JP7222721B2 - cleaning mechanism - Google Patents

Description

The present invention relates to a cleaning mechanism for cleaning the lower surface of a plate-like work.

A grinding apparatus that grinds a plate-shaped work such as a semiconductor wafer held on a chuck table with a grinding wheel removes the plate-shaped work from a cassette that stores the plate-shaped work on a shelf, and removes the plate-shaped work from a conveying means such as a suction pad. The workpiece is conveyed to the chuck table. Here, if dust adheres to the lower surface of the plate-like work held by the chuck table, the dust will be interposed between the lower surface of the plate-like work and the holding surface of the chuck table, and the plate-like work will be spread to a uniform thickness. There is a problem that it cannot be ground.

Therefore, as disclosed in Japanese Unexamined Patent Application Publication No. 2002-100001, there is a grinding apparatus equipped with a cleaning mechanism that jets cleaning water onto the lower surface of a plate-like workpiece and brings a brush into contact with the lower surface to clean the lower surface.

Japanese Unexamined Patent Application Publication No. 2011-18802

However, there is a problem that the dust of the cleaned plate-like work adheres to the brush of the cleaning mechanism, and the dust adhering to the brush adheres to the newly washed plate-like work next time.
Therefore, in the cleaning mechanism for cleaning the lower surface of the plate-like work, there is a problem of not cleaning the lower surface of the plate-like work with a dust-attached brush.

The present invention for solving the above-mentioned problems is a cleaning mechanism for cleaning the lower surface of a plate-shaped work held by holding means, comprising a tub formed in a concave shape by a bottom plate and a side plate, and a bucket in the center of the bottom plate. A supply port formed to supply water into the tub, and a brush arranged in the tub by aligning the center of the bottom plate with the center of the bottom plate. The brush is covered with a surface of water which is located at a predetermined distance higher than the end surface and rises above the upper surface of the side plate due to the surface tension of the water stored in the tub. It is a cleaning mechanism that cleans the ends of the hair.

The cleaning mechanism according to the present invention includes a tub formed in a concave shape by a bottom plate and a side plate, a supply port formed in the center of the bottom plate for supplying water into the tub, and a center of the bottom plate aligned with the center of the tub. The upper surface of the brush, which is the tip of the brush, is located at a position higher than the upper end surface of the side plate by a predetermined distance. The cleaning water raised above the upper end surface of the side plate due to surface tension flows over the tips of the brushes from the center of the brush toward the outer periphery, so that the dust adhering to the tips of the brushes can be washed away. Therefore, in subsequent cleaning of the lower surface of a new plate-shaped work, it is possible to prevent the situation from washing the lower surface of the plate-shaped work with a dust-attached brush. In addition, even during cleaning of the plate-like work, since the cleaning water flows from the center of the brush toward the outer peripheral side along the boundary between the brush and the lower surface of the plate-like work, it is possible to prevent dust from adhering to the plate-like work and the brush. can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows an example of the grinding apparatus provided with the washing|cleaning mechanism which concerns on this invention. It is a perspective view which shows an example of the tub and brush of a washing|cleaning mechanism. It is a perspective view which shows another example of a brush. FIG. 4 is a cross-sectional view for explaining a state in which cleaning of the lower surface of the plate-like work is started; FIG. 4 is a cross-sectional view for explaining a state in which the lower surface of a plate-like work is being washed; FIG. 10 is a cross-sectional view for explaining a state in which cleaning of the lower surface of the plate-like work is started in parallel with the operation of conveying the plate-like work from the temporary placement area to the chuck table; FIG. 10 is a cross-sectional view for explaining a state in which the lower surface of the plate-like work is being cleaned in parallel with the operation of conveying the plate-like work from the temporary placement area to the chuck table;

A grinding apparatus 1 shown in FIG. 1 is equipped with a cleaning mechanism 8 according to the present invention, and is an apparatus for grinding a plate-like workpiece W held on a chuck table 30 by grinding means 4 . The front side (−X direction side) of the base 10 of the grinding apparatus 1 is a loading/unloading area A in which the plate-like workpiece W is loaded/unloaded to/from the chuck table 30 , and the rear side of the base 10 is a loading/unloading area A. (+X direction side) is a processing region B in which the plate-like workpiece W held on the chuck table 30 by the grinding means 4 is ground.
The grinding apparatus in which the cleaning mechanism 8 according to the present invention is arranged has two shafts, rough grinding means and finish grinding means, as grinding means, and a chuck table 30 is positioned below each grinding means by a rotating turntable. It may be configured. Also, the cleaning mechanism 8 may be arranged in a cutting device, a polishing device, a laser processing device, or the like, in addition to the grinding device.

A plate-shaped workpiece W shown in FIG. 1 is, for example, a circular semiconductor wafer, and a plurality of devices (not shown) are formed on the lower surface Wa thereof. For example, a protective tape (not shown) is adhered to the lower surface Wa of the plate-shaped work W, and the lower surface Wa is protected by the protective tape. The upper surface Wb of the plate-like work W is a surface to be ground, and the plate-like work W is held on the chuck table 30 with the upper surface Wb facing upward.

For example, a first cassette mounting portion 150 and a second cassette mounting portion 151 are provided on the front surface of the base 10 on the -X direction side. A first cassette 150a containing plate-like works W is mounted, and a second cassette 151a containing plate-like works W after processing is mounted on a second cassette mounting portion 151. FIG.

A robot 155 is disposed behind the first cassette 150a for unloading the plate-shaped work W before processing from the first cassette 150a and loading the processed plate-shaped work W into the second cassette 151a. there is A temporary placement area 152 is provided at a position adjacent to the robot 155 , and an alignment means 153 is provided in the temporary placement area 152 . The alignment means 153 aligns (centers) the plate-shaped work W carried out from the first cassette 150a and placed on the temporary placement area 152 at a predetermined position by means of a plurality of diameter-reducing pins.

At a position adjacent to the positioning means 153 , a holding means 14 is provided for holding the upper surface Wb of the plate-like work W before processing and carrying it into the chuck table 30 . The holding means 14 includes a horizontally extending arm portion 140 and a suction pad 141 fixed to the lower surface side of one end of the arm portion 140 . The arm portion 140 is connected to a turning movement means 143 consisting of a rotating shaft or the like and an elevating means 144 consisting of a cylinder mechanism or the like. The arm part 140 can be moved up and down in the vertical direction (Z-axis direction) by the elevating means 144 .

The suction pad 141 (see FIG. 4) has, for example, a circular outer shape, and includes a suction portion 141a made of a porous member or the like for sucking the plate-like work W, and a frame 141b supporting the suction portion 141a. The suction portion 141a communicates with a suction source (not shown) such as a vacuum generator, and a suction force generated by suction by the suction source is transmitted to a flat suction surface 141c, which is an exposed surface of the suction portion 141a. , the suction pad 141 sucks and holds the plate-like work W on the suction surface 141c.

As shown in FIG. 1, next to the holding means 14, there is provided a carry-out means 16 capable of sucking and holding the plate-shaped work W after processing and capable of turning. Note that the holding means 14 and the carry-out means 16 may be an edge clamping mechanism that grips the outer periphery of the plate-like work W. As shown in FIG.
At a position adjacent to the carry-out means 16, a single-wafer type spinner cleaning means 156 for cleaning the processed plate-shaped work W carried from the chuck table 30 by the carry-out means 16 is arranged. The plate-like work W cleaned by the spinner cleaning means 156 is carried into the second cassette 151a by the robot 155. As shown in FIG.

The chuck table 30, which is arranged on the base 10 of the grinding apparatus 1 and holds the plate-like work W, has, for example, a circular outer shape and is made of a porous member or the like that communicates with a suction source (not shown). It has a holding surface 30a for suction holding. The chuck table 30 is surrounded by a cover 39, and X-axis feeding means (not shown) provided under the cover 39 and a bellows cover 39a connected to the cover 39 moves the base 10 in an X direction. It is reciprocatingly movable in the axial direction. Also, the chuck table 30 is rotatable around an axis in the Z-axis direction.

A column 12 is erected on the rear side (+X direction side) of the processing region B, and the front surface of the column 12 on the -X direction side is the Z-axis direction for separating or approaching the grinding means 4 to the chuck table 30. Grinding feeding means 2 for feeding to grinding is arranged. The grinding feed means 2 includes a ball screw 20 having an axis in the Z-axis direction (vertical direction), a pair of guide rails 21 arranged parallel to the ball screw 20, and connected to the upper end of the ball screw 20 to rotate the ball screw 20. an elevating plate 23 whose inner nut is screwed onto the ball screw 20 and whose side portion is in sliding contact with the guide rail 21; and a holder 24 connected to the elevating plate 23 and holding the grinding means 4. When the ball screw 20 is rotated by the ball screw 20, the elevating plate 23 is guided by the guide rail 21 and reciprocates in the Z-axis direction, and the grinding means 4 held by the holder 24 is fed for grinding in the Z-axis direction. .

The grinding means 4 for grinding the plate-like workpiece W held on the chuck table 30 includes a rotary shaft 40 whose axial direction is the Z-axis direction, a housing 41 that rotatably supports the rotary shaft 40, and the rotary shaft 40. It comprises a motor 42 that drives to rotate, an annular mount 43 connected to the lower end of the rotating shaft 40, and a grinding wheel 44 that is detachably connected to the lower surface of the mount 43.

The grinding wheel 44 includes a wheel base 441 and a plurality of substantially rectangular parallelepiped grinding wheels 440 annularly arranged on the bottom surface of the wheel base 441 . The grinding wheel 440 is formed by bonding diamond grains or the like with resin bond, vitribond, metal bond, or the like, for example. The shape of the grinding wheel 440 may be formed integrally in an annular shape.

Inside the rotating shaft 40 , a flow path (not shown) is formed to pass through the rotating shaft 40 in the axial direction (Z-axis direction). This flow path passes through the mount 43 and is open at the bottom surface of the wheel base 441 so that grinding water can be jetted toward the grinding wheel 440 .

The cleaning mechanism 8 according to the present invention, as shown in FIG.
The cleaning mechanism 8 shown in FIGS. 1 and 2 for cleaning the lower surface Wa of the plate-like workpiece W held by the holding means 14 includes a circular bottom plate 800 in the illustrated example, and a bottom plate 800 integrally moving from the outer periphery of the bottom plate 800 in the +Z direction. It has a tub 80 consisting of a side plate 801 rising from the bottom.

For example, one supply port 81 for supplying water into the tub 80 is formed through the center of the bottom plate 800 . The supply port 81 communicates with a supply channel 850 (see FIG. 4) formed in a support column 85 that supports the tub 80 on the base 10 shown in FIG. One end of a supply pipe 893 such as a metal pipe or a flexible resin tube communicates via a joint 851 attached to the side surface. The other end of the supply pipe 893 communicates via an open/close valve 890 with a water supply source 89 which is composed of a pump or the like and capable of supplying cleaning water (for example, pure water).

The cleaning mechanism 8 includes a brush 83 arranged in the tub 80 so that the center of the bottom plate 800 and the center of the brush 83 are aligned with each other. The brush 83 is made of, for example, elastic resin fibers (for example, nylon) that are formed into straight hairs and densely packed. It is planted on the upper surface of the flat brush plate 831 . The lower surface of the brush plate 831 is adhered or screwed onto the bottom plate 800 of the tub 80 , and the cleaning water supplied to the brush 83 from the supply port 81 overflows from the central circular opening 830 of the brush 83 .

For example, the thickness of the resin fibers of the brush 83 is 0.1 mm, and the height of the brush 83 (the length of the resin fibers) is 10 mm. As shown in FIG. 4, the upper surface 83a, which is the tip of the brush 83 attached to the tub 80, is positioned higher than the upper end surface 801a of the side plate 801 of the tub 80 by a predetermined distance H. As shown in FIG. The resin fibers of the brush 83 may have a tapered shape in which the diameter is gradually reduced toward the ends of the bristles and the ends are sharpened. The predetermined distance H is set to 2 mm, for example, but is not limited to this value. The diameter of the tub 80 is also taken into consideration when setting the value so that the rising water surface can cover the top surface 83a of the brush 83, which is the bristle tip.
It is preferable that the diameter of the brush 83 is set larger than the diameter of the plate-like workpiece W as in this embodiment.

The cleaning mechanism 8 may include a brush 87 shown in FIG. 3 instead of the brush 83 shown in FIGS. The brush 87 is made of, for example, elastic resin fibers (for example, nylon) that are formed into straight hairs and densely packed. It is planted on the upper surface of the shaped brush plate 871 . The lower surface of the brush plate 871 is glued or screwed onto the bottom plate 800 of the tub 80 shown in FIG. At the center of the brush plate 871, one or a plurality of water jets 874 are formed in the gaps between the bristles. The washing water supplied to the brush 87 from 81 overflows. An upper surface 87a, which is the bristle tip of the brush 87 attached to the tub 80, is located higher than the upper end surface 801a of the side plate 801 of the tub 80 by a predetermined distance (for example, 2 mm).

The operation of the grinding device 1 and the cleaning mechanism 8 when grinding the upper surface Wb of the plate-like workpiece W using the grinding device 1 shown in FIG. 1 will be described below.

To grind the upper surface Wb of the plate-like work W, the robot 155 first pulls out one plate-like work W from the first cassette 150 a and moves the plate-like work W to the temporary placement area 152 . Next, the turning means 143 turns the suction pad 141 in the horizontal direction so that the upper surface Wb of the plate-like work W on the temporary placement area 152 faces the suction surface 141c of the suction pad 141 shown in FIG. In addition, the suction pad 141 is positioned above the plate-like work W so that the center of the upper surface Wb of the plate-like work W and the center of the suction pad 141 substantially coincide with each other.

Next, the lifting means 144 lowers the suction pad 141 to bring the suction surface 141c into contact with the upper surface Wb of the plate-shaped work W. As shown in FIG. In this state, a suction source (not shown) generates a suction force, and the suction pad 141 to which the suction force is transmitted suction-holds the plate-like work W on the suction surface 141c. Next, the lifting means 144 raises the suction pad 141 holding the upper surface Wb of the plate-like work W, and the holding means 14 carries out the plate-like work W from the temporary placement area 152 .

The turning means 143 horizontally turns the suction pad 141 holding the plate-like work W to position the plate-like work W above the cleaning mechanism 8 as shown in FIG. The positioning is performed, for example, so that the center of the brush 83 and the center of the plate-like work W are approximately overlapped.

On the other hand, in the cleaning mechanism 8 shown in FIG. Washing water (for example, pure water) is supplied to the supply pipe 893 from the water supply source 89 , passes through the support column 85 , and flows out from the supply port 81 of the tub 80 onto the brush plate 831 . Then, the cleaning water accumulates in the tub 80, and when the surface of the cleaning water in the tub 80 exceeds the upper end surface 801a of the side plate 801, the water surface rises above the upper end surface 801a of the side plate 801 due to surface tension. In addition, the washing water flows from the center of the opening 830 of the brush 83 toward the outer peripheral side on the water surface, and the washing water overflows from the tub 80 .
The top surface 83a of the brush 83 located at a position higher than the top end surface 801a of the side plate 801 by a predetermined distance H is covered with the washing water in a raised state due to surface tension.

When the brush 87 shown in FIG. 3 is arranged in the tub 80 instead of the brush 83, similarly, the washing water ejected from the water ejection port 874 accumulates in the tub 80, and the upper end surface 801a of the side plate 801 The upper surface 87a, which is the bristle tip of the brush 87 located at a higher position than the brush 87 by a predetermined distance, is covered with the washing water in a raised state due to surface tension.

With the upper surface 83a of the brush 83, which is the tip of the brush 83, covered with the washing water raised by surface tension, as shown in FIG. The lower surface Wa of the plate-like work W is brought into contact with the upper surface 83a of the brush 83. As shown in FIG. Further, the revolving movement means 143 reciprocates the suction pad 141 in the horizontal direction at a predetermined angle, so that the brush 83 scrapes off dust adhering to the lower surface Wa of the plate-like workpiece W. Even during cleaning of the plate-like work W, the cleaning water flows from the center of the brush 83 toward the outer periphery along the boundary between the upper surface 83a of the brush 83 and the lower surface Wa of the plate-like work W. Dust is prevented from adhering to the brush 83.例文帳に追加Since the opening 830 in the center of the brush 83 moves horizontally relative to the lower surface Wa of the plate-like work W, the bristles of the brush 83 move and hit the entire lower surface Wa of the plate-like work W. Because of the contact, the entire lower surface Wa of the plate-shaped work W is evenly cleaned.

In addition, as shown in FIG. 4, the positioning of the plate-like works W above the cleaning mechanism 8 does not have to overlap each other's centers. That is, as shown in FIG. 6, the plate-like work W is positioned above the cleaning mechanism 8 at a position where the center of the brush 83 and the center of the plate-like work W are displaced, and the upper surface 83a serving as the bristle tip of the brush 83 is positioned. The suction pad 141 is lowered to a position where the lower surface Wa of the plate-like work W is brought into contact, and as shown in FIG. Cleaning may be completed by separating the plate-like workpiece W upward from the upper surface 83a. That is, instead of reciprocating the suction pad 141 at a predetermined angle in the horizontal direction as described above, the lower surface Wa of the plate-like workpiece W may be cleaned by horizontally moving the suction pad 141 in one direction. That is, during the movement of the plate-like work W sucked and held by the suction pad 141 from the temporary placement area 152 shown in FIG. The cleaning may be performed in parallel so that the processing time is not increased due to the cleaning of the lower surface Wa of the plate-like workpiece W.

At least one of the brush 83 of the cleaning mechanism 8 and the suction pad 141 of the holding means 14 is configured to be rotatable about the axis in the Z-axis direction by means of a rotation mechanism. The lower surface Wa may be washed by rotating at least one of the suction pad 141 that is held by suction.
Further, the lower surface Wa of the ground plate-like workpiece W held by the carry-out means 16 may be cleaned by the cleaning mechanism 8 .
It should be noted that cleaning and removal of dust adhering to the lower surface Wa of the plate-like work W is carried out in substantially the same manner even when the brush 87 shown in FIG. 3 is used.

After cleaning the lower surface Wa of the plate-like work W by the brush 83 for a predetermined time, the plate-like work W is lifted in the +Z direction by the elevating means 144, and as shown in FIG. become separated. As a result, even if dust adheres to the upper surface 83a, which is the bristle tip of the brush 83, due to the cleaning of the lower surface Wa of the plate-like workpiece W, the dust will be removed from the center of the opening 830 of the brush 83 on the water surface of the tub 80 toward the outer peripheral side. Due to the flow of the cleaning water, the cleaning water, which has been raised due to surface tension, overflows from the tub 80, and the dust on the upper surface 83a of the brush 83 is washed off. Therefore, when cleaning the lower surface Wa of the new plate-like work W thereafter, it is possible to prevent the lower surface Wa of the plate-like work W from being washed with the dust-attached brush 83 .
Note that even when the brush 87 shown in FIG. 3 is used, the wash water that is swollen due to surface tension overflows from the tub 80 due to the flow of the wash water from the center of the brush 87 toward the outer periphery on the water surface of the tub 80 . As it goes out, the dust adhering to the upper surface 87a of the brush 87 is washed off.

The holding means 14 shown in FIG. 1 moves the plate-like work W whose lower surface Wa has been cleaned onto the chuck table 30, and the holding surface 30a sucks and holds the plate-like work W with the upper surface Wb facing upward. . Next, the chuck table 30 holding the plate-like work W moves in the +X direction to below the grinding means 4 . The grinding means 4 is fed in the -Z direction by the grinding feed means 2, and the grinding wheel 440, which rotates with the rotation of the rotary shaft 40, contacts the upper surface Wb of the plate-like workpiece W, thereby performing grinding. During grinding, as the chuck table 30 rotates, the plate-like work W held on the holding surface 30a also rotates, so the grinding wheel 440 grinds the entire upper surface Wb of the plate-like work W. . In addition, grinding water is supplied to the contact portion between the grinding wheel 440 and the plate-like work W to cool and wash the contact portion. Since the lower surface Wa of the plate-like work W is cleaned by the cleaning mechanism 8 and is free of dust, dust is interposed between the lower surface Wa of the plate-like work W and the holding surface 30a of the chuck table 30. The plate-like workpiece W can be ground to a desired uniform thickness without cutting.

After grinding the plate-like work W to a desired thickness, the grinding means 4 is lifted by the grinding feeding means 2 to separate from the plate-like work W, and the chuck table 30 is moved in the -X direction to carry out means 16. positioned in the vicinity of Next, the plate-like work W is transported to the spinner cleaning means 156 by the unloading means 16 . The upper surface Wb of the plate-shaped work W is cleaned by the spinner cleaning means 156 . The plate-like workpiece W whose upper surface Wb has been cleaned is accommodated in the second cassette 151a by the robot 155. As shown in FIG.

It goes without saying that the cleaning mechanism 8 according to the present invention is not limited to the above embodiment, and may be implemented in various forms within the scope of the technical idea. Moreover, the configuration of the grinding apparatus 1 illustrated in the accompanying drawings is not limited to this, and can be changed as appropriate within the range in which the effects of the present invention can be exhibited.

W: plate-shaped work Wa: lower surface of plate-shaped work Wb: upper surface of plate-shaped work 1: grinding device 10: base 12: column 150a: first cassette 151a: second cassette 155: robot 152: temporary placement area 153 : positioning means 156: spinner cleaning means 14: holding means 140: arm portion 141: suction pad 141c: suction surface 143: turning movement means 144: lifting means 16: carry-out means 30: chuck table 30a: holding surface 2: grinding feed Means 20: Ball screw 22: Motor 4: Grinding means 40: Rotating shaft 42: Motor 44: Grinding wheel 440: Grinding wheel 8: Cleaning mechanism 80: Tub 800: Bottom 801: Side plate 801a: Upper end surface of side plate 81: Supply port 85 : Support column 850: Supply path 851: Joint 89: Water supply source 890: Open/close valve 893: Supply pipe 83: Brush 83a: Upper surface that serves as the tip of the brush 831: Brush plate 830: Opening 87: Brush 87a: Brush Top surface to be bristles 871: Brush plate

Claims (1)

A cleaning mechanism for cleaning the lower surface of the plate-shaped work held by the holding means,
A tub formed in a concave shape by a bottom plate and a side plate, a supply port formed in the center of the bottom plate for supplying water into the tub, and a brush arranged in the tub by aligning the center of the bottom plate with the center of the tub. and
The upper surface of the brush, which is the bristle tip, is located at a position higher than the upper end surface of the side plate by a predetermined distance,
A washing mechanism in which a surface of water raised from the upper end surface of the side plate by the surface tension of the water stored in the tub covers the brush, and water flows over the submerged upper surface of the brush to wash the bristles of the brush.

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