JP5345457B2 - Grinding equipment - Google Patents

Description

  The present invention relates to a grinding apparatus for grinding a workpiece such as a semiconductor wafer.

  In the semiconductor device manufacturing process, a work is divided into a plurality of rectangular areas by dividing lines called streets arranged in a grid on the surface of the work having a substantially disk shape, and a semiconductor circuit is formed in each of the rectangular areas. To do. Then, individual semiconductor chips are manufactured by separating the work on which the semiconductor circuit is formed along the streets. Similarly, workpieces with gallium nitride compound semiconductors laminated on the surface of sapphire substrates are also manufactured as optical devices such as individual light emitting diodes and laser diodes by separating along the streets. Widely used.

  In order to reduce the size and weight of the semiconductor chip, the workpiece separated in this way is ground at the back surface before being separated along the street and processed to a predetermined thickness. In this backside grinding of the workpiece, the surface of the workpiece is usually held by holding means, and this grinding tool is held while rotating a grinding tool to which a grinding stone such as diamond abrasive grains is fixed with a suitable bond such as a resin bond. This is done by pressing against the back side of the workpiece on the means. Specifically, for example, a grinding device having a device configuration disclosed in Patent Document 1 is known.

JP-A-10-86048

  By the way, since the back surface grinding of the workpiece is performed while holding the surface of the workpiece (held surface) and pressing the back surface of the held workpiece as described above, if foreign matter adheres to the held surface, There was a problem that it sometimes had an adverse effect such as breakage of the workpiece. For this reason, it is desirable to provide a cleaning mechanism in the grinding apparatus to clean the held surface of the workpiece before grinding. Here, the grinding equipment has electrical components mounted inside its housing, etc., and when the grinding device is equipped with a cleaning mechanism, if the cleaning liquid scatters around the cleaning mechanism, the electrical components will submerge and break down. Can occur.

  The present invention has been made in view of the above, and an object of the present invention is to provide a grinding apparatus capable of sufficiently cleaning a held surface of a workpiece before grinding while preventing scattering of cleaning liquid around the object. And

  In order to solve the above-described problems and achieve the object, a grinding apparatus according to the present invention includes a holding unit that holds a surface to be held of a workpiece, and a grinding unit that grinds the workpiece held by the holding unit. A grinding apparatus comprising: positioning means for positioning the workpiece; and conveying means for conveying the workpiece between the positioning means and the holding means while holding the workpiece on a conveyance surface, Pre-cleaning means for cleaning the held surface of the work before the work is transported to the holding means, and the pre-cleaning means in the middle of the transport path of the transport means. Cleaning liquid splash preventing means disposed between the positioning means and preventing the cleaning liquid from splashing toward the positioning means generated during cleaning by the preliminary cleaning means. The stage has a cleaning liquid stored therein, a water tank in which the work held on the transfer surface of the transfer means is submerged in the cleaning liquid, and is disposed in the water tank, and the work is submerged in the cleaning liquid in the water tank. And a brush rotation drive mechanism for rotating the brush along the held surface when the cleaning liquid is scattered, and the cleaning liquid splash preventing means is configured to splash the cleaning liquid. A shutter that shuts off the cleaning liquid, a shutter driving mechanism that displaces the shutter to a non-operating position that allows the transport means to pass, and a shutter driving mechanism that displaces the cleaning liquid, and the shutter that is displaced to the non-operating position. In a position near the passage of the conveying means, a nozzle arranged with an ejection port directed toward the conveying surface, and the conveying means conveys the workpiece to the holding means. After, when moving from said prewash section side to the positioning means side, characterized by having a a gas injection mechanism for injecting a gas toward the conveying surface from the ejection nozzle.

  In the grinding device according to the present invention, in the above invention, a supply port for supplying the cleaning liquid into the water tank and a discharge port for discharging the cleaning liquid in the water tank to the outside are formed at the bottom of the water tank. Features.

  According to the present invention, it is possible to clean the surface to be held of the work held by the holding means during the grinding process, and to remove foreign matters adhering to the surface to be held. At this time, it is possible to prevent the cleaning liquid from scattering to the positioning means side. Further, when the conveying means for conveying the workpiece moves from the pre-cleaning means side to the positioning means side, gas can be blown onto the conveying surface, and the cleaning liquid adhering to the conveying surface can be removed. Therefore, there is an effect that the surface to be held of the workpiece before grinding can be sufficiently cleaned while preventing the cleaning liquid from splashing around, particularly the positioning means side. Here, in a general grinding apparatus, since water is used during grinding by the grinding means, a prevention function is secured on the holding means side.

FIG. 1 is a perspective view showing a configuration example of a grinding apparatus according to the present embodiment. FIG. 2 is an enlarged perspective view showing the periphery of the pre-cleaning means and the cleaning liquid splash preventing means constituting the grinding apparatus. FIG. 3 is a partial cross-sectional view illustrating the configuration of the preliminary cleaning unit and the cleaning liquid splash preventing unit. FIG. 4 is a block diagram showing a configuration example of a control system of the grinding apparatus related to the operations of the pre-cleaning means and the cleaning liquid splash preventing means. FIG. 5A is a partial cross-sectional view for explaining operations of the pre-cleaning unit and the cleaning liquid splash preventing unit. FIG. 5B is a partial cross-sectional view for explaining the operation of the pre-cleaning unit and the cleaning liquid splash preventing unit following FIG.

  Hereinafter, a grinding device which is a form for carrying out the present invention is explained with reference to drawings.

  First, the grinding apparatus of this embodiment will be described. The grinding apparatus according to the present embodiment is for grinding a surface to be ground of a workpiece. The workpiece to be ground by this grinding apparatus has a substantially disk shape, and is formed by, for example, a plurality of devices partitioned on the surface by streets. The grinding device grinds the back surface of the workpiece as the surface to be ground while holding the surface of the workpiece as the surface to be held. In addition, the grinding apparatus according to the present embodiment pre-cleans the surface that is held as the held surface during the grinding process with the back surface of the work as the attracted surface.

Specific examples of the workpiece are not particularly limited. For example, ductility such as silicon wafer, semiconductor wafer such as GaAs, ceramic, glass, sapphire (Al ₂ O ₃ ) -based inorganic material substrate, plate metal, resin, etc. Material, and flatness on the order of micron to submicron (TTV: total thickness variation: the difference between the maximum and minimum values of the entire surface to be ground measured in the thickness direction with the surface to be ground of the workpiece as the reference surface ) Are required.

  FIG. 1 is a perspective view showing a configuration example of a grinding apparatus 1 according to the present embodiment. 2 is an enlarged perspective view showing the periphery of the pre-cleaning means 12 and the cleaning liquid scattering preventing means 15 constituting the grinding apparatus 1, and FIG. 3 shows the configuration of the pre-cleaning means 12 and the cleaning liquid scattering preventing means 15. FIG. 4 is a block diagram showing a configuration example of a control system of the grinding apparatus 1 relating to the operations of the pre-cleaning means 12 and the cleaning liquid splash preventing means 15.

  As shown in FIG. 1, the grinding apparatus 1 includes, for example, a housing 2, two grinding means 3 and 4, for example, three holding means 6 a to 6 c installed on the turntable 5, and cassettes 7 and 8. , Positioning means 9, carrying-in means 10 as conveying means, carrying-out means 11, cleaning means 18, carrying-in / out means 19, pre-cleaning means 12, cleaning liquid scattering preventing means 15, and control means 20. ing.

  The grinding means 3 is a work held on the holding surface 6s while rotating by a motor 3d a grinding wheel 3c having a grinding wheel 3b removably attached to the lower end of a rotating shaft 3a orthogonal to the holding surface 6s of the holding means 6b. The surface to be ground (back surface) is pressed to perform grinding (for example, rough grinding) on the surface to be ground. Similarly, the grinding means 4 is held on the holding surface 6s while rotating the grinding wheel 4c having the grinding wheel 4b detachably attached to the lower end of the rotating shaft 4a orthogonal to the holding surface 6s of the holding means 6c by the motor 4d. This is for applying a grinding process (for example, finish grinding) to the surface to be ground by pressing the surface to be ground of the workpiece.

  Here, the grinding means 3 and 4 are provided so as to be moved up and down by the lifting and feeding means 31 and 41, respectively, and the grinding wheels 3c and 4c having the grinding wheels 3b and 4b are ground surfaces of the workpiece on the holding means 6b and 6c. In contrast, it is configured to be capable of grinding feed.

  The three holding means 6a to 6c on the turntable 5 are arranged at equal intervals with a phase angle of 120 degrees, for example. These holding means 6a to 6c have a chuck table structure provided with a vacuum chuck on the upper surface, and hold the surface to be held (surface) of the workpiece by vacuum suction on a holding surface 6s formed flat. Further, these holding means 6a to 6c are rotationally driven in a horizontal plane by a rotational drive mechanism (not shown) at the time of grinding.

  The turntable 5 is provided on the upper surface of the housing 2 so as to be rotatable in a horizontal plane, and is driven to rotate at an appropriate timing. Then, the turntable 5 rotates the three holding means 6a to 6c by the grinding means 3 (position of the holding means 6b in FIG. 1) and the grinding position by the grinding means 4 (holding means in FIG. 1). 6c) and a carry-in / carry-out position (position of the holding means 6a in FIG. 1).

  The cassettes 7 and 8 are container for work having a plurality of slots. One cassette 7 accommodates the workpiece before grinding, and the other cassette 8 accommodates the workpiece after grinding. The positioning means 9 is a table for temporarily placing the work taken out from the cassette 7 and positioning its center position.

  The carry-in means 10 includes a transfer arm 10a that freely moves up and down in the vertical direction and rotates around a vertical line passing through its base end as a central axis, and a suction pad that holds and holds a workpiece on the transfer arm 10a. 10b is attached and comprised. The carrying-in means 10 sucks and holds the suction target surface (back surface) of the workpiece before grinding positioned by the positioning means 9 and carries it into the pre-cleaning means 12. ) Is pre-cleaned and loaded onto the holding surface 6s of the holding means 6a located at the loading / unloading position. Similarly, the carrying-out means 11 includes a transfer arm 11a that freely moves up and down in the vertical direction and rotates around a vertical line passing through its base end as a central axis, and holds and holds a workpiece on the transfer arm 11a. The suction pad 11b is attached and configured. The unloading means 11 sucks and holds the workpiece after grinding on the holding means 6 a located at the loading / unloading position, and unloads it to the cleaning means 18.

  The pre-cleaning means 12 pre-cleans the surface to be cleaned of the workpiece before grinding at a position before loading with respect to the holding means 6a, and is transported between the positioning means 9 and the holding means 6a positioned at the loading / unloading position. The suction pad 10b that moves by the rotation of the arm 10a and conveys the workpiece is disposed in the middle of the conveyance path indicated by an arrow A1 in FIG. The pre-cleaning means 12 has an opening in the upper part and a water tank 13 in which a cleaning liquid such as pure water is stored in an internal space.

  As shown in FIG. 3, a supply port 131 is formed on the bottom surface of the water tank 13 to connect the internal space of the water tank 13 to the outside and supply the cleaning liquid to the internal space of the water tank 13. As indicated by A2, the cleaning liquid is supplied from the supply port 131 to the internal space of the water tank 13 by a cleaning water supply mechanism (not shown). In addition, a discharge port 132 is formed on the bottom surface of the water tank 13 so as to allow the internal space of the water tank 13 to communicate with the outside and discharge the cleaning liquid stored in the internal space of the water tank 13 to the outside. The discharged cleaning liquid is guided and discharged below the water tank 13 as indicated by an arrow A3 in FIG. Here, the discharge port 132 is provided with a valve 133. When supplying the cleaning liquid, the cleaning liquid is supplied from the supply port 131 with the valve 133 being closed, and when the cleaning liquid is discharged, the valve is driven by a cleaning water discharge mechanism (not shown). 133 is opened. In this water tank 13, the work 30 sucked and held on the suction pad 10b forming the transport surface 101b is a cleaning liquid stored in the internal space by the suction pad 10b descending along the direction indicated by the arrow A11 in FIG. To be submerged.

  The pre-cleaning means 12 includes a brush 14 for cleaning the surface to be cleaned of the workpiece before grinding. As shown in FIG. 2, the brush 14 is configured by brush hairs 14 b radially planted on a substantially disc-shaped support plate 14 a having an area substantially equivalent to a workpiece. In the brush 14, the suction pad 10 b that has moved above the water tank 13 along the direction indicated by the arrow A 12 in FIG. 3 descends along the direction indicated by the arrow A 11, and the workpiece 30 that is suction-held by the suction pad 10 b. Is immersed in the cleaning liquid, the bristles 14b are arranged inside the water tank 13 so as to come into contact with the surface to be cleaned. Specifically, the brush 14 is attached to an upper end of a rotation shaft 134 that is orthogonal to a horizontal plane provided at the bottom of the water tank 13, and the rotation shaft 134 is centered at an appropriate timing by a brush rotation mechanism 121 shown in FIG. 4. It is configured to be rotatable in a horizontal plane.

  As shown in FIG. 2, the cleaning liquid splash preventing means 15 includes a shutter 16 disposed between the positioning means 9 and the preliminary cleaning means 12. On the upper surface of the shutter 16, a plurality of nozzles 17 that eject gas at an appropriate timing by a gas ejection mechanism 152 shown in FIG. 4 are arranged. Each nozzle 17 is arranged so that its injection port is directed upward in the vertical direction, and the suction pad 10b (in detail, it passes above the shutter 16 along the direction indicated by the arrow A12 in FIG. 3). It is configured to be able to inject gas toward the conveyance surface 101b) of the suction pad 10b.

  Here, since a grinding fluid such as pure water is appropriately used when the workpiece is ground by the grinding means 3 and 4, the turntable 5 side on which the holding means 6a to 6c are installed (pre-cleaning toward FIG. 1). The area on the back side of the means 12 has a waterproof structure. On the other hand, in the region of FIG. 1 equipped with cassettes 7 and 8, positioning means 9, carry-in / out means 19 and the like, the area in front of pre-cleaning means 12 is not supposed to use water, and a waterproof function is ensured. Absent. For this reason, when the electrical component is mounted inside the housing 2 corresponding to the front side region, the electrical component is submerged by the entering cleaning liquid. In order to prevent such a situation, the cleaning liquid splash preventing means 15 scatters and blocks the cleaning liquid so that the cleaning liquid used by the pre-cleaning means 12 for pre-cleaning the surface to be cleaned of the workpiece does not enter the positioning means 9 side. To prevent.

  Specifically, the shutter 16 is moved up and down along the direction indicated by the arrow A13 in FIG. 3 by the shutter drive mechanism 151 shown in FIG. 4, and the height position (the position of the upper surface) is a one-dot chain line in FIG. As shown in FIG. 3, the working position protrudes upward from the upper end of the water tank 13, and as shown by a solid line in FIG. 3, the working position is displaced from the working position to allow passage of the loading means 10 above the shutter 16. It is configured to be possible. The action position is set to a position where the height position is sufficiently higher than the upper end of the water tank 13. On the other hand, the non-operation position is set to a height position where the height position is substantially the same as the upper end of the water tank 13.

  The cleaning liquid splash prevention means 15 configured as described above functions to prevent the cleaning liquid from splashing toward the positioning means 9 at the time of preliminary cleaning, and when the suction pad 10b passes, the transport surface of the suction pad 10b at the time of preliminary cleaning. It fulfills the function of removing the cleaning liquid adhering to 101b.

  Returning to FIG. The cleaning means 18 cleans the workpiece after grinding, and removes contamination such as grinding dust adhering to the ground surface to be ground.

  The carry-in / out means 19 is, for example, a robot arm 19a having a U-shaped hand, and conveys the work surface to be ground by suction with the robot arm 19a. Specifically, the carry-in / out means 19 carries the workpiece before grinding from the cassette 7 to the positioning means 9 and carries the workpiece after grinding into the cassette 8 from the cleaning means 18.

  The control means 20 is composed of a microcomputer or the like with a built-in memory for holding various data necessary for the operation of the grinding apparatus 1, and controls the operation of each part constituting the grinding apparatus 1 to control the grinding apparatus 1 in an integrated manner. To do. In the present embodiment, the control means 20 pre-cleans the surface to be cleaned of the workpiece before grinding carried into the pre-cleaning means 12 by the suction pad 10b of the carry-in means 10, and the cleaning liquid from the pre-cleaning means 12 The operations of the pre-cleaning means 12 and the cleaning liquid splash preventing means 15 are controlled so as to prevent the splashing of the cleaning liquid. Specifically, as shown in FIG. 4, the control means 20 drives the brush rotation mechanism 121 to control the operation of the pre-cleaning means 12, and drives the shutter drive mechanism 151 and the gas injection mechanism 152 to wash the cleaning liquid. The operation of the scattering prevention means 15 is controlled.

  Here, the operations of the pre-cleaning means 12 and the cleaning liquid splash preventing means 15 controlled by the control means 20 will be described. FIGS. 5A and 5B are partial cross-sectional views illustrating the operations of the pre-cleaning unit 12 and the cleaning liquid splash preventing unit 15.

  As shown in FIG. 5A, the suction pad 10 b of the carry-in means 10 moves above the water tank 13 during the preliminary cleaning. Then, after the upper surface height of the shutter 16 is raised to the operating position by the shutter drive mechanism 151, the suction pad 10b is lowered into the water tank 13. As a result, the workpiece 30 before being ground, in which the suction surface is sucked and held by the suction pad 10b (conveying surface 101b), is inserted from the upper opening of the water tank 13, and submerged in the cleaning liquid stored in the internal space. The surface 30a to be cleaned comes into contact with the tip of the brush bristles 14b. Thereafter, the brush rotating mechanism 121 causes the brush 14 to rotate in a horizontal plane around the rotation axis 134 as indicated by an arrow A21 in FIG. As a result, the brush bristles 14b rotate along the surface 30a to be cleaned of the workpiece 30, and the foreign matter adhering to the surface 30a to be cleaned is removed. Further, at the time of this pre-cleaning, the shutter 16 whose height position is located at the working position serves as a wall that blocks the intrusion of the cleaning liquid into the positioning means 9 side, and positioning means for the cleaning liquid scattered from the water tank 13 to the outside due to the pre-cleaning. Scattering to the 9 side is prevented.

  When the pre-cleaning is finished, the suction pad 10b is raised, and then moves onto the holding means 6a located at the carry-in / carry-out position to carry the workpiece 30 onto the holding surface 6s. In addition, the suction pad 10b (carrying means 10) again carries the workpiece 30 along the direction indicated by the arrow A22 in FIG. 5-2 in order to carry in the workpiece before the new grinding process after carrying the workpiece 30 into the holding surface 6s. It moves on the positioning means 9 but passes above the shutter 16 at this time. After the pre-cleaning shown in FIG. 5A, the height position of the shutter 16 is lowered to the non-operating position by the shutter drive mechanism 151, as shown in FIG. 5B, so as not to hinder the passage of the suction pad 10b. . Further, when the suction pad 10 b passes above the shutter 16 in this way, the plurality of nozzles 17 arranged on the upper surface of the shutter 16 eject each gas by the gas ejecting mechanism 152. Thereby, gas is injected toward the conveyance surface 101b of the suction pad 10b, and the cleaning liquid adhering to the conveyance surface 101b of the suction pad 10b is removed during the preliminary cleaning.

  Next, workpiece grinding using the grinding apparatus 1 described above will be described. The workpiece before grinding stored in the cassette 7 is taken out by the robot arm 19a of the carry-in / out means 19 and carried out to the positioning means 9, and the center position is positioned. Thereafter, the work surface is sucked and held by the suction pad 10b of the carry-in means 10 and is carried into the pre-cleaning means 12, and the pre-cleaning means is pre-cleaned by the pre-cleaning means.

  The workpiece that has been pre-cleaned by the pre-cleaning means 12 is a surface to be cleaned that is loaded onto the holding means 6a positioned at the loading / unloading position by the suction pad 10b of the loading means 10 and pre-cleaned by the holding surface 6s. The surface of the workpiece is held as a held surface. The holding means 6a at the loading / unloading position holding the work in this way moves to the grinding position by the grinding means 3 along with the rotation of the turntable 5, and the surface to be ground of the work is subjected to grinding by the grinding wheel 3b. At the same time, the work held by the holding means 6b and finished grinding at the grinding position by the grinding means 3 is moved to the grinding position by the grinding means 4, and the surface to be ground of the work is ground by the grinding wheel 4b. To serve. During this time, the next work is carried in and held on the holding means 6c moved to the carry-in / out position by the carry-in means 10.

  Subsequently, the holding means 6a that holds the workpiece that has been ground by the grinding means 3 moves to a grinding position by the grinding means 4 along with the rotation of the turntable 5, and the surface to be ground of the workpiece is ground by the grinding wheel 4b. Provide. At the same time, the next work carried in and held by the holding means 6c moves to a grinding position by the grinding means 3, and the surface to be ground of the work is subjected to grinding by the grinding wheel 3b. In the meantime, the holding means 6b holding the workpiece that has been ground by the grinding means 4 moves to the carry-in / out position.

  Here, the workpiece at the loading / unloading position after finishing the grinding is sucked and held by the suction pad 11 b of the unloading means 11 and is unloaded to the cleaning means 18. The workpiece carried to the cleaning means 18 is gripped by the robot arm 19a of the carry-in / out means 19 after the surface to be ground is washed by the cleaning means 18, and is carried out to the cassette 8 and accommodated in the cassette 8. In addition, after unloading the workpiece after the above-described grinding, the next workpiece is loaded and held by the loading means 10 on the holding means 6b.

  Thereafter, the holding means 6 a holding the workpiece that has been ground by the grinding means 4 moves to the carry-in / carry-out position as the turntable 5 rotates. At the same time, the work held by the holding means 6c and finished at the grinding position by the grinding means 3 is moved to the grinding position by the grinding means 4, and the surface to be ground of the work is ground by the grinding wheel 4b. To serve. Further, the work carried in and held by the holding means 6b moves to a grinding position by the grinding means 3, and the surface to be ground of the work is subjected to grinding by the grinding wheel 3b. The above operation is repeated for each work housed in the cassette 7.

  As described above, according to the present embodiment, the pre-cleaning unit 12 can pre-clean the surface of the workpiece held by the holding units 6a to 6c as the held surface during the grinding process before the grinding process. . At this time, the cleaning liquid scattering preventing means 15 can prevent the cleaning liquid from scattering toward the positioning means 9. Therefore, there is an effect that the surface to be held of the workpiece before grinding can be sufficiently cleaned while preventing the cleaning liquid from splashing around, particularly the positioning means 9 side. Further, when the suction pad 10b (carrying means 10) passes above the cleaning liquid splash prevention means 15 and moves from the pre-cleaning means 12 side to the positioning means 9 side, the suction pad 10b (specifically, the transport surface of the suction pad 10b). 101b) can be sprayed with gas to remove the cleaning liquid adhering to the conveying surface 101b during the pre-cleaning. Accordingly, it is possible to enhance the effect of preventing the cleaning liquid from scattering and entering the positioning means 9 side.

  Further, in the pre-cleaning means 12, the cleaning liquid is supplied from the bottom surface side of the water tank 13 to the internal space of the water tank 13 by the supply port 131 formed on the bottom surface of the water tank 13, and the cleaning liquid of the internal space of the water tank 13 from the bottom surface side of the water tank 13. Therefore, when the cleaning liquid is supplied to the water tank 13 and discharged, the situation where the cleaning water scatters and enters the positioning means 9 side does not occur. Therefore, the effect of preventing the cleaning liquid from scattering and entering the positioning means 9 can be further enhanced.

  As described above, the grinding apparatus of the present invention is suitable for sufficiently cleaning the surface to be held of the workpiece before grinding while preventing the cleaning liquid from being scattered around.

DESCRIPTION OF SYMBOLS 1 Grinding device 3, 4 Grinding means 5 Turntable 6a-6c Holding means 9 Positioning means 10 Carry-in means 10a Transfer arm 10b Suction pad 11 Carry-out means 12 Pre-cleaning means 13 Water tank 14 Brush 121 Brush rotation mechanism 15 Washing liquid scattering prevention means 16 Shutter 17 Nozzle 151 Shutter drive mechanism 152 Gas injection mechanism 18 Cleaning means 19 Carrying in / out means 20 Control means

Claims (2)

A holding means for holding a surface to be held of the work; a grinding means for grinding the work held by the holding means; a positioning means for positioning the work; and holding the work on the transport surface while holding the work. A grinding apparatus comprising a conveying means for conveying between the positioning means and the holding means,
A pre-cleaning unit disposed in the transfer path of the transfer unit and cleaning the held surface of the work before the work is transferred to the holding unit;
Cleaning liquid splash prevention that is disposed between the pre-cleaning means and the positioning means in the middle of the transport path of the transport means and prevents the cleaning liquid from splashing toward the positioning means when cleaning is performed by the pre-cleaning means. Means,
With
The pre-cleaning means is
A water tank in which the cleaning liquid is stored and the work held on the transfer surface of the transfer means is submerged in the cleaning liquid,
A brush disposed in the water tank and in contact with the held surface of the work when the work is submerged in a cleaning liquid in the water tank;
A brush rotation drive mechanism for rotating the brush along the held surface;
Have
The cleaning liquid splash preventing means is
A shutter that blocks splashing of the cleaning liquid;
A shutter drive mechanism for displacing the shutter to an operating position that blocks the scattering of the cleaning liquid and a non-operating position that allows passage of the conveying means;
A nozzle disposed in a position near the passage of the conveying means of the shutter displaced to the non-operating position so that an injection port faces the conveying surface;
A gas injection mechanism for injecting gas from the injection port toward the transfer surface when the transfer unit moves from the pre-cleaning unit side to the positioning unit side after transferring the workpiece to the holding unit; ,
A grinding apparatus comprising:   2. The grinding apparatus according to claim 1, wherein a supply port for supplying the cleaning liquid into the water tank and a discharge port for discharging the cleaning liquid in the water tank to the outside are formed at the bottom of the water tank.

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