JP2011042009A - Cutting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting device for preventing the deposition of cutting debris on a workpiece. <P>SOLUTION: The cutting device with a blade cover includes a liquid wall forming means having a pair of jet nozzles arranged on both sides of a cutting blade upstream in a cutting blade rotating direction, namely, in the direction of rotating the cutting blade at its lowest point, while holding therebetween the front end of the cutting blade protruded from an opening formed on the bottom of the blade cover, for jetting liquid wall forming liquid from the jet nozzles along the cutting blade rotating direction downstream in the cutting blade rotating direction to form a pair of liquid walls extending longer than the opening in the cutting blade rotating direction to seal a clearance between the blade cover and the workpiece. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cutting apparatus that includes a chuck table that holds a workpiece, a cutting blade that cuts the workpiece held on the chuck table, and a blade cover that is disposed so as to cover the outer periphery of the cutting blade. About.

  In a semiconductor device manufacturing process, a plurality of devices such as ICs, LSIs, solid-state image sensors, etc. are formed on the surface of a semiconductor wafer. Then, the wafer is divided into individual devices by cutting the wafer along a planned division line called a street dividing each device with a cutting device.

  A cutting device called a dicer is widely used as a cutting device, and the dicer includes a cutting means including a cutting blade. The cutting blade has a cutting blade having a thickness of about several tens to several hundreds of microns by hardening superabrasive grains such as diamond and CBN (Cubic Boron Nitride) with metal or resin, and the cutting blade is about 30000 rpm. The workpiece is divided by cutting into the workpiece while rotating at a high speed, and cutting and removing a part of the workpiece.

  In order to cool the processing heat generated by cutting and to discharge the cutting waste generated by cutting from the workpiece, the dicer has a processing point (a point where the cutting blade and the workpiece contact) and the upper surface of the workpiece. Cutting is performed while supplying cutting water.

  In particular, when the workpiece is a wafer having an imaging device such as a CCD or CMOS formed on the surface, or a substrate on which an optical device such as an optical filter or an optical pickup device is formed on the surface, the cutting waste is formed on the device. Since adhesion causes a device failure, it is very important to prevent adhesion of cutting waste.

  Since the cutting waste once adhered and dried on the workpiece is very difficult to remove in the subsequent cleaning step, the cutting waste generated during cutting as disclosed in JP-A-2006-289509 is disclosed. And a method of preventing cutting chips from adhering to the workpiece during cutting using a mechanism for removing the cutting water together with cutting water and a processing agent as disclosed in JP-A-2006-150844. ing.

JP 2006-289509 A JP 2006-150844 A

  However, even with the apparatus or method disclosed in Patent Documents 1 and 2, there is a problem that it is difficult to completely prevent the cutting waste from adhering to the workpiece.

  This invention is made | formed in view of such a point, The place made into the objective is providing the cutting device which can prevent adhesion to the cutting waste on a workpiece.

  According to the present invention, a chuck table for holding a workpiece, a cutting blade for cutting the workpiece held on the chuck table, an opening from which the tip of the cutting blade projects at the bottom, and a workpiece A cutting device including a blade cover that forms a gap between a workpiece and the bottom during cutting, and the rotation direction of the cutting blade at the lowest point of the cutting blade is the cutting blade rotation direction A pair of jets disposed on both sides of the cutting blade on the upstream side in the cutting blade rotation direction so as to sandwich the tip of the cutting blade protruding from the opening. A liquid wall forming liquid that forms a liquid wall is ejected along the blade rotation direction toward the downstream side of the cutting blade rotation direction, and extends in the cutting blade rotation direction longer than the opening. A liquid wall forming unit that forms a pair of liquid walls and seals the gap; a cutting fluid supply unit that is disposed between the pair of ejection ports and supplies the cutting fluid to the cutting blade; and the cutting The cutting fluid supplied to the blade and rotated with the rotation of the cutting blade and the liquid wall forming liquid forming the liquid wall are disposed on the side where the liquid is scattered, and the cutting fluid and the liquid wall forming liquid are processed. There is provided a cutting device comprising a discharge means for discharging from an object.

  Preferably, the cutting device further includes a pair of guide walls that are formed on both sides of the cutting blade so as to sandwich the cutting blade and guide the liquid wall forming liquid in the cutting blade rotation direction.

  Preferably, the discharge means includes suction means.

  According to the present invention, the cutting blade is almost entirely covered with the blade cover, and the cutting fluid mixed with the cutting waste is guided to the downstream side in the rotation direction of the cutting blade by the liquid wall, so that the cutting fluid and the liquid wall are formed. Since the liquid is discharged from the workpiece through the discharging means, it is possible to prevent the cutting waste from adhering to the workpiece.

  According to the second aspect of the invention, the liquid wall forming liquid flows out only in the rotating direction of the cutting blade by the guide wall, and the guide wall can prevent the liquid wall forming liquid from colliding with the cutting blade and scattering.

  According to the third aspect of the present invention, the cutting fluid and the liquid wall forming fluid mixed with the cutting waste can be more effectively discharged by forcibly suctioning with the suction means.

It is an external appearance perspective view of a cutting device. It is a disassembled perspective view which shows a mode that a cutting blade is attached to a spindle. It is a perspective view in the state where a cutting blade was attached to a spindle. It is a perspective view of the blade cover of a 1st embodiment. It is a longitudinal cross-sectional view of the blade cover of 1st Embodiment at the time of wafer cutting. It is a bottom view of the blade cover of a 1st embodiment. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 6. 8A is a sectional view taken along line 8A-8A in FIG. 6, and FIG. 8B is a sectional view taken along line 8B-8B in FIG. It is a perspective view of the blade cover of 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the appearance of the cutting device 2 according to the first embodiment of the present invention. On the front side of the cutting device 2, there is provided operating means 4 for an operator to input instructions to the device such as machining conditions. In the upper part of the apparatus, there is provided a display means 6 such as a CRT for displaying a guidance screen for an operator and an image taken by an imaging means described later.

  Reference numeral 8 denotes a wafer cassette, and a plurality of semiconductor wafers (for example, 25 wafers) supported by an annular frame via a dicing tape are accommodated in the wafer cassette 8. The wafer cassette 8 is placed on a cassette elevator 9 that can move up and down.

  Behind the wafer cassette 8, a loading / unloading means 10 for unloading the wafer W before cutting from the wafer cassette 8 and loading the wafer after cutting into the wafer cassette 8 is disposed. Between the wafer cassette 8 and the loading / unloading means 10, a temporary placement area 12, which is an area on which a wafer to be carried in / out, is temporarily placed, is provided. Positioning means 14 for positioning at a certain position is provided.

  In the vicinity of the temporary placement area 12, transport means 16 having a turning arm that sucks and transports the frame F integrated with the wafer W is disposed, and the wafer W carried to the temporary placement area 12 is Adsorbed by the conveying means 16 and conveyed onto the chuck table 18 and sucked by the chuck table 18, and held on the chuck table 18 by fixing the frame F by a plurality of fixing means (clamps) 19. .

  The chuck table 18 is configured to be rotatable and reciprocally movable in the X-axis direction. Above the movement path of the chuck table 18 in the X-axis direction, an alignment unit 20 that detects a street to be cut of the wafer W is provided. It is arranged.

  The alignment unit 20 includes an imaging unit 22 that images the surface of the wafer W, and can detect a street to be cut by a process such as pattern matching based on an image acquired by imaging. The image acquired by the imaging unit 22 is displayed on the display unit 6. The imaging means 22 includes an infrared camera in addition to a normal camera that captures an image with visible light.

  On the left side of the alignment means 20, a cutting means 24 for cutting the wafer W held on the chuck table 18 is disposed. The cutting means 24 is configured integrally with the alignment means 20, and both move together in the Y-axis direction and the Z-axis direction.

  As shown in FIG. 3, the cutting means 24 is configured by attaching a cutting blade 28 to the tip of a rotatable spindle 26, and is movable in the Y-axis direction and the Z-axis direction. The cutting blade 28 is located on the extended line of the imaging means 22 in the X-axis direction.

  In the present embodiment, the cutting blade 28 is almost entirely covered with a blade cover 58. Reference numeral 56 denotes pool liquid supply means for filling a space between the upper surface of the workpiece and the bottom of the blade cover 58 during the cutting of the workpiece such as a wafer, and is installed outside the blade cover 58 in this embodiment. Yes. The pool liquid supply means 56 can be installed at an arbitrary place where the pool liquid can be supplied onto the workpiece, for example, installed on the blade cover 58.

  Reference numeral 25 denotes transport means for transporting the wafer W after cutting to the cleaning device 27. The cleaning device 27 cleans the wafer W and blows air from the air nozzle to dry the wafer W.

  Referring to FIG. 2, there is shown an exploded perspective view showing the mounting relationship between the spindle 26 having the blade mount 36 fixed to the tip thereof and the cutting blade 28. A spindle 26 is rotatably accommodated in a spindle housing 32 of a cutting means (cutting unit) 24.

  The blade mount 36 includes a boss portion 38 and a fixed flange 40 formed integrally with the boss portion 38. A male screw 42 is formed on the boss portion 38. The blade mount 36 is formed by inserting a mounting hole of the blade mount 36 into a small diameter portion and a tapered portion (not shown) of the spindle 26 and screwing a nut 44 into a male screw formed on the small diameter portion of the spindle 26 and tightening. , Attached to the tip of the spindle 26.

  By inserting the mounting hole 52 of the cutting blade 28 into the boss portion 38 of the blade mount 36 and screwing the fixing nut 54 into the male screw 42 of the boss portion 38 and tightening, the cutting blade 28 is moved to the spindle 26 as shown in FIG. Attached to.

  The cutting blade 28 is called a hub blade, and is an electroformed blade having a cutting edge 50 in which diamond abrasive grains are fixed by nickel plating on the outer periphery of a circular base 46 having a circular hub 48. The cutting blade 50 of the cutting blade 28 has a thickness of 20 to 30 μm.

  Referring to FIG. 4, a perspective view of the blade cover 58 according to the first embodiment of the present invention is shown. The blade cover 58 includes a first cover 60 and a second cover 62 that is detachably fixed to the first cover 60 with, for example, a fastening screw.

  The blade cover 58 includes a ceiling part 58a, a bottom part 58b facing the ceiling part 58a having an opening 64 from which the tip of the cutting blade 28 protrudes, and a side wall part 58c connecting the ceiling part 58a and the bottom part 58b.

  A space 66 is defined in the blade cover 58, and the cutting blade 28 is inserted into the space 66, and the cutting blade except for the tip of the cutting blade 28 that acts as a processing point protruding from the opening 64. 28 is covered with a blade cover 58. Reference numeral 65 denotes a cutting fluid discharge opening communicating with the space 66, and 67 denotes a spindle insertion opening into which the spindle 26 is inserted.

  The blade cover 58 has a cutting fluid supply path 68, one end of the cutting fluid supply path 68 is connected to a cutting fluid supply source 70, and the other end is supplied with cutting fluid into a space 66 in which the cutting blade 28 is inserted. A jet outlet 72 for jetting is formed. The cutting fluid supply path 68, the cutting fluid supply source 70, and the cutting fluid outlet 72 constitute a cutting fluid supply means.

  Reference numeral 74 denotes a liquid wall forming liquid supply path, one end of which is connected to the liquid wall forming liquid supply source 76 and the other end of the pair of branches extending to both the front and back surfaces of the cutting blade 28 inserted into the space 66. It is connected to supply paths 74a and 74b. Each branch supply path 74 a, 74 b is connected to a jet outlet 78.

  As best shown in FIG. 5, the bottom 58 b of the blade cover 58 is formed on both sides of the cutting blade 28 so as to sandwich the cutting blade 28, and a pair for guiding the liquid wall forming liquid along the cutting blade 28. The guide wall 80 is formed.

  Therefore, the liquid wall forming liquid ejected from the ejection ports 78 of the branch supply paths 74 a and 74 b forms a pair of liquid walls 82 along the cutting blade 28 longer than the opening 64 of the blade cover 58, and these liquid walls 82. Thus, the gap between the bottom 58b of the blade cover 58 and the wafer W is sealed.

  Reference numeral 88 denotes discharge means, which includes a cylindrical body 90 extending in the vertical direction and a suction source 92. An opening 90a is formed at the lower end of the cylindrical body 90. When the suction source 92 is operated, cutting fluid mixed with cutting waste is sucked into the cylindrical body 90 through the cutting fluid discharge opening 65 and liquid wall forming liquid. Is sucked into the cylindrical body 90 through the opening 90a and discharged from the wafer W. The discharge means 88 shown in FIG. 4 has a cylindrical body 90 formed in the vertical direction, but the cylindrical body 90 may be inclined from the vertical direction.

  Next, the operation of the above-described first embodiment of the present invention will be described. The wafer W, which is a workpiece, is sucked and held on the chuck table 18 while being supported by the annular frame F via the dicing tape T as shown in FIG.

  Alignment is performed in which the wafer W held by the chuck table 18 is moved in the X-axis direction and moved immediately below the image pickup means 22, the wafer W is picked up by the image pickup means 2, and the street to be cut is detected by the alignment means 20. carry out.

  Based on this alignment, the street to be cut and the cutting blade 28 are aligned, and the cutting blade 28 inserted into the space 66 in FIG. 4 is moved at a high speed of about 30000 rpm in the direction of arrow A. By cutting into the wafer W while rotating, and further feeding the chuck table 18 in the direction of arrow B, the aligned street is cut.

  When the street is cut by the cutting blade 28, the cutting fluid is ejected from the cutting fluid ejection port 72 toward the cutting edge 50 of the cutting blade 28, and the liquid wall forming fluid is ejected from the ejection port 78 to remove the cutting blade 28. While forming a pair of liquid walls 82 on both sides, the street of the wafer W is cut.

  At the same time, the pool liquid 86 is supplied from the pool liquid supply means 56, and the space between the wafer W held on the chuck table 18 and the bottom 58 b of the blade cover 58 is filled with the pool liquid 86. As the cutting fluid, the liquid wall forming fluid, and the pool fluid 86, pure water is generally used.

  A part of the cutting waste generated by the cutting rotates with the cutting fluid as the cutting blade 28 rotates, and the cutting fluid containing the cutting waste passes through a cutting fluid discharge opening 65 formed in the side wall 58c of the blade cover 58. It is taken into the cylinder 90 of the discharge means 88 and is removed by suction by the operation of the suction source 92.

  Further, the liquid wall forming liquid which is ejected from the ejection port 78 and guided by the guide wall 80 to form the liquid wall 82 extending on both sides of the cutting blade 28 is operated through the opening 90 a by operating the suction source 92. Then, it is taken into the cylinder 90 and removed by suction.

  According to the present embodiment, the cutting fluid mixed with the cutting waste is prevented from diffusing in the axial direction of the spindle 26 by the liquid walls 82 formed on both sides of the cutting blade 28, and through the opening 90 a of the cylindrical body 90. Since it is taken into the cylinder 90 and removed by suction by the action of the suction source 92, it is possible to prevent the cutting waste from adhering to the wafer W.

  The liquid wall forming liquid forming the liquid wall 82 flows out only to the discharge means 88 side by the guide wall 80, and the guide wall 80 can prevent the liquid wall 82 from colliding with the cutting blade 28 and scattering.

  Further, as shown in FIG. 5, during the cutting process, the pool liquid 86 is supplied from the pool liquid supply means 56 to the upper surface of the wafer W, whereby the pool liquid 86 is provided between the upper surface of the wafer W and the bottom 58b of the blade cover 58. It is prevented that the cutting waste that fills and remains on the wafer W without being mixed into the cutting fluid is fixed on the wafer W.

  Furthermore, since the flow velocity at which the liquid wall forming liquid is ejected is faster than the pool liquid 86, a part of the pool liquid 86 is caught in the liquid wall 82 by the Bernoulli effect. As a result, the cutting waste that has not been mixed in the cutting fluid and has floated in the pool liquid can be taken into the liquid wall forming liquid and discharged from the wafer W.

  Each water amount and suction so that the suction amount of the suction source 92 is “the amount of cutting fluid supplied” + “the amount of liquid wall forming fluid supplied” + “the amount of pool liquid flowing into the liquid wall” <“suction amount” Adjust the amount. If the suction amount by the suction source 92 is insufficient, the cutting waste cannot be sufficiently removed by suction. Conversely, if the suction amount is excessive, the upper surface of the wafer W is locally dried. Will adhere to the upper surface of the wafer W, it is preferable to adjust the relationship between the amount of water and the amount of suction as appropriate.

  Referring to FIG. 9, a perspective view of a blade cover 58A according to a second embodiment of the present invention is shown. The configuration of the blade cover 58A of the present embodiment is substantially the same as that of the blade cover 58 of the first embodiment described above, but the configuration of the discharge means 88A connected to the blade cover 58A is different from that of the first embodiment. The discharge means 88 </ b> A of the present embodiment is configured by a discharge path cover 94 disposed horizontally on the side where the cutting fluid supplied to the cutting blade 28 scatters as the cutting blade 28 rotates.

  In the present embodiment, the cutting fluid mixed with cutting waste is taken into the discharge path cover 94 through the cutting fluid discharge opening 65 formed in the side wall 58c of the blade cover 58A, and is discharged as shown by an arrow C. Further, since the liquid wall forming liquid forming the liquid wall 82 is also taken into the discharge path cover 94 and discharged as indicated by the arrow C, the cutting waste is prevented from adhering to the wafer W.

  In the present embodiment, since the discharge means 88A is configured by the discharge path cover 94 disposed on the side where the cutting fluid scatters without providing the suction source 92 of the first embodiment, the configuration of the discharge means is simplified. be able to.

18 Chuck table 24 Cutting means (cutting unit)
28 Cutting blade 56 Pool liquid supply means 58, 58A Blade cover 68 Cutting liquid supply path 74 Liquid wall forming liquid supply path 80 Guide wall 82 Liquid wall

Claims (4)

A chuck table for holding a workpiece, a cutting blade for cutting the workpiece held on the chuck table, and an opening from which a tip of the cutting blade protrudes at the bottom, and the workpiece when cutting the workpiece And a cutting device provided with a blade cover in which a gap is formed between the bottom and
When the rotation direction of the cutting blade at the lowest point of the cutting blade is the cutting blade rotation direction, the cutting blade is disposed upstream of the cutting blade rotation direction so as to sandwich the tip of the cutting blade protruding from the opening. A pair of jet nozzles disposed on both sides are provided, and a liquid wall forming liquid is ejected from the jet nozzle along the rotation direction of the cutting blade toward the downstream side of the cutting blade rotation direction. A liquid wall forming means for forming a pair of liquid walls extending in the rotation direction of the cutting blade longer than the opening and sealing the gap;
A cutting fluid supply means disposed between the pair of jet nozzles to supply the cutting fluid to the cutting blade;
The cutting fluid supplied to the cutting blade and rotated along with the rotation of the cutting blade and the liquid wall forming liquid forming the liquid wall are disposed on the side where the liquid is formed. Discharging means for discharging from the workpiece;
A cutting apparatus comprising:   The cutting apparatus according to claim 1, further comprising a pair of guide walls formed on both sides of the cutting blade so as to sandwich the cutting blade and guiding the liquid wall forming liquid in the rotation direction of the cutting blade.   The cutting apparatus according to claim 1 or 2, wherein the discharging means includes suction means.   The cutting device according to any one of claims 1 to 3, wherein the cutting fluid and the liquid wall forming fluid are composed of pure water.

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