Cutting device

Abstract

To provide a cutting device configured so as to prevent chips from remaining in cut grooves.SOLUTION: A cutting device includes holding means that holds a work-piece, cutting means 6 rotatably comprising a cutting blade 20 that cuts the work-piece held by the holding means, and processing water supply means 8. The processed water supply means 8 comprises an air bubble mixing part 24 that mixes air bubbles in processing water and a nozzle part 26 that sprays the processing water having the air bubbles mixed therein, by air. The nozzle part 26 is arranged in a region where the work-piece held by the holding means is cut with the cutting blade 20.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a cutting device including holding means for holding a workpiece, cutting means rotatably provided with a cutting blade for cutting the workpiece held by the holding means, and machining water supply means.

Background Art

[0002] A wafer on which a plurality of devices such as ICs and LSIs are partitioned by a division planned line and formed on the surface is divided into individual device chips by a cutting device, and each divided device chip is used in electrical devices such as mobile phones and personal computers.

[0003] The cutting device includes holding means for holding a wafer, cutting means rotatably provided with a cutting blade for cutting the wafer held by the holding means, feeding means for relatively machining and feeding the holding means and the cutting means, and alignment means for imaging the wafer held by the holding means and detecting a division planned line to be cut, and can divide the wafer into individual device chips with high precision (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the width of the cutting groove cut by the cutting blade is extremely narrow, around 50 μm, and there are cases where even if cutting water is jetted into the cutting area with high-pressure air, the cutting chips that have entered the cutting groove cannot be sufficiently removed. In such a case, when picking up the device chip and bonding it to the wiring board, there arises a problem that the cutting chips remaining in the cutting groove fall off and deteriorate the quality of the electronic component.

[0006] An object of the present invention is to provide a cutting device in which cutting chips do not remain in the cutting groove.

Means for Solving the Problems

[0007] According to the present invention, the following cutting device for solving the above problems is provided. That is, “A cutting device including a holding means for holding a workpiece, a cutting means rotatably provided with a cutting blade for cutting the workpiece held by the holding means, and a machining water supply means, The machining water supply means includes a bubble mixing portion for mixing bubbles into the machining water, and a nozzle portion for injecting the machining water mixed with bubbles with air, The nozzle portion is disposed in a region where the workpiece held by the holding means is cut with the cutting blade” is provided.

[0008] Preferably, it includes a spinner table that holds and rotatably holds the machined workpiece, and a cleaning means for cleaning the workpiece held by the spinner table. The cleaning means is disposed in a region where the nozzle portion of the machining water supply means faces the workpiece held by the spinner table. The diameter of the bubbles mixed into the machining water by the bubble mixing portion is preferably less than 1 μm.

Effects of the Invention

[0009] The cutting device of the present invention is A cutting device including a holding means for holding a workpiece, a cutting means rotatably provided with a cutting blade for cutting the workpiece held by the holding means, and a machining water supply means, The machining water supply means includes a bubble mixing portion for mixing bubbles into the machining water, and a nozzle portion for injecting the machining water mixed with bubbles with air, Since the nozzle portion is disposed in a region where the workpiece held by the holding means is cut with the cutting blade, no cutting chips remain in the cutting groove.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0011] Hereinafter, a preferred embodiment of the cutting device according to the present invention will be described with reference to the drawings.

[0012] (Cutting device 2) In FIG. 1, the cutting device, indicated as a whole by reference numeral 2, includes a holding means 4 for holding a workpiece such as a wafer W, a cutting means 6 rotatably provided with a cutting blade for cutting the workpiece held by the holding means 4, and a processing water supply means 8. Note that the wafer W shown in FIG. 1 is attached to a dicing tape T whose periphery is fixed to an annular frame F. Further, as shown in FIG. 2, the surface Wa of the wafer W is partitioned into a plurality of rectangular regions by grid-like division planned lines L, and devices D such as ICs and LSIs are formed in each rectangular region.

[0013] (Holding means 4) As shown in Fig. 1, the holding means 4 has a chuck table 10 that is movable in the X-axis direction and rotatable about the Z-axis. Although not shown, the chuck table 10 is fed in the machining feed direction in the X-axis direction by a ball screw type X-axis feed means. Further, the chuck table 10 is rotated about the Z-axis by a motor (not shown). Note that the X-axis direction is the direction indicated by arrow X in Fig. 1, and the Z-axis direction is the vertical direction that is orthogonal to the X-axis direction and is indicated by arrow Z in Fig. 1. Also, the Y-axis direction indicated by arrow Y in Fig. 2 is the direction orthogonal to the X-axis direction and the Z-axis direction. The XY plane defined by the X-axis direction and the Y-axis direction is substantially horizontal.

[0014] A circular suction chuck 12 is disposed at the upper end portion of the chuck table 10 of the holding means 4. The suction chuck 12 is formed of a porous member such as porous ceramics. Further, the suction chuck 12 is connected to a suction means (not shown). In the holding means 4, a suction force is generated on the upper surface of the suction chuck 12 by the suction means, and the workpiece placed on the upper surface of the suction chuck 12 is suction-held. Also, a plurality of clamps 14 for fixing the annular frame F are arranged at intervals in the circumferential direction on the periphery of the chuck table 10.

[0015] (Cutting means 6) Referring to Fig. 2 for explanation, the cutting means 6 includes a spindle housing 16 that is movable in the Y-axis direction and the Z-axis direction, a spindle 18 that is rotatably supported by the spindle housing 16, an annular cutting blade 20 mounted at the tip of the spindle 18, and a blade cover 22 that covers the cutting blade 20. Although not shown, the spindle housing 16 is fed in the indexing feed direction in the Y-axis direction by a ball screw type Y-axis feed means and is fed in the cutting feed direction in the Z-axis direction by a ball screw type Z-axis feed means. Also, the cutting edge of the cutting blade 20 is formed to a predetermined thickness (for example, about 50 μm) from abrasive grains such as diamond and a binder such as metal or resin.

[0016] (Processing water supply means 8) As shown in FIG. 2, the machining water supply means 8 includes a bubble mixing portion 24 that mixes bubbles into the machining water, and a nozzle portion 26 that injects the machining water with bubbles mixed therein by air. The nozzle portion 26 of the present embodiment has a first nozzle portion 26a and a second nozzle portion 26b.

[0017] (Bubble mixing portion 24) The bubble mixing portion 24 mixes fine bubbles into the machining water (for example, pure water) supplied from the machining water supply source 28. The diameter of the bubbles mixed into the machining water by the bubble mixing portion 24 is smaller than the width of the cutting groove formed in the workpiece by the cutting blade 20, for example, less than 1 μm. Since the bubble mixing portion 24 may be a known bubble generating means, the description of the configuration is omitted. A pressurizing portion 30 is provided on the downstream side of the bubble mixing portion 24, and high-pressure air (for example, air of about 0.5 MPa) is supplied to the pressurizing portion 30 from a high-pressure air source 32. Further, a first on-off valve 36 is installed in a pipeline 34 connecting the pressurizing portion 30 and the first nozzle portion 26a.

[0018] (First nozzle portion 26a) The first nozzle portion 26a is disposed in a region where the workpiece held by the holding means 4 is cut by the cutting blade 20. The first nozzle portion 26a of the present embodiment includes a pair of supply ports 38 provided on the upper portion of the blade cover 22 and a pair of injection nozzles 40 (only one side is shown) provided on the lower portion of the blade cover 22. The pair of supply ports 38 are connected to the pair of injection nozzles 40 via a flow path (not shown) inside the blade cover 22. The pair of injection nozzles 40 are arranged at intervals in the Y-axis direction with the cutting blade 20 interposed therebetween. Further, a plurality of injection ports (not shown) are formed in the injection nozzles 40 at intervals in the X-axis direction.

[0019] Then, in the machining water supply means 8, machining water is supplied from the machining water supply source 28 to the air bubble mixing section 24. Next, after air bubbles are mixed into the machining water in the air bubble mixing section 24, the machining water with air bubbles mixed therein is pressurized in the pressurizing section 30 by the high-pressure air supplied from the high-pressure air source 32, and the machining water with air bubbles mixed therein is jetted together with air from the jet ports of the pair of injection nozzles 40. That is, the bubble-mixed machining water and air (two fluids) are jetted from the jet ports of the pair of injection nozzles 40 to the area where the workpiece held by the holding means 4 is cut by the cutting blade 20.

[0020] Referring to FIGS. 2 and 3 for explanation, the cutting apparatus 2 further includes a spinner table 42 that can hold and rotate the machined workpiece, and a cleaning means 44 that cleans the workpiece held by the spinner table 42.

[0021] (Spinner table 42) As shown in FIG. 3, a circular suction chuck 46 is disposed at the upper end portion of the spinner table 42. The suction chuck 46 is formed of a porous member such as porous ceramics. Further, the suction chuck 46 is connected to a suction means (not shown). In the spinner table 42, a suction force is generated on the upper surface of the suction chuck 46 by the suction means, and the workpiece placed on the upper surface of the suction chuck 46 is suction-held.

[0022] At the center of the spinner table 42, a rotary shaft 48a of a motor 48 for rotating the spinner table 42 is connected. The motor 48 rotates the spinner table 42 about the vertical axis. Further, an elevating means 50 that can be constituted by an actuator such as an air cylinder is mounted on the outer peripheral surface of the motor 48. The elevating means 50 elevates the spinner table 42 between the ascending position (the position shown in FIG. 3) where the workpiece is attached and detached and the descending position (the position shown in FIG. 4) where the workpiece is cleaned.

[0023] (Cleaning means 44, second nozzle section 26b) The cleaning means 44 includes the second nozzle portion 26b, and the second nozzle portion 26b is disposed in a region facing the workpiece held by the spinner table 42. As shown in FIGS. 3 and 4, the injection port 26b' of the second nozzle portion 26b is disposed above the workpiece held by the spinner table 42. Further, a turning motor 52 (see FIG. 2) is attached to the second nozzle portion 26b. The second nozzle portion 26b is turned by the turning motor 52, so that it is positioned at a standby position (the position shown in FIG. 3) where the injection port 26b' is separated from directly above the spinner table 42 and an injection position (the position shown in FIG. 4) where the injection port 26b' is positioned above the central portion of the spinner table 42.

[0024] As shown in FIG. 2, a second on-off valve 56 is installed in a pipeline 54 connecting the second nozzle portion 26b and the pressurizing portion 30. Then, air-bubble mixed machining water and air (two fluids) are injected from the injection port 26b' of the second nozzle portion 26b toward the workpiece held by the spinner table 42.

[0025] Also, as shown in FIGS. 2 and 3, the cleaning means 44 includes an air nozzle 58 that injects dry air toward the workpiece held by the spinner table 42, a turning motor 60 (see FIG. 2) that turns the air nozzle 58, a drain pan 62 that receives the air-bubble mixed machining water injected from the second nozzle portion 26b, and a drain hose 64 (see FIG. 3) attached to the drain pan 62. The injection port 58' of the air nozzle 58 is disposed above the workpiece held by the spinner table 42. The air nozzle 58 is turned by the turning motor 60, so that it is positioned at a standby position (the position shown in FIG. 3) where the injection port 58' is separated from directly above the spinner table 42 and an injection position where the injection port 58' is positioned above the central portion of the spinner table 42. Further, the drain pan 62 surrounds the spinner table 42, and the air-bubble mixed machining water (cleaning water) received by the drain pan 62 is discharged through the drain hose 64.

[0026] As shown in FIG. 1, the cutting apparatus 2 further includes a vertically movable cassette table 68 on which a cassette 66 containing a plurality of workpieces such as a wafer W is placed, a loading / unloading means 72 that withdraws the workpiece before cutting from the cassette 66, transports it to a temporary placement table 70, and loads the cut workpiece positioned on the temporary placement table 70 into the cassette 66, a first transport means 74 that transports the workpiece before cutting withdrawn from the cassette 66 to the chuck table 10 of the holding means 4, an imaging means 76 that images the workpiece held by the chuck table 10, and a second transport means 78 that transports the cut workpiece from the chuck table 10 to a spinner table 42.

[0027] Next, a cutting method for cutting a wafer W as a workpiece using the above-described cutting apparatus 2 will be described.

[0028] (Holding step) In the present embodiment, first, a holding step is performed in which the wafer W is transported from the cassette 66 to the chuck table 10 and the wafer W is held on the chuck table 10.

[0029] In the holding step, first, the wafer W before cutting is unloaded from the cassette 66 to the temporary placement table 70 by the loading / unloading means 72. Next, the wafer W is transported from the temporary placement table 70 to the chuck table 10 positioned at the delivery position (the position shown in FIG. 1) by the first transport means 74, and the wafer W is placed on the upper surface of the chuck table 10. Next, suction force is generated in the suction chuck 12 of the chuck table 10 to suck and hold the wafer W on the chuck table 10. Further, an annular frame F supporting the wafer W via a dicing tape T is fixed by a plurality of clamps 14.

[0030] (Cutting step) After performing the holding step, a cutting step is performed in which the wafer W is subjected to cutting by the cutting blade 20 of the cutting means 6.

[0031] In the cutting process, first, the planned division line L of the wafer W is aligned in the X-axis direction. At this time, the chuck table 10 is moved directly below the imaging means 76 by the X-axis feed means, and the wafer W is imaged by the imaging means 76. Then, based on the image of the wafer W captured by the imaging means 76, the chuck table 10 is appropriately rotated to align the planned division line L of the wafer W in the X-axis direction.

[0032] After aligning the planned division line L in the X-axis direction, cutting is performed along the planned division line L of the wafer W. At this time, the chuck table 10 is moved below the cutting means 6 by the X-axis feed means. Also, the cutting blade 20 is rotated in the direction indicated by the arrow R1 in FIG. 2. Then, the cutting blade 20 is lowered by the Z-axis feed means, and the cutting edge of the cutting blade 20 is cut into the upper surface of the wafer W to a predetermined depth, and the chuck table 10 is fed in the X-axis direction by the X-axis feed means for cutting feed. In this way, cutting is performed along the planned division line L of the wafer W. The cutting groove formed in the wafer W by the cutting is indicated by reference numeral 80 in FIG. 2. The width of the cutting groove 80 is, for example, about 50 μm. Also, while indexing and feeding the cutting blade 20 in the Y-axis direction by the Y-axis feed means by the interval in the Y-axis direction of the planned division line L, the cutting process is repeated to perform cutting on all of the planned division lines L aligned in the X-axis direction. After that, after rotating the chuck table 10 by 90 degrees, the cutting process and the indexing feed are repeated to perform cutting on all of the planned division lines L orthogonal to the planned division line L on which the cutting process was previously performed.

[0033] When performing cutting, bubble-mixed machining water and air (two fluids) are injected into the area of the wafer W to be cut by the cutting blade 20. That is, machining water is supplied from the machining water supply source 28 to the bubble mixing section 24, and bubbles are mixed into the machining water by the bubble mixing section 24. The bubble-mixed machining water is pressurized in the pressurizing section 30 by high-pressure air (for example, air at about 0.5 MPa) supplied from the high-pressure air source 32. Then, the first on-off valve 36 is opened, and the bubble-mixed machining water and air are injected from the injection ports of the pair of injection nozzles 40. Then, since the bubbles mixed in the machining water are pushed into the cutting groove 80 by the air, the bubbles capture the cutting chips in the cutting groove 80. The captured cutting chips float to the upper part of the cutting groove 80 together with the bubbles and are removed from the wafer W by the machining water and air injected from the pair of injection nozzles 40. Therefore, according to the present embodiment, since no cutting chips remain in the cutting groove 80, when picking up the device chip and bonding it to the wiring board, the problem that the cutting chips remaining in the cutting groove 80 fall off and deteriorate the quality of the electronic component is solved.

[0034] (Transfer process) After performing the cutting process, a transfer process is performed to transfer the cut wafer W to the spinner table 42.

[0035] In the transfer process, first, the chuck table 10 is positioned at the above-mentioned handover position (the position shown in FIG. 1) by the X-axis feed means. Next, the suction force of the chuck table 10 is released, and the fixing of the annular frame F by the clamp 14 is released. Then, the cut wafer W is transferred from the chuck table 10 to the spinner table 42 by the second transfer means 78.

[0036] (Cleaning process) After performing the transfer process, a cleaning process is performed to clean the cut wafer W.

[0037] In the cleaning process, first, suction force is generated on the suction chuck 46 of the spinner table 42, and the machined wafer W is sucked and held on the spinner table 42. At this time, the spinner table 42 is positioned at the ascending position shown in FIG. 3, and the second nozzle part 26b and the air nozzle 58 are positioned at the standby positions shown in FIG. 3.

[0038] After the wafer W is sucked and held by the spinner table 42, the wafer W is cleaned by spraying processing water (cleaning water) toward the wafer W. At this time, first, the spinner table 42 is positioned at a predetermined descending position by the elevating means 50. Next, the second nozzle part 26b is rotated to the spraying position, and as shown in FIGS. 2 and 4, the injection port 26b' is positioned above the central part of the wafer W. Then, while rotating the spinner table 42 in the direction indicated by the arrow R2 in FIG. 2 at a predetermined rotational speed (for example, about 300 to 1000 rpm), the bubble-mixed processing water is sprayed from the injection port 26b' of the second nozzle part 26b to clean the wafer W.

[0039] When cleaning the wafer W, the bubble-mixed processing water and air (two fluids) are sprayed from the injection port 26b' of the second nozzle part 26b onto the wafer W held on the spinner table 42. That is, the processing water is supplied from the processing water supply source 28 to the bubble mixing part 24, and the bubble mixing part 24 mixes bubbles into the processing water. The bubble-mixed processing water is pressurized in the pressurizing part 30 by the high-pressure air supplied from the high-pressure air source 32. Then, the second on-off valve 56 is opened, and the bubble-mixed processing water and air are sprayed from the injection port 26b' of the second nozzle part 26b. Therefore, according to the present embodiment, even if the cutting chips in the cutting groove 80 cannot be completely removed during the cutting process, in the cleaning process, the bubble-mixed processing water and air (two fluids) are sprayed again, so that the cutting chips can be surely removed from the cutting groove 80.

[0040] After washing the wafer W, dry air is jetted toward the wafer W to dry the wafer W. At this time, the second nozzle part 26b is rotated to the standby position. Also, the air nozzle 58 is rotated to the jet position, and the jet port 58' is positioned above the center part of the wafer W. Then, while rotating the spinner table 42 in the direction indicated by the arrow R2 in FIG. 2 at a predetermined rotational speed (for example, about 2000 to 3000 rpm), dry air is jetted from the jet port 58' of the air nozzle 58 to dry the wafer W.

[0041] After drying the wafer W, the wafer W is conveyed from the spinner table 42 to the temporary placement table 70 by the first conveying means 74, and then the wafer W is carried into the cassette 66 from the temporary placement table 70 by the carry-in / carry-out means 72.

[0042] As described above, in the cutting device 2 of the illustrated embodiment, when performing cutting and when cleaning the cut wafer W, bubble-containing processing water and air (two fluids) are jetted. For this reason, since the bubbles mixed in the processing water are pushed into the cutting groove 80 by the air, the bubbles capture the cutting chips in the cutting groove 80, and the captured cutting chips float to the upper part of the cutting groove 80 together with the bubbles and are removed from the wafer W by the processing water and air. Therefore, according to the present embodiment, since no cutting chips remain in the cutting groove 80, when picking up the device chip and bonding it to the wiring board, the problem that the cutting chips remaining in the cutting groove 80 fall off and deteriorate the quality of the electronic component is solved.

[0043] Note that the cutting device according to the present invention is not limited to the above-described form, and various modifications are possible. For example, as shown in FIG. 5, the first nozzle portion 26a may include a vertical injection nozzle 82 disposed behind the cutting blade 20. The position of the vertical injection nozzle 82 in the Y-axis direction is aligned with the position of the cutting blade 20 in the Y-axis direction. When performing cutting, not only the pair of injection nozzles 40 but also the bubble-containing machining water and air are injected directly downward from the vertical injection nozzle 82. Then, the bubbles mixed in the machining water are pushed vertically into the cutting groove 80 by the air, so that the cutting chips in the cutting groove 80 can be removed more effectively.

Explanation of Reference Numerals

[0044] 2: Cutting device 4: Holding means 6: Cutting means 8: Machining water supply means 20: Cutting blade 24: Bubble mixing portion 26: Nozzle portion '26a': First nozzle portion '26b': Second nozzle portion 42: Spinner table 44: Cleaning means

Claims

**Claim 1** A cutting device comprising: holding means for holding a workpiece; cutting means rotatably provided with a cutting blade for cutting the workpiece held by the holding means; and a machining water supply means. The machining water supply means includes a bubble mixing section for mixing bubbles into the machining water, and a nozzle section for jetting the machining water with bubbles mixed therein by air. The nozzle section is disposed in a region where the workpiece held by the holding means is cut by the cutting blade. **Claim 2** A cutting device comprising: a spinner table rotatably holding a machined workpiece; and cleaning means for cleaning the workpiece held by the spinner table. The cleaning means is disposed in a region where the nozzle section of the machining water supply means faces the workpiece held by the spinner table. The cutting device according to claim 1. **Claim 3** The cutting device according to claim 1, wherein the diameter of the bubbles mixed into the machining water by the bubble mixing section is less than 1 μm.

Images