JP2009111038A - Cleaning device of chuck table - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To uniformly clean the chucking face of a chuck table, and prevent the generation of ring-like remaining abrasion or deflected abrasion, as well as the abrasive damage of the chucking face by an edge of a cleaner stone. <P>SOLUTION: A stone pressing mechanism 600 elastically supports the table turning-direction upstream-side ends 511 and 521 of stone holders 510 and 520 by cantilever plate springs 621 and 622 extended to the turning-direction upstream side so that they may be elastically close or away to/from the chucking face 210. A cleaner stone 400 is comprised of a plurality of divided stones 410 and 420, and the divided stones 410 and 420 are arranged in a vertical row along the radial direction of the chucking face when they land on the chucking face 210. Furthermore, the ends 411 and 421 of the divided stones 410 and 420 which are adjacent to each other are overlaid in the table turning direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an apparatus for cleaning a chuck surface of a chuck table provided in a wafer processing apparatus such as a silicon wafer grinding apparatus.

  In a silicon wafer manufacturing process, a silicon wafer cut out from a silicon rod (ingot) into a disk shape is subjected to a grinding process for roughing the silicon wafer as a pre-process for a polishing process for mirror finishing. In this grinding step, the silicon wafer is ground and adjusted so as to have a desired thickness and flatness using a grinding apparatus.

  The grinding device is provided with a rotatable disk-shaped chuck table. A silicon wafer is chucked on the chuck surface by vacuum suction, and the surface opposite to the suction surface of the silicon wafer is ground by a diamond grindstone or the like.

  In the grinding process, every time a silicon wafer is ground, fine grinding debris and grinding wheel wear powder are generated, and these grinding debris and wear powder adhere to the chuck surface of the chuck table. When the next silicon wafer is adsorbed while foreign matter such as grinding dust or wear powder remains on the chuck surface of the chuck table, the ground surface of the silicon wafer partially protrudes due to the presence of the foreign matter. Therefore, if the silicon wafer is ground in this state, a grinding dent is generated at a portion corresponding to the portion where the foreign matter of the silicon wafer is interposed, and a desired flatness cannot be obtained.

  Therefore, conventionally, the grinding apparatus is provided with a cleaning device as disclosed in Patent Document 1, and each time a grinding process of each silicon wafer is completed, the chuck surface of the chuck table is cleaned by the cleaning device. Has been removed.

  This cleaning device rotates a chuck table to bring a stick-shaped cleaner stone into contact with a radial portion of the chuck surface and oscillates the cleaner stone along the radial direction of the chuck surface. Is a device for cleaning. The cleaner stone is an elongated rod-shaped member made of ceramic, and the contact portion is subjected to curvature processing (R processing) in order to reduce contact resistance, and is in line contact with the chuck surface. .

  In recent years, large-diameter silicon wafers of 300 mmφ have become mainstream, but as shown in FIG. 1, two cleaner stones 21 and 22 are arranged in a straight line in a radial position on the chuck surface 11 of the chuck table 10. Thus, the chuck surface 11 is cleaned. This is because it is difficult to produce long cleaner stones 21 and 22 exceeding about 80 mm due to restrictions on the apparatus for curvature processing of the contact portions of the cleaner stones 21 and 22.

  Further, as shown in FIG. 2, the wear amount of the chuck surface 11 of the chuck table 10 increases as the distance from the center portion increases, and the center portion of the chuck surface 11 protrudes upward by about 5 to 10 μm with respect to the peripheral portion. . That is, when expressed in an extreme manner, the side surface of the chuck table 10 is formed to have a substantially conical shape, and may have irregularities of about several μm even within a radius range from the fabrication of the wafer. Therefore, it is easier to follow the shape of the chuck surface 11 if the two cleaner stones 21 and 22 are arranged separately on the chuck surface 11 of the chuck table 10.

  As shown in FIG. 3, the cleaner stones 21 and 22 are held on the lower surfaces of rectangular plate-shaped stone holders 31 and 32. Through holes 33 are formed at the four corners of the stone holders 31 and 32, and through bolts 41 suspended from a pressing mechanism (not shown) are inserted into the through holes 33, respectively. The coil springs 42 are interposed around the bolts 41 so that the stone holders 31 and 32 are elastically supported by the pressing mechanism and receive a frictional force in the rotation direction of the chuck table 10.

  The cleaning device 1 is operated by rotating the chuck table 10 at the same time as the cleaner stones 21 and 22 move toward the chuck surface 11, and at the same time the cleaner stones 21 and 22 are retracted from the chuck surface 11. The rotation of 10 is stopped.

JP 2007-184212 A

  By the way, in the conventional cleaning apparatus 1, since the two cleaner stones 21 and 22 are arranged in a straight line, a gap of about 0.5 mm or more (substantially 1 mm) is provided between the cleaner stones 21 and 22 during assembly. Is set. When the cleaner stones 21 and 22 are brought into contact with the chuck surface 11 of the rotating chuck table 10, both the cleaner stones 21 and 22 and the chuck surface 11 are worn, but the clearance between these cleaner stones 21 and 22 is the chuck surface. 11 does not contact, and the wear of the chuck surface 11 does not occur. As described above, the cleaner stones 21 and 22 are oscillated along the radial direction of the chuck surface 11, but when the oscillating amount is as small as about 5 mm, the intermediate portion of the chuck surface 11 is caused by the gap. A ring-shaped convex wear residue is formed.

  Further, the cleaner stones 21 and 22 tend to be inclined toward the upstream side in the rotation direction due to the frictional force generated by the rotation of the chuck table 10. At this time, the force in the rotation direction of the chuck table 10 causes the inner peripheral surface of the through hole 33 of the stone holder 31 (32) and the outer peripheral portion of the bolt 41 to rub, as shown in FIG. If foreign matter such as grinding scraps adheres to the surface, it will bend and restrain the movement of the cleaner stones 21 and 22 in the vertical direction, making it impossible to apply uniform pressure to the chuck surface 11 and uneven wear of the chuck surface 11 will occur. appear.

  Further, the cleaner stones 21 and 22 are oscillated along the radial direction of the chuck surface 11 of the chuck table 10. As shown in FIG. 5, the swing stroke ST of the cleaner stones 21 and 22 is Δr (porous ceramic). If the distance between the outer peripheral portion of the portion 13 and the extended end portion of the cleaner stone 22 is larger than the edge portion 23 of the outer cleaner stone 22, the edge portion 23 enters the chuck surface 11. Wear damage occurs.

  In the operation of the cleaning apparatus 1, the cleaner stones 21 and 22 are seated on the chuck surface 11 while the chuck table 10 is rotated, and the chuck table 10 is rotated after the cleaner stones 21 and 22 are retracted. Is stopped. However, it is very difficult to control the posture of the cleaner stones 21 and 22 to be parallel to the chuck surface 11 of the chuck table 10, and the edge portions 23 of the cleaner stones 21 and 22 are lowered as shown in FIG. Prone to stick out. Therefore, when the cleaner stones 21 and 22 are landed (withdrawn) while the chuck table 10 is rotating, wear damage to the chuck surface 11 occurs due to the protruding edge portion 23 of the cleaner stones 21 and 22.

  Accordingly, an object of the present invention is to provide a chuck table cleaning device that more uniformly cleans the chuck surface of the chuck table.

  A chuck table cleaning apparatus according to the present invention includes a rotatable chuck table for adsorbing a wafer, a cleaner stone, and a stone pressing mechanism for elastically supporting the cleaner stone and landing the cleaner stone on the chuck surface of the chuck table. The stone pressing mechanism includes a stone holder on which the cleaner stone is mounted, and the upstream end portion of the stone holder in the table rotating direction is supported by a cantilevered leaf spring extending upstream in the rotating direction. The elastic support is provided so as to be elastically close to and away from the chuck surface.

  According to the above configuration, when a force in the table rotation direction due to the rotation of the chuck table is applied to the cleaner stone, the force acts in a direction in which the leaf spring is extended, so that the leaf spring can counter the force and the cleaner stone is The elastic support is continued so as to elastically approach and separate from the chuck surface. Further, the force in the chuck surface radial direction due to the oscillating operation of the cleaner stone acts in the bending direction of the leaf spring, but if the strength is given by the width dimension of the leaf spring, this repulsive force can be countered.

  In a preferred embodiment, the downstream end of the stone holder in the table rotation direction is elastically supported so as to elastically approach and separate from the chuck surface. For example, the downstream side of the stone holder in the table rotation direction is elastically supported by a coil spring or other elastic member that urges the stone holder toward the chuck table and a restriction member that restricts the movement of the stone holder toward the chuck table.

  In a preferred embodiment, the cleaner stone is composed of a plurality of divided stones, and these divided stones are arranged in tandem with the stone pressing mechanism so as to be along the radial direction of the chuck surface when landing on the chuck surface, The adjacent ends of the divided stones are arranged so as to overlap in the table rotation direction.

  According to the above-described configuration, the plurality of divided stones are arranged in tandem, and the adjacent ends of the divided stones are arranged so as to overlap in the table rotation direction. No gap is formed. Accordingly, the line contact portions of the divided stones come into contact with each other in the chuck surface radial direction, and uniform cleaning can be performed on the entire chuck surface of the chuck table.

  Further, the total length of the cleaner stone composed of the plurality of divided stones is set to be equal to or larger than the radius of the chuck table, and the extending end of the cleaner stone protrudes radially outward from the outer peripheral portion of the chuck table. And is set so as to protrude radially outward from the outer peripheral portion of the chuck surface on the chuck table, and the stone pressing mechanism causes the cleaner stone to protrude to the center side of the chuck surface and swing. It is preferable that an oscillating means is provided, and the swing stroke of the cleaner stone is set smaller than the distance between the radius of the chuck table and the radius of the wafer. As a result, the cleaner stone always comes into contact with the chuck surface of the chuck table (that is, the region that sucks the workpiece (wafer)) within the oscillating stroke range.

  Further, it is preferable that the stone pressing mechanism causes the cleaner stone to land on the chuck surface before the chuck table starts rotating, and retracts the cleaner stone from the chuck surface after the chuck table stops rotating.

  According to the chuck table cleaning apparatus of the present invention, since the cleaner stone can be continuously elastically supported, more uniform cleaning can be performed on the entire chuck surface of the chuck table. Further, according to a preferred embodiment of the present invention, it is possible to reduce the problem of occurrence of ring-like wear residue and uneven wear on the chuck surface of the chuck table, and wear of the chuck surface by the edge portion of the cleaner stone. Damage can be reduced.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 7 is a bottom view of an embodiment of the chuck table cleaning device according to the present invention. 8A is a cross-sectional view taken along the line AA in FIG. 7, and FIG. 8B is a cross-sectional view taken along the line BB in FIG. FIGS. 8A and 8B are shown rotated 90 degrees counterclockwise for easy viewing. FIG. 9 is a rear view of the chuck table cleaning device of the present embodiment, and corresponds to the X view of FIG. FIG. 10 is a schematic view of a state in which a cleaner stone is landed on the chuck surface of the chuck table. In FIG. 9, a later-described regulating member is omitted, and SL is the center of the chuck table 200.

  As shown in FIGS. 7 to 10, the chuck table cleaning apparatus 300 according to the present embodiment is configured to perform vacuum cutting by vacuum-sucking a silicon wafer onto the chuck surface 210 of the chuck table 200 and roughing the surface opposite to the suction surface. The device 100 is provided. That is, as shown in FIG. 7 to FIG. 9, the chuck table cleaning apparatus 300 includes a cleaner stone 400 held by the stone holder 500 and a cleaner stone 400 on the chuck surface 210 of the chuck table 200 by elastically supporting the stone holder 500. And a stone pressing mechanism 600 that presses the cleaner table 400, and cleaning is performed by bringing the cleaner stone 400 into contact with the chuck surface 210 while rotating the chuck table 200.

  As shown in FIG. 10, the chuck table 200 is a circular turntable and is supported by a rotating shaft 220. The rotating shaft 220 is driven to rotate by, for example, a belt drive or a direct drive. The outer shell 230 of the chuck table 200 has an edged dish shape and is formed of dense ceramics. A porous ceramic portion 240 is formed in the outer shell portion 230 by sintering molding, thermal spraying, or the like, and these dense ceramics are combined.

  A plurality of through holes 250 are formed in the bottom surface of the outer shell portion 230, and these through holes 250 communicate with an exhaust system 270 of an exhaust means 260 such as a vacuum pump. Since the porous ceramic portion 240 of the chuck table 200 has a large number of air holes, the inside of the outer shell portion 230 is evacuated through the through-hole 250, so that the surface (chuck surface) 210 of the porous ceramic portion 240 is siliconized. The wafer can be sucked.

  FIG. 11 is a plan view and a side view of the cleaner stone in the present embodiment. FIG. 12 is a plan view and a side view of a conventional cleaner stone.

  As shown in FIG. 11, the cleaner stone 400 includes a plurality of divided stones 410 and 420, and in the present embodiment, the cleaner stone 400 includes two divided stones 410 and 420. In the present embodiment, this is applied to cleaning the chuck surface 210 of the chuck table 200 that adsorbs a 300 mmφ silicon wafer, and each of the divided stones 410 and 420 is set to a length of 80 mm or less, for example. These divided stones 410 and 420 are arranged in tandem in the stone pressing mechanism 600 so that the longitudinal direction thereof is along the radial direction of the chuck surface when it lands on the chuck surface 210 of the chuck table 200.

  In the present embodiment, these divided stones 410 and 420 are arranged in tandem on a straight line, and the adjacent ends of the divided stones 410 and 420 are formed so as to be inclined, so that these adjacent ends are the table. It arrange | positions so that it may overlap in a rotation direction. The inclination angle θ of the adjacent ends of the divided stones 410 and 420 is preferably set to 30 degrees with respect to the longitudinal side surfaces of the divided stones 410 and 420.

  The divided stones 410 and 420 are inclined and cut at both ends in the longitudinal direction of the divided stones 410 and 420 in order to provide component compatibility between them. Further, the lower surfaces of the divided stones 410 and 420 (surfaces facing the chuck surface) have line contact portions 413 and 423 to the chuck surface in regions on the surfaces where the inclined cut is not performed in the width direction. It is chamfered so as to be positioned so as to be biased to one side in the width direction. Therefore, the line contact portions 413 and 423 of the divided stones 410 and 420 arranged in a column are alternately arranged.

  For example, when the inclination angle θ of the inclined cut surfaces at adjacent ends of the divided stones 410 and 420 is set to 30 degrees and the interval between the inclined cut surfaces is set to 0.5 mm, the divided stones 410 and 420 The line contact portions 413 and 423 of 420 are overlapped in the range of 0.46 mm in the radial direction of the chuck surface, and are overlapped on the chuck surface.

  As shown in FIG. 12, in the conventional cleaner stone 20, the divided stones 21 and 22 are arranged to face each other with a spacing of 0.5 mm in the radial direction of the chuck surface 210. When the oscillating operation was performed along the radial direction of 210, the non-contact range became 2.5 mm, and the ring-shaped wear residue as described above was generated.

  On the other hand, in the cleaner stone 400 of the present embodiment, the line contact portions 413 and 423 of the divided stones 410 and 420 overlap with each other within a range of 0.46 mm in the radial direction of the chuck surface. The gap between the divided stones 410 and 420 is not formed. Therefore, uniform cleaning can be performed on the entire chuck surface of the chuck table, and local unevenness of the seam is not generated on the silicon wafer used in the grinding process.

  FIG. 13 is a schematic view illustrating a modification of the cleaner stone in the present embodiment.

  As shown in FIG. 13A, both end portions of each of the divided stones 410 and 420 are cut out in a key shape, and the adjacent key-shaped end portions 411 and 421 of the divided stones 410 and 420 in the table rotation direction. These divided stones 410 and 420 may be arranged in a column by overlapping. Further, as shown in FIG. 13B, the adjacent ends 411 and 421 of the divided stones 410 and 420 are simply overlapped with each other in the table rotation direction, and the divided stones 410 and 420 are obliquely arranged in tandem. May be.

  Again referring to FIG. 7 to FIG. 9, the divided stones 410 and 420 are respectively held on the lower surfaces of the rectangular flat plate shaped stone holders 510 and 520. Specifically, two rows of holding portions 531 and 532 project from the lower surfaces of the two stone holders 510 and 520, and each divided stone 410 is placed in a mounting groove portion 540 formed between the holding portions 531 and 532. 420 are attached. Each holding portion 531 is formed with a female screw portion 551 penetrating along the thickness direction of the holding portion 531, and the divided screws 410 and 420 are formed by screwing the male screw 552 into the female screw portion 551. It is fixed.

  The stone holders 510 and 520 are elastically supported by the stone pressing mechanism 600 as described above. That is, the stone pressing mechanism 600 elastically approaches the chuck surface 210 with the cantilever leaf spring 620 extending upstream of the table holders 520 and 520 in the table rotation direction upstream. While being elastically supported so as to be separated from each other, the downstream end portion in the table rotation direction is elastically supported by a coil spring 630 (or another elastic member) so as to be elastically close to and separated from the chuck surface 210. In the following description, the upstream side in the table rotation direction and the downstream side in the table rotation direction may be simply referred to as the upstream side and the downstream side.

  Specifically, the main body 610 of the stone pressing mechanism 600 is a rectangular flat plate member, and two stone holders 510 and 520 are suspended from the main body 610.

  Fastening pins 560 are fixed to both ends in the longitudinal direction on the upper surfaces of the upstream end portions 511 and 521 of the stone holders 510 and 520, respectively. Each pin 560 is provided with a base end portion of a leaf spring 620 extending to the upstream side in the table rotation direction. The extended end portion of each leaf spring 620 is supported and fixed to a lower portion of a columnar support member 640 that is suspended and fixed to the lower surface of the main body 610 of the stone pressing mechanism 600. A pair of support members 640 is provided for each of the stone holders 510 and 520, and a total of four support members 640 are suspended and fixed to portions corresponding to the extended end portions of the plate springs 620. The leaf spring 620 is formed of, for example, a stainless steel plate material.

  As shown in FIGS. 8A and 8B, for the purpose of equalizing the pressing force to the chuck surface of the divided stones 410 and 420 respectively positioned on the outer peripheral side and the inner peripheral side of the chuck surface, The length (that is, the substantial length of the leaf spring 620) A of the plate spring 620 attached to the holder 510 and the substantial length of the leaf spring 620 attached to the stone holder 520 on the inner periphery side. Is set equal to D. For this purpose, a distance B from the upstream end of the above-mentioned working portion of the leaf spring 620 attached to the stone holder 510 on the outer peripheral side to a position where it contacts the chuck surface of the divided stone 410 on the outer peripheral side, The distance E from the upstream end of the above-mentioned action portion of the leaf spring 620 attached to the circumferential stone holder 520 to the location where it contacts the chuck surface of the inner divided stone 420 is also set equal. Further, for the same purpose, a distance C from the upstream end of the above-mentioned working portion of the leaf spring 620 attached to the outer stone holder 510 to a coil spring 630 (described later) attached to the stone holder 510 on the outer periphery. And the distance F from the upstream end of the working portion of the leaf spring 620 mounted on the inner stone holder 520 to the coil spring 630 described later mounted on the inner stone holder 520 is also set equal. Has been.

  Support pins 570 are fixed to both ends in the longitudinal direction on the upper surfaces of the downstream end portions 512 and 522 of the stone holders 510 and 520, respectively. Further, stepped pins 650 protrude from the lower surface of the stone pressing mechanism 600 on the downstream side of the main body 610 so as to face the support pins 570. The coil spring 630 is mounted around the front ends of the support pin 570 and the stepped pin 650 that face each other.

  Further, two restriction members (stoppers) 660 for restricting the movement of the stone holders 510 and 520 toward the chuck surface on the downstream side in the table rotation direction are suspended from the downstream end face of the main body 610 of the stone pressing mechanism 600. The fixing member 670 is fixed. Each regulating member 660 is an L-shaped plate-like member disposed so as to be positioned between each pair of coil springs 630, and a bent tip portion 661 at the tip thereof is provided at the downstream end of each stone holder 510, 520. Supports the lower surface. By the coil spring 630 interposed between the main body 610 of the stone pressing mechanism 600 and each of the stone holders 510 and 520, the lower surface of the downstream end of each of the stone holders 510 and 520 is urged to the bending tip portion 661 of the regulating member 660. ing. The regulating member 660 is made of, for example, a stainless steel plate.

  FIG. 14 is a schematic diagram for explaining the elastic support action of the stone holder by the stone pressing mechanism of the present embodiment.

  That is, as shown in FIG. 14A, the stone pressing mechanism 600 supports each stone holder 510, 520 with two plate springs 620, two coil springs 630, and a regulating member 660. The stone holders 510 and 520 for holding the divided stones 410 and 420 are supported by the bending of the restriction member 660 made of stainless steel and the elastic force of the plate spring 620 and the coil spring 630, so that the chuck surface of the chuck table is ground. Even if debris adheres, there is no portion that drowns as in the past. Therefore, the movement of the divided stones 410 and 420 is not restricted, and these can be uniformly pressed against the chuck surface.

  When the divided stone 410 (420) is pressed against the chuck surface 210 of the chuck table 200 by the stone pressing mechanism 600, a force in the lateral direction (rotational direction) due to the rotation of the chuck table 200 is applied to the divided stone 410 (420). Then, as shown in FIG. 14B, the force in the table rotating direction acts in a direction in which the leaf spring 620 is bent and extended, and also acts to compress the coil spring 630. At this time, the leaf spring 620 acts in a direction to return to a straight shape, and the coil spring 630 acts in an extending direction, so that the strength is sufficient. Further, the force in the radial direction (perpendicular to the paper surface) of the chuck surface due to the oscillating operation of the cleaner stone 500 acts on the leaf spring 620, but since the width dimension of the leaf spring 620 can be set large, there is no problem in strength. .

  FIG. 15 is a schematic diagram for explaining the relationship between the cleaner stone arrangement and the swing stroke in the present embodiment.

  As shown in FIG. 15, the total length L of the cleaner stone 400 including the two divided stones 410 and 420 is set to be equal to or larger than the radius CR of the chuck table 200. Further, the extended end portion 430 of the cleaner stone 400 is set to protrude slightly outward in the radial direction from the outer peripheral portion 211 of the chuck surface 210 of the chuck table 200, and the cleaner stone 400 is landed on the chuck surface 210. Sometimes, the extended end 430 is positioned on the surface of the outer shell 230 of the chuck table 200.

  As described above, the chuck surface 210 that adsorbs the silicon wafer 150 is the surface of the porous ceramic portion 240, and a dense ceramic is used for the outer shell portion (outer peripheral portion and bottom surface) 230. In the present embodiment, the chuck table 200 for a wafer having a diameter of 300 mmφ (radius WR 150 mm, and the radius CR of the chuck table 200 is 159 mm. If the swing stroke ST of the cleaner stone 400 is 5 mm, an allowance of 6 mm is considered. The total length of the cleaner stone 400 is 165 mm.

  The stone pressing mechanism 600 includes an oscillating means (see FIG. 16) for reciprocating (swinging) the cleaner stone 400 held by the stone holder 500 on the chuck surface 210 of the chuck table 200 in the radial direction of the chuck surface 210. Is provided. Examples of the oscillating means include a rack and pinion driven by a cylinder device or a servo motor.

  During the oscillating operation by the oscillating means, the extended end portion 430 of the cleaner stone 400 does not protrude toward the outer peripheral side of the chuck table 200 but protrudes toward the center of the chuck surface 210. When protruding to the outer peripheral side of the chuck table 200, the outer peripheral side of the chuck table 200 has a high rotational speed, so that a step is generated at the protruding portion. When protruding to the center side of the chuck surface 210, the rotational speed of the center portion of the chuck surface 210 is slow and the amount of stone wear is very small, so that almost no step is generated at the protruding portion.

  The swing stroke ST of the cleaner stone 400 is set to be equal to or less than the distance ΔR between the radius CR of the chuck table 200 and the radius WR of the silicon wafer 150. In this embodiment, since ΔR is 9 mm, the swing stroke of 5 mm satisfies this condition. Since the extended end portion 430 of the cleaner stone 400 is positioned slightly inside (radially centered) with respect to the outer peripheral portion of the chuck table 200, the silicon wafer 150 is attracted when the cleaner stone 400 swings and moves to the center side. If the extended end portion 430 of the cleaner stone 400 is positioned on the radially outer side than the chuck surface 210, the cleaner stone 400 always comes into contact with the chuck surface 210 that is the suction surface of the silicon wafer 150. Therefore, the entire chuck surface 210 to which the silicon wafer 150 is attracted can be cleaned uniformly.

  FIG. 16 is a schematic diagram for schematically explaining the operation of the chuck table cleaning device of the present embodiment. In addition, in FIG. 16, the operating state of each cylinder is shown.

  As shown in FIG. 16, the chuck table cleaning device 300 of this embodiment includes a cleaner shift cylinder 710 that moves the cleaner stone 400 held by the stone holder 500 forward and backward in the standby position in the vertical direction, A swivel cylinder 720 that swivels (advances and retreats) the cleaner stone 400 directly above the chuck table 200 and presses the cleaner stone 400 held by the stone holder 500 on the chuck surface of the chuck table 200 (landing). Alternatively, a cleaner pressing cylinder 730 for retracting and the above-described oscillating means 740 are provided.

  The chuck table cleaning apparatus 300 according to the present embodiment starts the rotation of the chuck table 200 after the cleaner stone 400 is landed on the chuck surface 210 of the chuck table 200 by the pressing cylinder 730 provided in the stone pressing mechanism 600. . Further, after the rotation of the chuck table 200 is stopped, the cleaner stone 400 is retracted from the chuck surface 210. Specifically, the operation of the chuck table cleaning apparatus 300 of the present embodiment will be described with reference to FIG.

  FIG. 17 is an explanatory diagram showing an operation sequence of the chuck table cleaning device of the present embodiment. Note that the horizontal axis in FIG. 17 is the time axis.

  As shown in FIG. 17, first, after closing the shutter of the container that accommodates the cleaning device 300, chuck cleaning (cleaning step) is started. First, supply of chuck water is started (ON), the cleaner shift cylinder 710 is advanced, and the cleaner pressing cylinder 730 is retracted.

  Next, while the cleaner pressing cylinder 730 remains in the retracted state, the turning cylinder 720 is advanced and the supply of cleaner water is started (ON). Then, the cleaner pressing cylinder 730 is pressed and the cleaner stone 400 is landed on the chuck surface 210 of the chuck table 200.

  After the cleaner stone 400 has landed on the chuck surface 210, the chuck table 200 starts rotating, and in synchronization with this, the forward / backward oscillating operation is started along the radial direction of the chuck surface 210.

  After a predetermined time has elapsed, the oscillating operation is terminated and the supply of chuck water is stopped (OFF). Then, the rotation of the chuck table 200 is stopped.

  After the rotation of the chuck table 200 is stopped, the cleaner pressing cylinder 730 is retracted, and the cleaner stone 400 is retracted from the chuck surface 210 of the chuck table 200.

  Thereafter, the cleaner cylinder 400 is moved back immediately above the standby position by the swing cylinder 720, and the supply of cleaner water is stopped (OFF). Then, the cleaner shift cylinder 710 is moved backward, and the cleaner pressing cylinder 730 is pressed to seat the cleaner stone 400 at the standby position, thereby completing the chuck cleaning.

  As described above, according to the chuck table cleaning apparatus 300 of the present embodiment, after the cleaner stone 400 is landed on the chuck surface 210 of the chuck table 200 by the stone pressing mechanism 600, the rotation of the chuck table 200 is started. After the rotation of the chuck table 200 is stopped, the cleaner stone 400 is retracted from the chuck surface 210. Therefore, the cleaner stone is inclined when the cleaner stone is landed on the chuck surface 210 or retracted from the chuck surface 210. In addition, since the chuck table 200 is before the rotation starts or after the rotation is stopped, the partial wear and damage of the chuck surface 210 due to the edge portion of the cleaner stone can be prevented.

  As described above, according to the chuck table cleaning apparatus 300 of the present embodiment, uniform cleaning can be performed on the entire chuck surface 210 of the chuck table 200, and ring-shaped residual wear or uneven wear is caused on the chuck surface 210. Occurrence can be prevented, and wear damage on the chuck surface by the edge portion of the cleaner stone 400 can be prevented.

It is the top view and schematic which explain arrangement | positioning of the cleaner stone of the conventional chuck table washing | cleaning apparatus. It is a schematic diagram of the chuck surface shape of a chuck table. It is a perspective view which shows the elastic support structure of the conventional stone holder. It is the schematic explaining the malfunction of the elastic support structure of the conventional stone holder. It is the schematic explaining the malfunction which arises by the relationship between the conventional cleaner stone arrangement | positioning and a rocking | fluctuation stroke. It is the schematic explaining the malfunction at the time of the cleaner stone landing in the conventional chuck table washing | cleaning apparatus. It is a bottom view of one embodiment of a chuck table cleaning device according to the present invention. (A) is a side view on the radially outer side of the chuck table cleaning device of the present embodiment, and (b) is a side view on the radial center side. It is a rear view of the chuck table cleaning apparatus of this embodiment. It is the schematic of the state which landed the cleaner stone on the chuck | zipper surface of a chuck table. It is the top view and side view of the cleaner stone in this embodiment. It is the top view and side view of the conventional cleaner stone. It is the top view and side view which illustrate the modification of the cleaner stone in this embodiment. It is the schematic explaining the elastic support effect | action of the stone holder by the stone pressing mechanism of this embodiment. It is the schematic explaining the relationship between the cleaner stone arrangement | positioning and rocking | fluctuation stroke in this embodiment. It is the schematic explaining the action | operation of the chuck table washing | cleaning apparatus of this embodiment typically. It is explanatory drawing which shows the operation | movement sequence of the chuck table cleaning apparatus of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Grinding device, 200 ... Chuck table, 210 ... Chuck surface, 211 ... Outer peripheral edge of chuck surface, 300 ... Chuck table cleaning device, 400 ... Cleaner stone, 410, 420 ... Split stone, 500, 510, 520 ... Stone Holder: 600: Stone pressing mechanism, L: Total length of cleaner stone, R: Radius of chuck surface, D: Swing stroke of cleaner stone, ΔR: Distance between extended end of cleaner stone and outer peripheral edge of chuck surface .

Claims (3)

A rotatable chuck table (200) for vacuum chucking the wafer (150);
Cleaner Stone (400),
A stone pressing mechanism (600) for elastically supporting the cleaner stone (400) and landing the cleaner stone (400) on the chuck surface (210) of the chuck table (200);
With
The stone pressing mechanism (600) includes a stone holder (500) on which the cleaner stone (400) is mounted, and an upstream end portion of the stone holder (500) in the table rotation direction toward the upstream side in the rotation direction. A chuck table cleaning device (300) elastically supported by an extended cantilever leaf spring (621, 622) so as to elastically approach and separate from the chuck surface (210). The chuck table cleaning device (300) according to claim 1,
The chuck table cleaning device in which the stone pressing mechanism (600) elastically supports the stone holder (500) at the downstream end in the table rotation direction so as to elastically approach and separate from the chuck surface (210). (300). The chuck table cleaning device (300) according to claim 2,
In the stone pressing mechanism (600), the stone holder (500) on the downstream side in the table rotation direction is a coil spring (630) for urging the stone holder (500) toward the chuck table, and the stone holder (500). A chuck table cleaning device elastically supported by a regulating member (660) for regulating movement toward the chuck table.

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