CUTTING DEVICE

Abstract

comprising cutting device (1): a clamping table (3) configured to hold a workpiece (W); a cutting unit (4) with a cutting blade (45) for cutting the workpiece which is held on the clamping table; and a machining feed mechanism configured to move the clamping table (3) and the cutting unit (4) relative to each other for machining; wherein the cutting unit (4) has a spindle (44), wherein the cutting blade (45) is supported at an end section of the spindle, a flange unit (47) comprising a fixed flange (471) attached to an end section of the spindle for supporting the cutting blade and having a plurality of first gas ejection passages (471a) on a circumference thereof for ejecting gas radially along a cutting edge (45a) of the cutting blade, and a removable flange (472) sandwiching the cutting blade in cooperation with the fixed flange (471) and having a plurality of second gas ejection passages (472a) on a circumference thereof for ejecting gas radially along the cutting edge (45a) of the cutting blade, a cover (42) that covers the cutting blade (45) and the flange unit (47), and a vacuum unit (43) provided on the cover and configured to extract dust scattered inside the cover.

Description

BACKGROUND OF THE INVENTIONTechnical field

[0001] The present invention relates to a cutting device including a chuck table, a cutting unit having a rotatable cutting blade that cuts a workpiece held on the chuck table, and a machining feed mechanism that conveys the chuck table and the cutting unit relative to each other for machining. Description of the related art

[0002] A wafer, on whose surface a plurality of components, such as integrated circuits (ICs) or large-scale integration (LSI), are formed, defined by a plurality of intersecting, planned division lines, is divided into individual component chips by a device. The divided component chips are used in electronic devices such as mobile phones or personal computers.

[0003] A well-known dicing device includes a chuck table that holds a workpiece, a cutting unit that cuts the workpiece held on the chuck table while supplying cutting water to the workpiece, and a machining feed mechanism that conveys the chuck table and the cutting unit relative to each other for machining. The dicing device can remove dust generated from a cut part and cool a cutting area using the cutting water, and divide the wafer held as the workpiece into individual component chips with high precision (see, for example, JP 2010-50214 A).

[0004] The documents DE 10 2017 209 189 A1 and US 2016 / 0 311 127 A1 represent further prior art. PRESENTATION OF THE INVENTION

[0005] Some wafers to be cut with the dicing device have a layer on the surface formed from a substance whose machinability could be reduced by the cutting water, such as raw ceramic (ceramic before sintering). The dicing device using the cutting water as described above is unsuitable for cutting such a workpiece. Furthermore, machining heat caused by friction occurs when cutting the workpiece with the cutting blade. If cutting is performed without the use of cutting water, it is not possible to adequately cool the cutting blade and workpiece while removing the dust, so the machining quality deteriorates.

[0006] Accordingly, it is an object of the present invention to provide a cutting device that can adequately cool the cutting blade and the workpiece while removing the dust scattered from the cut part without the use of cutting water.

[0007] According to one aspect of the present invention, a cutting device is provided, comprising: a chuck table configured to hold a workpiece; a cutting unit having a cutting blade for cutting the workpiece held on the chuck table; and a machining feed mechanism configured to convey the chuck table and the cutting unit relative to each other for machining. The cutting unit includes a spindle, the cutting blade being supported on an end portion of the spindle; a flange unit; a cover covering the cutting blade and the flange unit; and a vacuum unit provided on the cover and configured to suck dust scattered inside the cover.The flange unit includes a fixed flange fixed to an end portion of the spindle for supporting the cutting blade and having a plurality of first gas ejection passages on a circumference thereof for ejecting gas radially along a cutting edge of the cutting blade, and a detachable flange sandwiching the cutting blade in cooperation with the fixed flange and having a plurality of second gas ejection passages on a circumference thereof for ejecting gas radially along the cutting edge of the cutting blade.

[0008] Preferably, the cover includes a gas ejection nozzle for ejecting gas to an area where the cutting blade cuts the workpiece. Preferably, the gas is one of air, N2, CO2, and dry mist, or a combination thereof.

[0009] In the present invention, without the use of cutting water, dust scattered inside the cover is extracted from the inside of the cover, and the cutting edge of the cutting blade and the workpiece are cooled. Thus, even a workpiece made of a material whose machinability might be reduced due to cutting water can be cut while being adequately cooled, thus maintaining the machining quality.

[0010] The above and other objects, features and advantages of the present invention and the mode for carrying them out will become more apparent from, and the invention itself will be best understood by, a study of the following description and the appended claims with reference to the accompanying drawings which show a preferred embodiment of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a general perspective view of a cutting device according to an embodiment of the present invention; Fig. 2A is a perspective view of a cutting unit used in the Fig. 1 shown cutting device is arranged; Fig. 2B is an exploded perspective view of the Fig. 2A shown cutting unit; Fig. 3A is an exploded perspective view of a configuration in which a cover of the Fig. 2B shown cutting unit is removed; Fig. 3B is a sectional view showing the Fig. 3A is cut along an arrangement direction of a spindle; Fig. 4A is a sectional view of a state in which the cutting unit of Fig. 3B performs a cutting step; and Fig. Figure 4B is a conceptual diagram showing a section of a portion of the cutting unit in side view. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A cutting device according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0012] Fig. 1 illustrates a cutting apparatus 1 according to the present embodiment. The cutting apparatus 1 in the present embodiment has an apparatus body 2 having a substantially rectangular parallelepiped shape. The cutting apparatus 1 includes a chuck table mechanism 3 arranged as a holding unit and holding a wafer W as a workpiece, and a cutting unit 4 rotatably having a cutting blade that cuts the wafer W held by the chuck table mechanism 3. In the present embodiment, the wafer W to be processed is, for example, a wafer on top of which a green ceramic layer is formed and which is supported by an annular frame F via an adhesive tape T.

[0013] The cutting device 1 includes a cassette 5 (indicated by a double-dashed chain line) that accommodates a plurality of wafers W as workpieces, a temporary placement table 6 on which a wafer W unloaded from the cassette 5 is temporarily placed, a loading and unloading mechanism 7 that unloads the wafer W from the cassette 5 onto the temporary placement table 6, a transport mechanism 8 that rotates to transport the wafer W unloaded onto the temporary placement table 6 onto a suction chuck 3a of the chuck table mechanism 3, a cleaning unit 9 (details are not shown) for cleaning the wafer W cut by the cutting unit 4, a cleaning transport mechanism 11 that transports the cut wafer W from the suction chuck 3a of the chuck table mechanism 3 to the cleaning unit 9, and an imaging unit 12 that images the wafer W on the suction chuck 3a.and a control unit (not shown). The cassette 5 is mounted on a cassette table 5a, which is arranged to be vertically movable by a lifting and lowering means (not shown). The height of the cassette 5 is appropriately adjusted when the loading and unloading mechanism 7 unloads a wafer W from the cassette 5.

[0014] In the interior of the device body 2, there is a machining feed mechanism (not shown) which is a means for machining feed of the chuck table mechanism 3 and the cutting unit 4 relative to each other and which moves the chuck table mechanism 3 in an X-axis direction indicated by an arrow X as a cutting feed direction.

[0015] The cutting unit 4 described above is described with reference to the Fig. 2A to 3B are described in more detail. Fig. Figure 2A shows the main parts of the cutting unit 4 on an enlarged scale. Fig. Figure 2B is a perspective view showing a part of the Fig. 2A shown cutting unit 4 is disassembled. In addition, Fig. 3A represents a condition in which the Fig. 2A and Fig. 2B, the cutting unit 4 is further disassembled, with a cover 42 of the cutting unit 4 being omitted for ease of description. Fig. Figure 3B is a sectional view showing the Fig. 3A is cut along an arrangement direction of a spindle 44.

[0016] As from Fig. 2A and Fig. 2B, the cutting unit 4 includes a spindle housing 41 extending in a Y-axis direction indicated by an arrow Y, the spindle 44 rotatably supported by the spindle housing 41, an annular cutting blade 45 detachably supported on an end portion of the spindle 44, the cover 42 attached to one end of the spindle housing 41 and covering the cutting blade 45 and a flange unit 47 to be described later, a vacuum unit 43 provided on the cover 42 and sucking dust scattered inside the cover 42, and a nut 46 for fixing the cutting blade 45 to a distal end portion of the spindle 44 in cooperation with the flange unit 47. In addition, the spindle 44 is rotated by an unillustrated electric motor in a direction indicated by an arrow R1. In addition, the cutting unit 4 is equipped with a movement mechanism not shown.The moving mechanism includes an indexing feed mechanism that moves the cutting unit 4 in the Y-axis direction indicated by the arrow Y for indexing, and a cutting feed mechanism capable of moving the cutting unit 4 in a Z-axis direction (up-down direction) indicated by an arrow Z and moving the cutting unit 4 downward for cutting.

[0017] As in Fig. As shown in Fig. 2B, the cover 42 includes a first cover member 42a fixed to the spindle housing 41, a second cover member 42b fixed to the first cover member 42a by a screw 42e screwed into a threaded hole 42h defined in a front surface of the first cover member 42a, and a blade detection block 42c fixed to the first cover member 42a by a screw 42f screwed from above into a threaded hole 42i defined in an upper surface of the first cover member 42a. A blade sensor (not shown) for detecting wear or chipping in a cutting blade portion 45a on the peripheral edge portion side of the cutting blade 45 is disposed in the blade detection block 42c. The vacuum unit 43 is attached to the cover 42.The vacuum unit 43 is arranged in a direction in which dust containing cutting waste is scattered inside the cover 42 that accommodates the cutting blade 45 when the cutting blade 45 is rotated, for example, in the direction shown by the arrow R1 in FIG. Fig. 2B. The suction unit 43 sucks in the dust and expels it to the outside. The dust is then collected by a filter or the like (not shown). The suction unit 43 has an outlet opening 43a formed by a flexible hose connected to a suction means (not shown), and a suction opening 43b opening toward the inside of the cover 42 and sucking in the dust.

[0018] As from Fig. 3A, the flange unit 47 is arranged at an end portion of the spindle 44. The flange unit 47 includes a fixed flange 471 and a detachable flange 472. The fixed flange 471 is fixed to the end portion of the spindle 44 for supporting the cutting blade 45 and has a plurality of gas discharge passages 471a for discharging gas radially along the cutting edge 45a, which forms the peripheral side of the cutting blade 45. The detachable flange 472 is configured to be detachable from the spindle 44 and sandwich the cutting blade 45 in cooperation with the fixed flange 471. The detachable flange 472 has on its periphery a plurality of discharge passages 472a for discharging gas in the radial direction along the cutting edge 45a, which forms the peripheral side of the cutting blade 45. Furthermore, even if Fig. 3A does not represent the entirety of the ejection passages 472a provided on the detachable flange 472, the ejection passages 472a are formed in a similar manner to the ejection passages 471a of the fixed flange 471 arranged to oppose the detachable flange 472.

[0019] At the end portion of the spindle 44, an external thread 44a is formed on a peripheral surface at a further distal end side with respect to the fixed flange 471. In addition, as shown in Fig. 3A and Fig. 3B, a gas inlet opening 49 is formed in the spindle housing 41. The gas inlet opening 49 is connected to a gas supply device (not shown). High-pressure gas (e.g., 0.3 to 0.5 MPa) is introduced from the gas supply device into the spindle housing 41 via the gas inlet opening 49. The gas introduced via the gas inlet opening 49 is preferably one of air, nitrogen (N2), carbon dioxide (CO2), and dry mist, or a combination thereof. As shown in Fig. As shown in Figure 3B, an annular groove 44b is formed at a position opposite the gas introduction port 49 in the peripheral surface of the spindle 44, which is rotatably supported by the spindle housing 41. A communication passage 44d is formed inside the spindle 44, extending along a longitudinal direction of the spindle 44. A plurality of holes 44c formed in the annular groove 44b are connected to the communication passage 44d.

[0020] In addition, at the end portion of the spindle 44, an annular groove 44e is formed in the circumferential surface between the fixed flange 471 and the external thread 44a. A plurality of holes 44f, for example, six holes 44f, which allow the above-described communication passage 44d and the annular groove 44e to communicate with each other, are formed at equal intervals in a bottom portion of the annular groove 44e. In addition, as shown in Fig. 3A, a protruding portion 44g having a height corresponding to the depth of the annular groove 44e is formed at an intermediate position between adjacent holes 44f at the bottom portion of the annular groove 44e. The protruding portion 44g is formed at a plurality of positions at equal intervals in the annular groove 44e. In the present embodiment, the number of protruding portions 44g is the same (six) as the number of holes 44f. As shown in Fig. 3B, the cutting blade 45 is positioned at the annular groove 44e (see also Fig. 4A), by positioning an opening portion 45b of the cutting blade 45 from the distal end side (left in the figure) of the spindle 44 to attach the cutting blade 45 in a direction indicated by an arrow R2, and causing the cutting blade 45 to abut against the fixed flange 471, thereby fixing the cutting blade 45 to the end portion of the spindle 44. At this time, the opening portion 45b of the cutting blade 45 abuts against and is supported by the above-described protruding portions 44g. Further, an opening portion 472b of the detachable flange 472 is positioned and attached to the distal end side of the spindle 44, and an internal thread 46a of the nut 46 is screwed and fastened to the external thread 44a of the spindle 44.The cutting blade 45 is thus sandwiched and fixed by the surface of the fixed flange 471 having the ejection passages 471a formed thereon and the surface of the detachable flange 472 having the ejection passages 472a formed thereon.

[0021] In the cutting unit 4, which is configured as described above, as in Fig. As shown in Fig. 4A, when high-pressure gas G is supplied via the gas introduction port 49 of the spindle housing 41, the gas G is passed through the annular groove 44b, the holes 44c, the communication passage 44d, the holes 44f, and the annular groove 44e of the spindle 44, and is introduced into the discharge passages 471a of the fixed flange 471 and the discharge passages 472a of the detachable flange 472. Thus, the gas G can be discharged radially along the cutting edge 45a of the cutting blade 45.

[0022] The cutting device 1 according to the present embodiment generally has the configuration described above. The actions and effects of the cutting device 1 will be described below.

[0023] In the with reference to Fig. In the cutting device 1 described in FIG. 1, when a cutting step for cutting the wafer W as described above is to be performed, a wafer W taken out from the cassette 5 is transported and placed on the suction chuck 3a of the chuck table mechanism 3, and held under suction by the suction chuck 3a. After the wafer W is held under suction by the suction chuck 3a, the chuck table mechanism 3 is positioned directly under the above-described imaging unit 12 by operating the above-described processing feed mechanism, the wafer W is imaged, and an alignment step is performed.Next, the wafer W is positioned directly below the cutting unit 4 by moving the chuck table mechanism 3 based on position information of a position to be processed on the wafer W, for example, a planned dividing line (not shown) detected in the alignment step.

[0024] After the wafer W is positioned directly under the cutting unit 4, a predetermined planned dividing line extending in a first direction of the wafer W is adjusted to the X-axis direction, and an alignment between the predetermined planned dividing line and the cutting blade 45 described above is performed. Next, as shown in Fig. 4B, the cutting blade 45, which is rotated at high speed in a direction indicated by an arrow R1, is positioned on the planned parting line aligned with the X-axis direction, the cutting blade 45 is caused to cut into the wafer W by a predetermined depth from one side of the upper surface Wa, and the chuck table mechanism 3 is moved in a direction indicated by an arrow X. Thus, a cutting groove 100 is formed. At this time, the cutting groove 100 formed by the Fig. 4A is introduced into the interior of the spindle 44 via the communication passage 44d, guided to the discharge passages 471a formed on the fixed flange 471 and the discharge passages 472a formed on the detachable flange 472, and discharged radially along the cutting edge 45a of the cutting blade 45, as shown in Fig. 4B. The gas G discharged radially along the cutting edge 45a of the cutting blade 45 is sucked into the suction port 43b of the vacuum unit 43 and discharged to the outside from the discharge port 43a, along with dust D containing cutting debris generated during cutting. The dust D discharged from the discharge port 43a is collected by a filter or the like (not shown).

[0025] After the cut groove 100 is formed as described above, the cutting blade 45 of the cutting unit 4 is guided for indexing to another planned parting line extending in the first direction, which is adjacent to the cut groove 100 and in which no cut groove 100 is formed. Then, cutting processing in which a cut groove 100 is formed is performed in a similar manner to that described above. By repeating the above processing, cut grooves 100 are formed along all the planned parting lines extending in the first direction.Next, the wafer W is rotated 90 degrees together with the chuck table mechanism 3, a planned dividing line extending in a second direction orthogonal to the first direction in which the cutting grooves 100 were formed is aligned with the X-axis direction, and the above-described cutting processing is performed for all planned dividing lines newly aligned with the X-axis direction. Thus, the cutting grooves 100 are formed along all the planned dividing lines formed on the wafer W (cutting step).

[0026] With the cutting apparatus according to the present embodiment, a dry-type system that does not use cutting water can exhaust the dust D scattered inside the cover 42 through the vacuum unit 43 together with the above-described gas G from the inside of the cover 42, and cool the cutting edge 45a of the cutting blade 45 and the wafer W as a workpiece. Thus, even a workpiece made of a material whose machinability might be degraded by the above-described cutting water can be appropriately cut, maintaining the machining quality.

[0027] Furthermore, as in Fig. 4B, the cover 42 of the cutting unit 4 of the cutting apparatus 1 according to the present embodiment is provided with a gas ejection nozzle 42k that ejects gas G into a region where the cutting blade 45 cuts the wafer W. More specifically, the gas ejection nozzle 42k is arranged at a position opposite to the vacuum unit 43 with the cutting blade 45 interposed therebetween; it is caused to communicate with a gas introduction passage 42j formed inside the first cover member 42a and with a gas introduction port 42d (see also Fig. 2A and Fig.2B) defined in the upper surface of the first cover member 42a; and is connected to a gas supply device (not shown). When the gas G supplied from the gas supply device is discharged from the gas discharge nozzle 42k, the dust D generated during the cutting step is more efficiently guided to and sucked away by the vacuum unit 43, and the cutting edge 45a of the cutting blade 45 and the wafer W as a workpiece are more efficiently cooled.

[0028] Furthermore, in the above embodiment, the same gas G as the above-described gas G introduced from the gas introduction port 49 formed in the spindle housing 41 is selected as the gas G introduced from the gas introduction port 42d formed in the upper surface of the first cover member 42a. However, the present invention is not limited to this, and other types of gas may also be selected. For example, a dry mist may be selected as the gas G introduced from the gas introduction port 49 formed in the spindle housing 41 and jetted radially along the cutting edge 45a of the cutting blade 45, while nitrogen (N2) may be selected as the gas G jetted from the gas jet nozzle 42k and jetted into the area where the cutting blade 45 cuts the wafer W.

Claims

[1] Cutting device (1) comprising: a clamping table (3) configured to hold a workpiece (W); a cutting unit (4) having a cutting blade (45) for cutting the workpiece held on the clamping table; and a machining feed mechanism configured to move the chuck table (3) and the cutting unit (4) relative to each other for machining; wherein the cutting unit (4) has a spindle (44), wherein the cutting blade (45) is supported on an end portion of the spindle, a flange unit (47) including a fixed flange (471) fixed to an end portion of the spindle for supporting the cutting blade and having a plurality of first gas ejection passages (471a) on a periphery thereof for ejecting gas radially along a cutting edge (45a) of the cutting blade, and a detachable flange (472) sandwiching the cutting blade in cooperation with the fixed flange (471) and having a plurality of second gas ejection passages (472a) on a periphery thereof for ejecting gas radially along the cutting edge (45a) of the cutting blade, a cover (42) covering the cutting blade (45) and the flange unit (47), and a vacuum unit (43) provided on the cover and configured to suck dust scattered inside the cover. [2] The cutting device (1) according to claim 1, wherein the cover has a gas ejection nozzle (42k) for ejecting gas to a region where the cutting blade (45) cuts the workpiece. [3] Cutting device (1) according to claim 1, wherein the gas is one of air, N2, CO2 and dry mist or a combination thereof.

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