of the high frequency power to one ultrasonic horn. By continuously changing the phase of the high frequency power of the one ultrasonic horn of the two ultrasonic horns, a place where an ultrasonic vibration vibrated from the two ultrasonic horns is increased is moved on the upper surface of the workpiece 1 to remove burrs.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to deburring. [Background technology]

[0002] When a workpiece is processed with a cutting blade or laser, burrs may be formed in the kerf (cutting marks). For example, if the workpiece is a semiconductor workpiece, these burrs can cause poor connection when the chips obtained by dividing the workpiece are mounted on a substrate or the like. For this reason, it is desirable to remove the burrs in advance.

[0003] A technology related to such a problem is described, for example, in Patent Document 1. Patent Document 1 describes a technology for removing burrs from a workpiece by spraying water toward the burrs. This technology removes burrs by spraying water from a nozzle toward the workpiece while moving the tip of the nozzle back and forth along an arc-shaped path above a spinner table that rotates while holding the workpiece. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-027183 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology described in Patent Document 1 has room for improvement in terms of shortening the time required to remove burrs from the kerf. Also, there is room for improvement in terms of reliably removing burrs from the kerf. The present invention has been made in consideration of these points, and has an object to provide a deburring device and a deburring method for removing burrs from plate-shaped workpieces such as semiconductor workpieces. [Means for solving the problem]

[0006] A deburring device according to one embodiment of the present invention is a burr removal device for removing burrs formed in a kerf of a workpiece having a kerf formed by a cutting blade or a laser beam, and includes a table for holding an underside of the workpiece, an ultrasonic oscillation unit arranged with a gap on an upper surface of the workpiece held on the table and oscillating ultrasonic vibrations against the upper surface of the workpiece, and a water layer forming section for forming a water layer between the upper surface of the workpiece held on the table and a lower surface of the ultrasonic oscillation unit, the ultrasonic oscillation unit including a plate and two cylindrical ultrasonic horns arranged at a distance from each other, and the burr removal device further includes a water layer forming section for forming a water layer between the upper surface of the workpiece held on the table and a lower surface of the ultrasonic oscillation unit, the ultrasonic oscillation unit including a plate and two cylindrical ultrasonic horns arranged with a gap therebetween, and the burr removal device further includes a water layer forming section for forming a water layer between the upper surface of the workpiece held on the table and a lower surface of the ultrasonic oscillation unit, the water layer forming section being configured to form a water layer between the upper surface of the workpiece held on the table and the lower surface of the ultrasonic oscillation unit, the ultrasonic oscillation unit including a plate and two cylindrical ultrasonic horns arranged with a gap therebetween, and the burr removal device further includes a water layer forming section for forming a water layer between the upper surface of the workpiece held on the table and the lower surface of the ultrasonic oscillation unit, the water layer forming section being configured to form ... The ultrasonic horn unit is provided with a horizontal movement mechanism which moves one of the ultrasonic horns parallel to the top surface of the table relative to the other, a control unit which moves the ultrasonic oscillation unit and the table relatively using the horizontal movement mechanism, a high frequency power supply which supplies high frequency power to the two ultrasonic horns, and a power control unit which continues to change the phase of the high frequency power supplied by the high frequency power supply to one of the ultrasonic horns with respect to the phase of the other ultrasonic horn, and by continuing to change the phase of the high frequency power of one of the two ultrasonic horns, the point on the top surface of the workpiece where the ultrasonic vibrations oscillated from the two ultrasonic horns are amplified is moved, and the burrs are removed. Effect of the Invention

[0007] According to the present invention, burrs formed on a workpiece can be removed. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a perspective view of a frame set including a workpiece according to one embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of a cutting device according to one embodiment. [Diagram 3] 1 is a cross-sectional view of a burr removing device according to a first embodiment. [Figure 4] FIG. 2 is a diagram for explaining an ultrasonic horn included in the ultrasonic oscillation unit according to the first embodiment. [Diagram 5]3 is a diagram showing wavefronts of ultrasonic waves in phase output from a pair of ultrasonic horns according to the first embodiment, and points where ultrasonic vibrations in phase interfere with each other constructively and destructively. FIG. [Figure 6] 3A and 3B are diagrams showing waveforms of ultrasonic vibrations output from a pair of ultrasonic horns according to the first embodiment. [Figure 7] 4A to 4C are diagrams illustrating changes in the positions of points where ultrasonic vibrations constructively interfere with each other and points where ultrasonic vibrations destructively interfere with each other, depending on the phase difference between the ultrasonic vibrations output from a pair of ultrasonic horns according to the first embodiment. [Figure 8] FIG. 4 is another diagram illustrating changes in the positions of the constructive and destructive points of ultrasonic vibrations according to the phase difference between the ultrasonic vibrations output from the pair of ultrasonic horns according to the first embodiment. [Figure 9] FIG. 6 is a cross-sectional view of a portion of a burr removing device according to a second embodiment. [Figure 10] This figure shows the wavefronts of ultrasonic waves in phase output from a pair of ultrasonic horns arranged along the planned division line 13, and the points where ultrasonic vibrations in phase interfere with each other constructively and destructively. [Figure 11] 1 is a cross-sectional view of a laser processing apparatus according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] This article describes a technique for removing burrs that occur on a workpiece that has been machined using a cutting blade or a laser beam. Note that, although the following description uses a semiconductor device manufacturing process as an example, the application of the burr removal device described below is not limited to the semiconductor device manufacturing process.

[0010] Fig. 1 is a perspective view of a frame set 11 including a workpiece 1 according to one embodiment. The frame set 11 shown in Fig. 1 is formed by attaching the workpiece 1 to tape 21 that covers an opening of a ring-shaped frame 23, thereby integrating the workpiece 1, tape 21, and frame 23. In the frame set 11, the workpiece 1 is supported by the frame 23 via the tape 21.

[0011] The workpiece 1 according to this embodiment includes, for example, a disk-shaped workpiece, i.e., a wafer, formed using a semiconductor material such as silicon (Si). However, the material of the workpiece 1 is not particularly limited. It is not limited to silicon, and may be other semiconductor substrates such as gallium arsenide, or inorganic material substrates such as ceramic, glass, and sapphire. The shape of the workpiece 1 is not limited to a disk shape, and may be any shape, such as a plate-shaped substrate other than a circular shape.

[0012] The workpiece 1 has a front surface AA and a back surface AB. The front surface AA is provided with a plurality of small regions partitioned by a plurality of planned division lines 13 (also called streets). A device 15 such as an integrated circuit is formed in each of the plurality of small regions. A tape 21 that covers an opening of a frame 23 is attached to the front surface AA of the workpiece 1.

[0013] A film 17 is provided on a back surface AB opposite to the front surface AA. The film 17 is formed not only in the region of the back surface AB that corresponds to the device 15, but also in the region of the back surface AB that corresponds to the planned division lines 13. The film 17 is a metal film made of a metal such as gold, silver, titanium, or nickel, and is formed by using a sputtering method, a deposition method, a chemical vapor deposition (CVD) method, or the like, although there is no particular limitation thereon.

[0014] Fig. 2 is a cross-sectional view of the cutting device 2 according to one embodiment. Hereinafter, as an example of processing the workpiece 1, an example of cutting an area of ​​the workpiece 1 corresponding to the planned division line 13 from the side of the film 17 formed on the back surface AB will be described with reference to Fig. 2.

[0015] The cutting device 2 shown in Figure 2 includes a chuck table 4 that holds a workpiece 1 included in a frame set 11, a plurality of clamps 10 that hold frames 23 included in the frame set 11, and a cutting unit 12 that cuts the workpiece 1 included in the frame set 11 held by the chuck table 4 and the clamps 10.

[0016] The chuck table 4 includes a frame 6 having a recess formed on its upper surface, and a holding plate 8 embedded in the recess of the frame 6. The frame 6 is formed with a flow path B that connects the recess of the frame 6 to a suction source (not shown). The holding plate 8 is a porous plate. A plurality of clamps 10 are provided around the frame 6.

[0017] The cutting unit 12 is provided above the chuck table 4. The cutting unit 12 includes a spindle 14 having a rotation axis approximately parallel to the holding surface C, which is the surface of the holding plate 8, and a cutting blade 16 attached to the spindle 14. The spindle 14 is connected to a rotation drive source (not shown). The cutting blade 16 is rotated by the power of the rotation drive source connected to the spindle 14.

[0018] Furthermore, the chuck table 4 is supported by a moving mechanism (not shown) that moves in a direction (Y-axis direction) approximately parallel to the holding surface C, and a rotating mechanism (not shown) that rotates about an axis approximately perpendicular to the holding surface C. The cutting unit 12 also includes a moving mechanism that moves in a direction approximately parallel to the holding surface C (X-axis direction perpendicular to the Y-axis direction) and in a direction approximately perpendicular to the holding surface C (Z-axis direction).

[0019] The cutting device 2 configured as described above first holds the frame set 11 with the surface AA of the workpiece 1 facing the chuck table 4 in order to cut the area of ​​the workpiece 1 corresponding to the planned division line 13 from the film 17 side. Here, the multiple clamps 10 hold the frame 23. Furthermore, a suction source (not shown) generates a negative pressure on the holding surface C, which is the surface of the holding plate 8, by suction, and the chuck table 4 holds the workpiece 1 via the tape 21 by the negative pressure.

[0020] Next, the cutting device 2 positions the cutting blade 16 in an area corresponding to the planned division line 13. Here, the rotation mechanism supporting the chuck table 4 rotates the chuck table 4 so that the planned division line 13 and the cutting blade 16 are parallel to each other. Next, the chuck table 4 and the cutting unit 12 are moved by a movement mechanism supporting the chuck table 4 and moving the chuck table 4 in the cutting feed direction of the cutting blade 16 and a movement mechanism supporting the cutting unit 12 and moving the cutting unit 12 in the direction of the rotation axis of the spindle 14 which rotates the cutting blade 16, so that the cutting blade 16 is positioned on the area corresponding to the planned division line 13.

[0021] In the cutting device 2, when the cutting blade 16 is positioned over the area corresponding to the planned division line 13 by the moving mechanism supporting the cutting unit 12, the spindle 14 is rotated by the motor to rotate the cutting blade 16, and the cutting unit 12 is lowered to cut the area corresponding to the planned division line 13 from the film 17 side with the cutting blade 16. As a result, a groove D is formed at the position corresponding to the planned division line 13, dividing the small area in which the device 15 is formed. The groove D is an example of a kerf formed in the work 1. The above operation is repeated for all areas corresponding to the planned division lines 13.

[0022] The tape 21 that closes the opening of the frame 23 may be attached to the back surface AB of the workpiece 1, or the groove D may be formed by cutting the workpiece 1 with a cutting blade 16 from the front surface AA side.

[0023] In such cutting processing using the cutting blade 16, the film 17 and the workpiece 1 are cut, generating burrs at the upper end of the groove D. As described above, the burrs generated by the cutting processing may cause poor connection and may degrade the quality of the device. Therefore, in this embodiment, the burrs generated in the workpiece 1 in which the groove D is formed are removed by using a burr removal device 22 shown in FIG.

[0024] (First embodiment) Fig. 3 is a cross-sectional view of the burr removing device 22 according to this embodiment. The burr removing device 22 shown in Fig. 3 is a device that removes burrs formed in a groove D of a workpiece 1 in which the groove D is formed by a cutting blade 16. The burr removing device 22 includes a table 27 that holds the lower surface of the workpiece 1, an ultrasonic oscillation unit 50 that oscillates ultrasonic vibrations with respect to the upper surface of the workpiece 1, and a water layer forming part 31.

[0025] The ultrasonic oscillation unit 50 is disposed with a gap therebetween with respect to the upper surface of the workpiece 1 held on the table 27. The water layer forming section 31 forms a water layer 34 between the upper surface of the workpiece 1 held on the table 27 and the lower surface of the ultrasonic oscillation unit 50. The distance from the lower surface of the ultrasonic oscillation unit 50 (the lower surface of a plate 501 described later) to the upper surface of the workpiece 1 is, for example, 5 mm, and the water layer 34 is formed in this space, and the gap is filled with the water layer 34.

[0026] The table 27 is provided in a space E within a cylindrical housing portion 24 in which the workpiece 1 is housed, together with a clamp 28 that holds a frame 23 that supports the workpiece 1 via a tape 21 .

[0027] The table 27 is a chuck table equipped with a frame 26 having a recess formed therein and a holding plate 25 embedded in the recess, and holds the underside of the workpiece 1. The table 27 is configured to suck and hold the underside of the workpiece 1 on the surface (holding surface) of the holding plate 25 by the suction action of a suction source (not shown) connected to the recess of the frame 26 via a flow path. The holding plate 25 is a porous plate. The clamps 28 are provided around the frame 26 of the table 27.

[0028] With the surface AA of the workpiece 1 (the surface on which the device 15 is formed) facing the table 27, the workpiece 1 is suction-held by the table 27, and the frame 23 is clamped by the clamp 28. In this way, the burr removing device 22 holds the frame set 11.

[0029] Furthermore, the table 27 is fixed to a spindle 30 that is rotated by a table rotation motor 32. By rotating the table 27 by the rotation of the table rotation motor 32, the orientation of the workpiece 1 held on the table 27 can be changed.

[0030] In the burr removing device 22 configured as above, the ultrasonic oscillation unit 50 applies ultrasonic vibration to the water layer 34 formed by the water layer forming part 31 in the following procedure. As a result, the burr removing device 22 removes burrs formed on the workpiece 1 by using the ultrasonic vibration transmitted through the water layer 34.

[0031] First, when the workpiece 1 is held on the table 27, the control unit 59 controls the rotation of the table rotation motor 32 so that the division lines 13 formed in a lattice pattern on the workpiece 1 are parallel to the X-axis direction and the Y-axis direction. In other words, grooves D (kerfs) are formed along the X-axis direction and the Y-axis direction, and the X-axis direction and the Y-axis direction are the directions in which the grooves D (kerfs) extend.

[0032] Next, the control unit 59 controls the swivel motor 33 to move the water layer forming unit 31 to the upper surface of the workpiece 1 by rotating the swivel motor 33. The water layer forming unit 31 is a nozzle that directs water onto the workpiece 1, and under the control of the control unit 59, the burr removing device 22 sprays water supplied from a water supply source (not shown) from the water layer forming unit 31 onto the workpiece 1. The water sprayed from the nozzle (water layer forming unit 31) onto the workpiece 1 forms a water layer 34 on the workpiece 1 due to its surface tension.

[0033] The burr removal device 22 may form the water layer 34 so that the entire upper surface of the workpiece 1 is covered with the water layer 34, or may form the water layer 34 so that a portion of the upper surface of the workpiece 1, specifically, at least an area including the planned division line 13 to be scanned with ultrasonic vibration, is covered with the water layer 34.

[0034] When the water layer 34 is formed, the control unit 59 controls the swivel motor 33 to rotate the swivel motor 33 to move the water layer forming unit 31 away from above the workpiece 1. Thereafter, the control unit 59 controls the swivel motor 57 to rotate the spindle 56 by the rotation of the swivel motor 57 to move the ultrasonic oscillation unit 50 above the workpiece 1.

[0035] Furthermore, the control unit 59 controls the horizontal movement mechanism 55 to position the ultrasonic oscillation unit 50 at approximately the center of the workpiece 1 by driving the horizontal movement mechanism 55, and then controls the lifting unit 36 ​​to lower the ultrasonic oscillation unit 50 to a position where the lower surface of the ultrasonic oscillation unit 50 contacts the water layer 34 by driving the lifting unit 36. As a result, the space between the upper surface of the workpiece 1 and the lower surface of the ultrasonic oscillation unit 50 is filled with the water layer 34. In other words, the water layer 34 is formed between the upper surface of the workpiece 1 and the lower surface of the ultrasonic oscillation unit 50.

[0036] When the ultrasonic oscillation unit 50 has been positioned relative to the table 27, the control unit 59 controls the power supply unit 58. This causes the ultrasonic oscillation unit 50 to apply ultrasonic vibrations to the water layer 34 formed by the water layer forming unit 31, and as a result, the ultrasonic vibrations are transmitted through the water layer 34 to act on the burrs of the workpiece 1 held on the table 27.

[0037] FIG. 4 is a diagram for explaining an ultrasonic horn included in the ultrasonic oscillation unit 50 according to this embodiment. FIG. 5 is a diagram showing the wavefronts of ultrasonic vibrations in phase output from a pair of ultrasonic horns according to this embodiment, and the constructive and destructive points due to interference of ultrasonic vibrations in phase. The above-mentioned burr removing device 22 is configured to remove burrs generated on the work 1 by amplified ultrasonic vibrations using the interference of ultrasonic vibrations applied to the water layer 34. More specifically, it is configured to remove burrs by moving the location where the ultrasonic vibrations are amplified on the upper surface of the work 1. Hereinafter, with reference to FIG. 3 to FIG. 5, a configuration for removing burrs formed on the work 1 using amplified ultrasonic vibrations, which the burr removing device 22 has, will be described.

[0038] As shown in FIG. 3, the burr removal device 22 includes a horizontal movement mechanism that moves the ultrasonic oscillation unit 50 and the table 27 relatively parallel to the upper surface of the table 27, a power supply unit 58 that controls the ultrasonic oscillation unit 50, and a control unit 59 that controls the movement mechanism and the power supply unit 58.

[0039] The horizontal movement mechanism includes a horizontal movement mechanism 55 which is a Y-axis movement mechanism that moves the ultrasonic oscillation unit 50 and the table 27 relatively in the Y-axis direction, and a horizontal movement mechanism 38 which is an X-axis movement mechanism that moves the ultrasonic oscillation unit 50 and the table 27 relatively in the X-axis direction perpendicular to the Y-axis direction. The horizontal movement mechanism 55 is, for example, a slider that slides an arm supporting the ultrasonic oscillation unit 50 in the Y-axis direction, and is configured to move the ultrasonic oscillation unit 50 in the Y-axis direction relative to the table 27 by moving the ultrasonic oscillation unit 50 in the Y-axis direction. The horizontal movement mechanism 38 is, for example, a table on which the spindle 30 and the table rotation motor 32 are placed, and is configured to move the table 27 in the X-axis direction relative to the ultrasonic oscillation unit 50 by moving the spindle 30 and the table rotation motor 32 in the X-axis direction.

[0040] The above-mentioned spindle 30 and table rotation motor 32 mounted on the horizontal movement mechanism 38 are an example of a rotation mechanism that rotates the table 27 relatively to the ultrasonic oscillation unit 50. In the burr removal device 22, by using the horizontal movement mechanism and the rotation mechanism, it is possible to arbitrarily adjust the position and orientation of the table 27 with respect to the ultrasonic oscillation unit 50, and thus it is possible to adjust the position and orientation of the workpiece 1 with respect to the ultrasonic oscillation unit 50.

[0041] The power supply unit 58 includes a high-frequency power supply 581 and a high-frequency power supply 582 that supply high-frequency power to the two ultrasonic horns of the ultrasonic oscillation unit 50, and a power control unit 583 that controls the power supply to the high-frequency power supply 581 and the high-frequency power supply 582. The control unit 59 is configured, for example, with a processor that executes various processes and a storage unit (memory) that stores various parameters, programs, and the like. The storage unit of the control unit 59 stores a program for executing a burr removal method using the ultrasonic oscillation unit 50 as a part of the control program of the burr removal device 22. Specifically, the control unit 59 executes the program to relatively move the ultrasonic oscillation unit 50 and the table 27 by the horizontal movement mechanism, and to supply power to the ultrasonic oscillation unit 50 by the power supply unit 58. As a result, in the burr removal device 22, burrs are removed by a burr removal method using amplified ultrasonic vibration.

[0042] The ultrasonic oscillation unit 50 includes a plate 501, and two cylindrical ultrasonic horns 51 and 54 arranged at an interval on the plate 501. The diameter of the ultrasonic horns 51 and 54 is, for example, 40 mm, and the distance between the centers of the ultrasonic horns 51 and 54 is, for example, 100 mm. The diameter of the wafer, which is the workpiece 1, is, for example, 200 mm.

[0043] Plate 501 supporting ultrasonic horn 51 and ultrasonic horn 54 is a metal plate made of titanium, stainless steel, aluminum, etc. By providing ultrasonic horn 51 and ultrasonic horn 54 on plate 501, longitudinal waves oscillated from the lower surfaces of ultrasonic horn 51 and ultrasonic horn 54 are converted to transverse waves by plate 501 and resonated. Ultrasonic horn 54 is arranged side by side in a direction parallel to the upper surface of table 27 by being placed on plate 501.

[0044] In this embodiment, the distance between the centers of the ultrasonic horn 51 and the ultrasonic horn 54 is half the diameter of the wafer, and the plate 501 supporting the ultrasonic horn 51 and the ultrasonic horn 54 has a diameter of 140 mm or more. Therefore, by positioning the ultrasonic oscillation unit 50 at the center of the workpiece 1 using a horizontal movement mechanism, most of the workpiece 1 having a diameter of 200 mm is covered by the plate 501. The ultrasonic vibration oscillated through the plate 501 is transmitted to a range wider than the range covered by the plate 501. Therefore, in this embodiment, the ultrasonic vibration can be applied to almost the entire area of ​​the workpiece 1 simply by positioning the ultrasonic oscillation unit 50 at the center of the workpiece 1.

[0045] As shown in Fig. 4, ultrasonic horn 51 includes transducer 52 that generates ultrasonic vibrations, and horn portion 53 that radiates ultrasonic vibrations generated by transducer 52. Transducer 52 is, for example, a bolt-clamped Langevin transducer (BLT) including a piezoelectric element. High-frequency power is supplied to transducer 52 of ultrasonic horn 51 from high-frequency power source 581. Ultrasonic horn 54 is similar to ultrasonic horn 51, except that high-frequency power is supplied to transducer 52 of ultrasonic horn 54 from high-frequency power source 582 (see Fig. 3).

[0046] In the burr removing device 22 configured as described above, the control unit 59 executes a program to remove burrs using amplified ultrasonic vibrations. Below, we will sequentially explain how to apply the amplified ultrasonic vibrations to the burrs and how to perform phase control to efficiently and reliably remove burrs from the workpiece 1 using the amplified ultrasonic vibrations.

[0047] First, the amplified ultrasonic vibration is applied to the burrs by the power supply unit 58 supplying high frequency power to a pair of ultrasonic horns of the ultrasonic oscillation unit 50. In detail, under the control of the power control unit 583, the high frequency power supply 581 supplies high frequency power to the ultrasonic horn 51, and the high frequency power supply 582 supplies high frequency power to the ultrasonic horn 54.

[0048] As a result, the transducer 52 (piezoelectric element) included in each ultrasonic horn is deformed, and ultrasonic vibration is generated from each ultrasonic horn. The ultrasonic vibration transmitted from the transducer 52 to the horn portion 53 is radiated like ripples from the bottom surface of the ultrasonic oscillation unit 50 to the outside of the ultrasonic oscillation unit 50. The ultrasonic vibrations radiated from the above two ultrasonic horns to the outside of the ultrasonic oscillation unit 50 interfere with each other, resulting in positions where the ultrasonic vibrations are constructive (positions where the ultrasonic vibrations are amplified) and positions where they are destructive (positions where the ultrasonic vibrations are attenuated).

[0049] For example, when high frequency power sources 581 and 582 supply high frequency power of the same frequency and phase to ultrasonic horn 51 and ultrasonic horn 54, ultrasonic horn 51 and ultrasonic horn 54 can be regarded as two wave sources that oscillate ultrasonic vibrations of the same frequency and phase. In this case, the positions where the vibrations are constructive and destructive are arranged as shown in FIG. 5.

[0050] In FIG. 5, a circle 81 shown by a solid line among the concentric circles centered on the ultrasonic horn 51 is the wavefront of the ultrasonic vibration emitted from the ultrasonic horn 51, and shows the wavefront at the maximum amplitude in the + direction. A circle 82 shown by a dashed line among the concentric circles centered on the ultrasonic horn 51 is the wavefront of the ultrasonic vibration emitted from the ultrasonic horn 51, and shows the wavefront at the maximum amplitude in the - direction. A circle 91 shown by a solid line among the concentric circles centered on the ultrasonic horn 54 is the wavefront of the ultrasonic vibration emitted from the ultrasonic horn 54, and shows the wavefront at the maximum amplitude in the + direction. A circle 92 shown by a dashed line among the concentric circles centered on the ultrasonic horn 54 is the wavefront of the ultrasonic vibration emitted from the ultrasonic horn 54, and shows the wavefront at the maximum amplitude in the - direction.

[0051] Line SL is a line connecting the positions where ultrasonic vibrations constructively interfere with each other, and line WL is a line connecting the positions where ultrasonic vibrations destructively interfere with each other. Black circle S on line SL is a point where circle 81 and circle 91 or circle 82 and circle 92 overlap, and is a position where ultrasonic vibrations interfere with each other at maximum amplitude and constructively interfere with each other. White circle W on line SL is a point where circle 81 and circle 92 or circle 82 and circle 91 overlap, and is a position where ultrasonic vibrations interfere with each other at maximum amplitude and destructively interfere with each other.

[0052] The constructive position is a position where the difference in distance from ultrasonic horn 51 and ultrasonic horn 54 is equal to an integer multiple of the wavelength of the ultrasonic vibration (i.e., the phase difference is an integer multiple of 2π). Therefore, as shown in Fig. 5, assuming that the ultrasonic waves are spherical waves, the positions where the ultrasonic vibration is amplified are distributed on the midline (perpendicular bisector) between ultrasonic horn 51 and ultrasonic horn 54 and on a hyperbola centered on the midline. The midline is a position where the phase difference is 0 (=2π×0).

[0053] In this way, in the burr removal device 22, the position where the ultrasonic vibrations reinforce each other due to interference occurs around the midline between the ultrasonic horns 51 and 54, and ultrasonic vibrations stronger than those generated from a single ultrasonic horn can be applied to the burrs formed at the reinforced position. This makes it possible to remove burrs efficiently in a short time.

[0054] Next, phase control for reliably removing burrs from workpiece 1 by amplified ultrasonic vibration is realized by power control unit 583 controlling the phase of high frequency power supplied from high frequency power sources 581 and 582. More specifically, when high frequency power sources 581 and 582 supply high frequency power, power control unit 583 continues to change the phase of high frequency power supplied to ultrasonic horn 54 by high frequency power source 582 relative to the phase of high frequency power supplied to ultrasonic horn 51 by high frequency power source 581.

[0055] 5, the distance between the lines SL connecting the constructive positions is approximately half the wavelength (λ / 2) of the ultrasonic vibration between the ultrasonic horns 51 and 54, and the distance becomes longer the further away from the ultrasonic horns 51 and 54. To reliably remove burrs generated on the workpiece 1, it is desirable to apply the amplified ultrasonic vibrations not only to the lines SL in FIG. 5 but also to the entire workpiece 1 including the region between the lines SL, and the burr removal device 22 achieves this by controlling the phase of the high-frequency power.

[0056] 5 shows an example in which there is no phase difference between the ultrasonic vibrations emitted from the ultrasonic horn 51 and the ultrasonic horn 54, but if a phase difference occurs between the ultrasonic vibrations emitted from the ultrasonic horn 51 and the ultrasonic horn 54, the position on the workpiece 1 where the phase difference between the ultrasonic vibrations becomes an integer multiple of 2π also changes, and as a result, the position where the ultrasonic vibrations reinforce each other also changes. Therefore, by continuously or stepwise changing the phase difference between the ultrasonic vibrations emitted from the ultrasonic horn 51 and the ultrasonic horn 54, the position where the ultrasonic vibrations reinforce each other (the position where they destructively reinforce each other) can also be moved little by little.

[0057] Fig. 6 is a diagram showing the waveform of ultrasonic vibration output from a pair of ultrasonic horns according to this embodiment. Fig. 7 and Fig. 8 are diagrams explaining the change in the positions of the constructive and destructive points of ultrasonic vibration according to the phase difference between the ultrasonic vibrations output from a pair of ultrasonic horns according to this embodiment. Hereinafter, with reference to Figs. 5 to 8, a specific description will be given of how the positions where ultrasonic vibrations constructively move by changing the phase of the ultrasonic vibrations oscillated from the ultrasonic horn 54.

[0058] FIG. 6 shows waveform 101 of ultrasonic vibration generated from high frequency power supply 581, and waveforms 102, 103, 104, and 105 of ultrasonic vibration generated from high frequency power supply 582 which are phase shifted by 45°, 90°, 135°, and 180° based on the ultrasonic vibration generated from high frequency power supply 581.

[0059] 7(a) shows a wavefront when ultrasonic vibrations of waveform 101 are emitted from ultrasonic horn 51 and ultrasonic vibrations of waveform 102 are emitted from ultrasonic horn 54. Since the ultrasonic vibrations emitted from ultrasonic horn 54 are ahead of the ultrasonic vibrations emitted from ultrasonic horn 51 in phase by 45°, the phase difference between the two ultrasonic vibrations becomes 0 on the ultrasonic horn 51 side rather than the midpoint (points equidistant) between ultrasonic horn 51 and ultrasonic horn 54, and the ultrasonic vibrations are amplified. For this reason, line SL connecting the points where ultrasonic vibrations are amplified is formed slightly shifted toward ultrasonic horn 51 from the perpendicular bisector of ultrasonic horn 51 and ultrasonic horn 54, which is the line connecting the points where ultrasonic vibrations are amplified when ultrasonic vibrations of the same phase are emitted.

[0060] Fig. 7(b) shows a wavefront when ultrasonic vibrations of waveform 101 are emitted from ultrasonic horn 51, and ultrasonic vibrations of waveform 103 are emitted from ultrasonic horn 54. Fig. 8(a) shows a wavefront when ultrasonic vibrations of waveform 101 are emitted from ultrasonic horn 51, and ultrasonic vibrations of waveform 104 are emitted from ultrasonic horn 54. Fig. 8(b) shows a wavefront when ultrasonic vibrations of waveform 101 are emitted from ultrasonic horn 51, and ultrasonic vibrations of waveform 105 are emitted from ultrasonic horn 54.

[0061] Figures 7 and 8 show that as the ultrasonic vibration emitted from ultrasonic horn 54 leads in phase with respect to the ultrasonic vibration emitted from ultrasonic horn 51, the point at which the phase difference between the two ultrasonic vibrations becomes 0 shifts toward the ultrasonic horn 51, and therefore the line SL connecting the points at which the ultrasonic vibration is amplified is also shifted toward the ultrasonic horn 51.

[0062] In FIG. 8(b) where the phase difference reaches 180°, the ultrasonic vibrations emitted from the ultrasonic horn 51 and the ultrasonic vibrations emitted from the ultrasonic horn 54 are in opposite phase. Comparing FIG. 5, which shows the same phase, with FIG. 8(b), which shows the opposite phase, the solid and dashed lines of the wavefront centered on the ultrasonic horn 54 are inverted, and the points where the ultrasonic vibrations are amplified and attenuated are also exactly opposite. In other words, the constructive points in FIG. 5 become destructive points in FIG. 8, and the destructive points in FIG. 5 become constructive points in FIG. 8. This indicates that by gradually increasing the phase difference, the constructive line SL formed at the midline between the ultrasonic horn 51 and the ultrasonic horn 54 in FIG. 5 gradually moves toward the ultrasonic horn 51, and moves to the position of the destructive line WL that was adjacent to the left of the midline in FIG. 5. Furthermore, by changing the phase by 180° for a total change of 360°, the constructive line SL formed at the midpoint between ultrasonic horn 51 and ultrasonic horn 54 in Fig. 5 moves to the position of the constructive line SL that was adjacent to the midpoint in Fig. 5. In other words, since the constructive line SL moves to the position of the adjacent constructive line SL every time the phase changes by 360°, it is possible to apply amplified ultrasonic vibrations to all of the areas that were between lines SL in Fig. 5.

[0063] As described above, in the burr removal device, the control unit 59 controls the power supply unit 58, and the power control unit 583 controls the power control unit 58 to advance the phase of the high frequency power supplied from the high frequency power supply 582 relative to the phase of the high frequency power supplied from the high frequency power supply 581. As a result, it is possible to advance the phase of the ultrasonic vibration generated from the ultrasonic horn 54 relative to the phase of the ultrasonic vibration generated from the ultrasonic horn 51, as shown in Figures 8 and 9, and as a result, the position at which the ultrasonic vibration is amplified can be shifted toward the ultrasonic horn 51.

[0064] Similarly, by controlling the control unit 59 to control the power supply unit 58 and controlling the power control unit 583 to delay the phase of the high frequency power supplied from the high frequency power supply 582 relative to the phase of the high frequency power supplied from the high frequency power supply 581, it is possible to delay the phase of the ultrasonic vibration emitted from the ultrasonic horn 54 relative to the phase of the ultrasonic vibration emitted from the ultrasonic horn 51, and as a result, it is also possible to shift the position at which the ultrasonic vibration is amplified toward the ultrasonic horn 54.

[0065] In this way, in the burr removal device, the power control unit 583 controls the phase difference of the high frequency power supplied from the high frequency power sources 581 and 582 to the pair of ultrasonic horns, thereby moving the point at which the ultrasonic vibration is amplified in the Y-axis direction between the ultrasonic horn 51 and the ultrasonic horn 54. In particular, by controlling the phase of the high frequency power to gradually give a phase difference and change it by 360° or more, the amplified ultrasonic vibration can be applied to the entire workpiece 1 without omission within the range where the ultrasonic vibration is transmitted. As a result, the amplified ultrasonic vibration is applied to burrs at any position on the workpiece 1, so that the burrs can be reliably removed regardless of the position where the burrs were formed.

[0066] As described above, according to the burr removing device 22 of this embodiment, burrs generated on the workpiece 1 can be efficiently removed by using amplified ultrasonic vibrations. In addition, since the amplified ultrasonic vibrations can be applied to substantially the entire workpiece 1, burrs can be reliably removed from the entire workpiece 1 in a short time without specifying in advance the positions where the burrs are formed (for example, the positions of the streets).

[0067] As mentioned above, applying ultrasonic vibrations is effective in removing burrs, but the resulting effect goes beyond burr removal. After removing the burrs, ultrasonic vibrations have the effect of preventing the removed burrs from adhering to the workpiece 1 again. In addition to removing burrs, ultrasonic vibrations also have a cleaning effect of lifting and removing dirt from the surface of the workpiece 1. In particular, by applying amplified ultrasonic vibrations while moving over the entire workpiece 1, an even greater cleaning effect can be expected than when a constant vibration is applied continuously.

[0068] In this embodiment, an example has been shown in which the ultrasonic horn 51 and the ultrasonic horn 54 are aligned in the Y-axis direction, but the arrangement of the ultrasonic horn 51 and the ultrasonic horn 54 is not particularly limited. For example, they may be aligned in the X-axis direction, or may be aligned in a direction deviating from either the X-axis direction or the Y-axis direction.

[0069] In the present embodiment, the table 27 is rotated in advance by the table rotation motor 32 so that the planned division line 13 of the workpiece 1 faces the X-axis direction and the Y-axis direction, but the direction of the planned division line 13 is not particularly limited. The planned division line 13 may be oriented in a direction deviated from either the X-axis direction or the Y-axis direction.

[0070] In addition, in the present embodiment, an example has been shown in which the ultrasonic horn 51 and the ultrasonic horn 54 have a cylindrical shape, but the shapes of the ultrasonic horn 51 and the ultrasonic horn 54 are not limited to a cylindrical shape as long as they can oscillate ultrasonic vibrations, and for example, it is desirable for the transducer 52 and the horn portion 53 to be in a columnar shape aligned in the height direction.

[0071] Second Embodiment 9 is a cross-sectional view of a portion of a burr removing device 122 according to this embodiment. The configuration of the burr removing device 122 according to this embodiment differs from the configuration of the burr removing device 22 in that an ultrasonic oscillation unit 150 is provided instead of the ultrasonic oscillation unit 50. The other configurations are the same as those of the burr removing device 22.

[0072] The ultrasonic oscillation unit 150 is similar to the ultrasonic oscillation unit 50 in that it includes a plate 501 and a pair of ultrasonic horns (ultrasonic horn 51, ultrasonic horn 54). The ultrasonic oscillation unit 150 is also similar to the ultrasonic oscillation unit 50 in that ultrasonic vibrations whose phase difference changes over time are emitted from the pair of ultrasonic horns.

[0073] The ultrasonic oscillation unit 150 differs from the ultrasonic oscillation unit 50 in that the ultrasonic horn 51 and the ultrasonic horn 54 are disposed on the plate 501 so that the distance between the centers of the ultrasonic horn 51 and the ultrasonic horn 54 is 45 mm. That is, in this embodiment, the distance between the centers of the ultrasonic horn 51 and the ultrasonic horn 54 is about one-fifth of the wafer diameter of 200 mm, and the diameter of the plate 501 supporting the ultrasonic horn 51 and the ultrasonic horn 54 is 85 mm or more, but is less than half the diameter of the workpiece 1 having a diameter of 200 mm.

[0074] In the burr removing device 122 configured as described above, the control unit 59 executes a program to remove burrs using amplified ultrasonic vibrations, similar to the burr removing device 22 according to the first embodiment. However, the burr removing device 122 differs from the burr removing device 22 in that the control unit 59 continues to move the ultrasonic oscillation unit 50 and the table 27 relatively by means of a horizontal movement mechanism in order to apply the amplified ultrasonic vibrations uniformly to the entire workpiece 1, thereby removing burrs from the entire upper surface of the workpiece 1.

[0075] In the following, the point that the amplified ultrasonic vibration is applied uniformly to the entire workpiece 1 using the horizontal movement mechanism will be described.

[0076] In the burr removing device 122, similarly to the burr removing device 22, the positions where the ultrasonic vibrations are reinforced by interference are distributed on the midline (perpendicular bisector) between the ultrasonic horn 51 and the ultrasonic horn 54 and on a hyperbola centered on the midline. In addition, the power control unit 583 controls the phase difference, so that the amplified ultrasonic vibration can be applied to the area located between the lines SL where the ultrasonic vibrations are reinforced in the same phase. However, the sound pressure (intensity) of the ultrasonic vibration is not the same at each position where the ultrasonic vibration is amplified. Since the ultrasonic vibration is attenuated as it travels through the water layer 34, a difference occurs in the sound pressure between a position close to the ultrasonic horn 51 and the ultrasonic horn 54 and a position far away, even if the ultrasonic vibration is the same amplified. Therefore, a difference occurs in the effect of removing the burrs.

[0077] Therefore, the burr removing device 122 applies the amplified ultrasonic vibration uniformly to the entire workpiece 1 by actively using the positions not far from the ultrasonic horn among the positions where the ultrasonic vibrations are reinforced. Specifically, while the ultrasonic oscillation unit 50 is oscillating the ultrasonic vibration, the control unit 59 moves the ultrasonic oscillation unit 50 in the horizontal direction by the horizontal movement mechanism, thereby making the ultrasonic oscillation unit 50 scan the entire upper surface of the workpiece 1. In other words, the ultrasonic oscillation unit 50 is moved relative to the workpiece 1 to sequentially position the ultrasonic oscillation unit 50 above each part of the upper surface of the workpiece 1. This allows the amplified ultrasonic vibration with sufficient sound pressure, which is generated at the positions not far from the ultrasonic horn 51 and the ultrasonic horn 54 among the positions where the ultrasonic vibrations are reinforced, to be applied uniformly to each part of the upper surface of the workpiece 1 in sequence.

[0078] The burr removing device 122 according to this embodiment can also reliably remove burrs from the entire workpiece 1 in a short time without specifying the position where the burr is formed in advance, and other effects are similar to those of the burr removing device 22. Furthermore, the burr removing device 122 can apply ultrasonic vibrations approximately uniformly regardless of the position on the top surface of the workpiece 1, preventing differences in the effect of removing burrs depending on the position. In addition, the fact that ultrasonic vibrations can be applied uniformly makes it possible to suppress the sound pressure of the ultrasonic vibrations generated from the ultrasonic horn to the minimum required for burr removal. Therefore, it is possible to prevent pressure greater than necessary from being applied to the workpiece 1.

[0079] In this embodiment, an example has been shown in which burrs are removed from the workpiece 1 by applying amplified ultrasonic vibrations to the entire surface of the workpiece 1 without specifying in advance the location where the burr is formed. However, the burr removal device 122 may also remove burrs from the entire workpiece 1 by targeting the grooves (kerfs) in which the burrs are formed, line by line, and repeating the operation of removing the burrs formed in the targeted grooves as many times as the number of grooves.

[0080] In this case, the burr removing device 122 first adjusts the planned division line 13 of the work 1 in advance so as to face the X-axis direction and the Y-axis direction, and then adjusts the position of the ultrasonic oscillation unit 50 by controlling the horizontal movement mechanism 55 with the control unit 59 so that the predetermined planned division line 13 extending along the X-axis direction is located at the midpoint of the ultrasonic horn 51 and the ultrasonic horn 54 aligned in the Y-axis direction. In other words, the position of the ultrasonic oscillation unit 50 is adjusted so that the planned division line 13 overlaps with the center line (perpendicular bisector) between the ultrasonic horn 51 and the ultrasonic horn 54, where the phase difference of the ultrasonic vibration becomes 0 and the ultrasonic vibration is amplified. In other words, the center line is positioned directly above the groove D (kerf).

[0081] Thereafter, when adjustment of the position of the ultrasonic oscillation unit 50 is completed, the burr removing device 122 causes the ultrasonic oscillation unit 50 to oscillate ultrasonic vibrations. As a result, the ultrasonic vibrations oscillated from the ultrasonic oscillation unit 50 are amplified on the planned division line 13, and the amplified ultrasonic vibrations act on the burrs generated in the grooves D formed along the planned division line 13.

[0082] Furthermore, the control unit 59 then controls the horizontal movement mechanism 38 to relatively move the ultrasonic oscillation unit 50 and the table 27. That is, the ultrasonic oscillation unit 50 and the table 27 are relatively moved in the X-axis direction. As described above, the ultrasonic vibration is amplified on the division line 13 by positioning the midpoint of the ultrasonic horn 54 on the division line 13, but the amplitude of the amplified ultrasonic vibration differs depending on the position in the X-axis direction on the division line 13. That is, the intensity (sound pressure) of the vibration applied to the burr differs depending on the position in the X-axis direction. Therefore, the burr removing device 122 uses the horizontal movement mechanism 38 to relatively move the ultrasonic oscillation unit 50 and the table 27, thereby averaging the amplitude (i.e., the vibration intensity) that differs depending on the position in the X-axis direction over time, and applies the vibration to the entire burr generated in the groove D regardless of the position in the X-axis direction.

[0083] Thereafter, the control unit 59 changes the planned division line 13 to be scanned and repeats the above-mentioned process for all the planned division lines 13. By using such a method, the burr removing device 122 may remove all burrs generated on the workpiece 1 by cutting processing.

[0084] According to the above method, the burr removing device 122 can apply amplified ultrasonic vibrations evenly to the entirety of a specific division line 13 simply by positioning the division line 13 at the midpoint of the two ultrasonic horns and then moving the ultrasonic oscillation unit 50 along the division line 13. Furthermore, since no complicated position control is required, it is possible to easily scan each division line 13 with amplified ultrasonic vibrations, and burrs can be reliably removed from the kerf.

[0085] In addition, even when the planned division line 13 is positioned at the midpoint between the two ultrasonic horns, the burr removing device 122 generates ultrasonic vibrations whose phase difference changes over time from the ultrasonic horn 51 and the ultrasonic horn 54. That is, the power control unit 583 of the power supply unit 58 is configured to continue changing the phase of the high frequency power supplied by one of the high frequency power supplies 581 and 582 with respect to the phase of the high frequency power supplied by the other high frequency power supply under the control of the control unit 59. The power control unit 583 controls the phase difference of the high frequency power supplied from the high frequency power supplies 581 and 582 to the pair of ultrasonic horns, so that the point at which the ultrasonic vibration is amplified can be moved in the Y-axis direction between the ultrasonic horn 51 and the ultrasonic horn 54. The burr removing device 122 can move the point at which the ultrasonic vibration is amplified in the Y-axis direction relative to the work 1 through the above control performed by the power control unit 583, so that the point at which the ultrasonic vibration is amplified can be moved so as to cross the groove D (kerf). As a result, even if a burr is formed on either edge of a kerf having a certain width, the burr can be reliably removed by applying amplified ultrasonic vibration to the burr.

[0086] The above-mentioned burr removal device 122 may be configured to remove burrs while moving the location on the top surface of the workpiece 1 where the ultrasonic vibrations generated from the two ultrasonic horns are amplified. In this case, the power control by the power control unit 583 may be performed so that the phase difference is continuously changed. In addition to the case where a phase difference that differs in stages is given every predetermined time, the phase difference may be changed continuously at a predetermined speed.

[0087] The phase difference may change in a fixed direction, for example, 0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°, 360°, 45°, etc., or may change in the opposite direction for each revolution, for example, 0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°, 360°, 315°, etc. The point where the ultrasonic vibration is amplified does not necessarily need to scan the entire work 1, but only needs to move to a degree that crosses the kerf, so the phase difference may also change within that range. For this reason, the phase difference may be oscillated within a range of less than 360°, for example, 0°, 45°, 90°, 135°, 90°, 45°, 0°, -45°, -90°, -135°, -90°, etc., and the range in which the phase difference is oscillated may be changed depending on the width of the groove D.

[0088] 10 is a diagram showing wavefronts of ultrasonic waves in phase output from a pair of ultrasonic horns arranged along the planned division line 13, and points where the ultrasonic vibrations in phase interfere with each other and constructive and destructive points. In the above example, the ultrasonic horn 51 and the ultrasonic horn 54 are aligned along the Y-axis direction perpendicular to the planned division line 13 from which burrs are to be removed, but the ultrasonic horn 51 and the ultrasonic horn 54 may be aligned in the X-axis direction along which the planned division line 13 from which burrs are to be removed extends, as shown in FIG.

[0089] Even when the ultrasonic horns 51 and 54 are aligned along the kerf, the intended division line 13 is positioned at the midpoint between the two ultrasonic horns, and then the ultrasonic oscillation unit 50 is simply moved along the intended division line 13, so that the amplified ultrasonic vibration can be applied evenly to the entire specific intended division line 13. In this case, since the line SL connecting the points where the ultrasonic vibration is amplified is positioned so as to cross the kerf, the amplified ultrasonic vibration can be applied regardless of whether a burr is formed on either edge of the kerf.

[0090] Even when the ultrasonic horn 51 and the ultrasonic horn 54 are aligned in the X-axis direction, the ultrasonic horn 51 and the ultrasonic horn 54 may emit ultrasonic vibrations whose phase difference changes over time.

[0091] The embodiments of the present invention are not limited to the above-mentioned embodiments, and may be modified, substituted, or altered in various ways without departing from the spirit of the technical idea of ​​the present invention. Furthermore, if the technical idea of ​​the present invention can be realized in a different way due to technological progress or a different derived technology, the present invention may be implemented using that method. Therefore, the claims cover all embodiments that may be included within the scope of the technical idea of ​​the present invention.

[0092] In the above-described embodiment, an example was shown in which the ultrasonic oscillation unit 50 includes a pair of ultrasonic horns, but multiple pairs of ultrasonic horns may be provided in the ultrasonic oscillation unit 50. When multiple pairs of ultrasonic horns are provided, it is desirable to arrange them so that the ultrasonic vibration from each pair does not excessively attenuate the amplitude at the point where the ultrasonic vibration from the other pairs is amplified, and therefore it is desirable to arrange each pair at a certain distance from each other.

[0093] In the above-described embodiment, two patterns of 100 mm and 45 mm are exemplified for the spacing between the pair of ultrasonic horns included in the ultrasonic oscillation unit 50, but the spacing between the ultrasonic horns is not limited to this example. The spacing between the ultrasonic horns may be within a range of approximately the wafer diameter so long as the ultrasonic horns do not come into contact with each other. In the above-described example, the spacing between the ultrasonic horns may be appropriately changed between, for example, 41 mm and 200 mm.

[0094] In the above embodiment, an example was shown in which the distance from the lower surface of the plate 501 to the upper surface of the wafer was 5 mm, but this distance is not limited to 5 mm and may be set within the range of, for example, 1 mm to 10 mm.

[0095] In the above-described embodiment, an example of removing burrs generated by a cutting blade has been shown, but the burrs that can be removed by the above-described burr removal device are not limited to burrs generated by a specific processing method. The burr removal device is not limited to a cutting blade (cutting device 2), and can also remove burrs generated by a laser processing device 62 shown in FIG. 11. For example, after forming a protective film 35 on the surface AA of the workpiece 1, in order to divide the workpiece 1 into small areas on which the devices 15 are formed, burrs generated by laser processing may be removed by removing the parts of the workpiece 1 corresponding to the planned division lines 13 from the protective film 35 side by laser ablation.

[0096] In addition, the portion of the wafer where the ultrasonic vibration is amplified by the phase difference moves on the wafer's upper surface, which has the effect of cleaning the wafer's upper surface, thereby preventing the removed burrs from remaining on the wafer's upper surface.

[0097] Fig. 11 is a cross-sectional view of a laser processing device 62 according to an embodiment. Hereinafter, as another example of processing the workpiece 1, an example in which a region of the workpiece 1 corresponding to the planned division line 13 is removed from the protective film 35 side formed on the surface AA to form a chip 37 will be described with reference to Fig. 11.

[0098] The protective film 35 is formed by using, for example, a spin coater. The frame set 18 is set on the spin coater with the surface AA of the workpiece 1 facing upward, liquid resin is supplied to the surface AA, the frame set 18 is rotated, and centrifugal force is applied to diffuse the liquid resin, thereby forming the protective film 35.

[0099] The frame set 18 is formed by attaching the workpiece 1 to the tape 41 that covers the opening of the ring-shaped frame 43, and integrating the workpiece 1, the tape 41, and the frame 43. In the frame set 18, unlike the frame set 11, the tape 41 that covers the opening of the frame 43 is attached to the back surface AB of the workpiece 1.

[0100] The raw material of the protective film 35 is not particularly limited, but may be one capable of forming a water-soluble protective film that is resistant to plasma etching, such as water-soluble PVA (polyvinyl alcohol) or PVP (polyvinylpyrrolidone).

[0101] The laser processing apparatus 62 shown in Figure 11 includes a chuck table 64 that holds a workpiece 1 included in the frame set 18, a plurality of clamps 70 that hold a frame 43 included in the frame set 18, and a laser irradiation unit 72 that irradiates a laser beam onto the workpiece 1.

[0102] The chuck table 64 includes a frame 66 having a recess formed on its upper surface, and a holding plate 68 embedded in the recess of the frame 66. A flow path F is formed in the frame 66, which connects the recess of the frame 66 to a suction source (not shown). The holding plate 68 is a porous plate.

[0103] The frame 66 (chuck table 64) is supported by a moving mechanism (not shown), and is moved by the moving mechanism in two directions (the processing feed direction and the indexing feed direction) that are generally parallel to the holding surface G, which is the surface of the holding plate 68, and perpendicular to each other.

[0104] The laser irradiation unit 72 is provided above the chuck table 64. The laser irradiation unit 72 irradiates the workpiece 1 from the protective film 35 side with a laser beam 61 having an absorption wavelength of the workpiece 1, which is oscillated from a pulsed laser with a short pulse width.

[0105] The laser irradiation unit 72 configured as described above first holds the frame set 18 with the protective film 35 facing the laser irradiation unit 72 in order to remove the workpiece 1 from the region corresponding to the planned division line 13 and form the chips 37. Here, a plurality of clamps 70 hold the frame 43. Furthermore, a suction source (not shown) generates negative pressure on the holding surface G by a suction operation, and the chuck table 64 holds the workpiece 1 via the tape 41 by the negative pressure.

[0106] Next, the laser processing device 62 positions the laser irradiation unit 72 in an area corresponding to the planned division line 13. Here, a rotation mechanism supporting the chuck table 64 rotates the chuck table 64 so that the processing feed direction is parallel to the planned division line 13. Next, a movement mechanism supporting the chuck table 64 and moving the chuck table 64 in the processing feed direction and the indexing feed direction moves the chuck table 64 in the indexing feed direction so that the laser irradiation unit 72 is positioned on the area corresponding to the planned division line 13.

[0107] When the laser irradiation unit 72 is positioned over the area corresponding to the planned dividing line 13, the laser processing device 62 irradiates the workpiece 1 with the laser beam 61 emitted from the laser irradiation unit 72 while moving the chuck table 64 in the processing feed direction using the moving mechanism, thereby forming grooves D in the areas corresponding to the planned dividing lines 13 of the workpiece 1 by laser ablation. By repeating the above operation for the areas corresponding to all of the planned dividing lines 13, grooves D are formed along the planned dividing lines 13, and a burr is formed at the upper end of the groove D by melting and cooling through laser ablation.

[0108] The above-mentioned burr removal device can remove burrs generated on the workpiece 1 by laser processing in the same procedure as that for removing burrs generated by the cutting blade 16. The laser processing device 62 and the laser irradiation unit 72 are an example of a dividing means for dividing the workpiece 1 by the laser beam 61 (laser light) to form the chips 37, and the burr removal device is an example of a burr removal device for removing burrs from the workpiece 1 in which a kerf (groove) is formed by the dividing means of the laser beam.

[0109] The above-described burr removal method may include a water layer forming step of forming a water layer 34 between the upper surface of the workpiece 1 and the lower surface of the ultrasonic oscillation unit 50. The water layer 34 may be formed between the upper surface of the workpiece 1 and the lower surface of the ultrasonic oscillation unit 50 by positioning the lower surface of the ultrasonic oscillation unit 50 in the water layer 34 formed on the upper surface of the workpiece 1, or the water layer 34 may be formed between the upper surface of the workpiece 1 and the lower surface of the ultrasonic oscillation unit 50 by arranging the upper surface of the workpiece 1 and the lower surface of the ultrasonic oscillation unit 50 with a gap therebetween and then supplying water into the gap. [Industrial Applicability]

[0110] As described above, the burr removal device of the present invention can remove burrs generated on the workpiece 1 by applying ultrasonic vibrations generated from a pair of ultrasonic horns to the workpiece 1 and amplified ultrasonic vibrations, thereby preventing problems caused by burrs in the processed product. Therefore, it is very useful for removing burrs generated by cutting or laser processing. [Explanation of symbols]

[0111] 1 Work 13 Division line 16 Cutting blade 22, 122 Burr removal device 27 Table 31 Water layer forming part 34 Water layer 38, 55 Horizontal movement mechanism 50, 150 Ultrasonic oscillator unit 51, 54 Ultrasonic horn 58 Power supply section 59 Control section 72 Laser irradiation unit 501 Plate 581, 582 High frequency power supply 583 Power Control Unit D groove

Claims

1. A burr removing device for removing burrs formed in a kerf of a workpiece having a kerf formed therein by a cutting blade or a laser beam, comprising: a table for holding the bottom surface of the workpiece; an ultrasonic oscillation unit arranged on the top surface of the workpiece held on the table with a gap therebetween and for oscillating ultrasonic vibrations against the top surface of the workpiece; and a water layer forming section for forming a water layer between the top surface of the workpiece held on the table and the bottom surface of the ultrasonic oscillation unit, The ultrasonic oscillation unit includes a plate and two cylindrical ultrasonic horns arranged at a distance from each other. The burr removing device further comprises: a horizontal movement mechanism for relatively moving the ultrasonic oscillator unit and the table parallel to an upper surface of the table; a control unit that causes the horizontal movement mechanism to relatively move the ultrasonic oscillation unit and the table; a high frequency power supply that supplies high frequency power to the two ultrasonic horns; a power control unit that keeps changing the phase of the high frequency power supplied from the high frequency power source to one of the ultrasonic horns with respect to the phase of the high frequency power supplied to the other ultrasonic horn, A burr removal device that removes burrs by continuously changing the phase of high-frequency power of one of the two ultrasonic horns, thereby moving the point on the top surface of the workpiece where the ultrasonic vibrations emitted from the two ultrasonic horns are amplified.

2. 2. The burr removing apparatus according to claim 1, wherein the control unit continuously moves the ultrasonic oscillation unit in a horizontal direction to remove burrs from the entire upper surface of the wafer.

3. The two ultrasonic horns are arranged side by side in the X-axis direction which is the extension direction of the kerf, the horizontal movement mechanism includes an X-axis movement mechanism that moves the ultrasonic oscillation unit and the table relatively in the X-axis direction, and a Y-axis movement mechanism that moves the ultrasonic oscillation unit and the table relatively in a Y-axis direction perpendicular to the X-axis direction, 2. The burr removal device according to claim 1, wherein the control unit controls the Y-axis moving mechanism to position the midpoint of the two ultrasonic horns directly above the kerf, and then controls the X-axis moving mechanism to move the ultrasonic oscillation unit along the kerf in the X-axis direction, thereby removing burrs for each kerf.

4. A burr removing method for removing a burr formed in a kerf of a workpiece by a cutting blade or a laser beam by applying ultrasonic vibration from an ultrasonic oscillation unit to the burr, the method comprising: The ultrasonic oscillation unit includes a plate and two spaced apart columnar ultrasonic horns to which high frequency power is supplied from a high frequency power source. a holding step of holding the workpiece on a table; a water layer forming step of forming a water layer between a lower surface of an ultrasonic oscillation unit arranged on the upper surface of the workpiece held on the table with a gap therebetween and the upper surface of the workpiece; a burr removal process in which a location where the ultrasonic vibrations oscillated from the two ultrasonic horns are amplified is moved on the upper surface of the workpiece by continuously changing the phase of the high frequency power supplied by the high frequency power source to one of the ultrasonic horns with respect to the phase of the high frequency power supplied by the high frequency power source to the other ultrasonic horn, and further, the ultrasonic oscillation unit and the table are horizontally moved relative to each other to remove burrs from the entire upper surface of the wafer; The burr removal method comprises:

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