JP2013055149A - Grinding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grinding device provided with a chuck table cleaning mechanism for cleaning a holding face of a chuck table without enlarging an entire device.SOLUTION: A chuck table cleaning mechanism 8 comprises: a planarization tool mounted to a rotation shaft vertical to a holding face of a chuck table 4 positioned in a carrying-in and -out region 60e, and planarizing the holding face in contact with the holding face of the chuck table 4; a cleaning water injection nozzle for supplying cleaning water to the holding face of the chuck table 4 positioned in the carrying-in and -out region 60e; cleaning positioning means for moving the planarization tool and the cleaning water injection nozzle in a direction vertical to the holding face of the chuck table 4 and positioning them to a cleaning position and a retreating position; and water droplet receiving means that can be positioned at a water droplet receiving position for receiving water droplets dripping from the planarization tool on a lower side of the planarization tool and a retreating position for allowing movement of the planarization tool to the cleaning position.

Description

  The present invention relates to a grinding apparatus for grinding a workpiece such as a semiconductor wafer or an optical device wafer.

  In the semiconductor device manufacturing process, a large number of rectangular areas are defined by planned cutting lines called streets arranged in a lattice pattern on the surface of a semiconductor wafer having a substantially disk shape, and each of the rectangular areas includes IC, LSI, etc. Form the device. Individual devices are formed by dividing the semiconductor wafer on which a large number of devices are formed in this manner along the streets. In addition, an optical device wafer in which a plurality of regions are partitioned by streets formed in a lattice shape on the surface of a sapphire substrate or the like, and an optical device in which a gallium nitride compound semiconductor or the like is stacked in the partitioned region is, It is divided into optical devices such as individual light-emitting diodes and laser diodes along the planned dividing line, and is widely used in electrical equipment.

  In order to reduce the size and weight of the individually divided devices as described above, the wafer back surface is usually ground and cut in advance before the wafer is cut along the street and divided into individual devices. The thickness is formed. Grinding of the back surface of the wafer includes a chuck table having a holding surface for holding a workpiece, and a chuck table positioning means for positioning the chuck table in the grinding area and a loading / unloading area for loading and unloading the workpiece. doing. In such a grinding apparatus, there is a problem that if the workpiece is held and ground while the grinding scrap is attached to the holding surface of the chuck table, the workpiece is damaged due to the influence of the grinding scrap. In order to solve such problems, the chuck table that holds the workpiece that has been ground in the grinding area is positioned in the loading / unloading area, and the chuck table is held after the ground workpiece is unloaded. A grinding apparatus provided with a chuck table cleaning mechanism for cleaning the surface has been put into practical use. (For example, refer to Patent Document 1.)

JP-A-11-226521

  Thus, the chuck table cleaning mechanism in the grinding apparatus disclosed in Patent Document 1 is positioned in the loading / unloading area to clean the holding surface of the chuck table, and then cleaning water mixed with contaminants is held on the holding surface of the chuck table. It moves horizontally so that it does not drip onto it and is positioned at the retracted position. However, in order to configure the chuck table cleaning mechanism to be movable between the carry-in / carry-out area and the retreat position, a considerable movement space is required, and there is a problem that the entire apparatus is increased in size.

  The present invention has been made in view of the above-described facts, and its main technical problem is to provide a grinding apparatus equipped with a chuck table cleaning mechanism that cleans the holding surface of the chuck table without increasing the size of the entire apparatus. It is in.

In order to solve the above technical problem, according to the present invention, a chuck table having a holding surface for holding a workpiece, and a grinding means for grinding the workpiece disposed in the grinding region and held by the chuck table. A chuck table positioning means for positioning the chuck table in the loading / unloading area for loading and unloading the grinding area and workpiece, and a chuck table cleaning for cleaning a holding surface of the chuck table positioned in the loading / unloading area A grinding device comprising a mechanism,
The chuck table cleaning mechanism is mounted on a rotating shaft perpendicular to the holding surface of the chuck table positioned in the loading / unloading area and is in contact with the holding surface of the chuck table to flatten the holding surface. A cleaning water spray nozzle for supplying cleaning water to the holding surface of the chuck table positioned in the loading / unloading area, the flattening tool and the cleaning water spray nozzle perpendicular to the holding surface of the chuck table. Cleaning positioning means for moving in the direction and positioned at the cleaning position and the retracted position, a water drop receiving position for receiving water droplets dropped from the leveling tool below the leveling tool, and movement of the leveling tool to the cleaning position Water drop receiving means configured to be positioned at a retracted position that allows
A grinding device is provided.

  A flattening tool retracting means for retracting the flattening tool to a position that does not interfere with the cleaning water sprayed from the cleaning water spray nozzle is provided.

In the grinding apparatus according to the present invention, the chuck table cleaning mechanism for cleaning the holding surface of the chuck table positioned in the loading / unloading area has a rotation axis perpendicular to the holding surface of the chuck table positioned in the loading / unloading area. A flattening tool that is mounted and abuts the holding surface of the chuck table to flatten the holding surface, a cleaning water jet nozzle that supplies cleaning water to the holding surface of the chuck table positioned in the loading / unloading area, and a flattening tool And a cleaning positioning means for moving the cleaning water spray nozzle in a direction perpendicular to the holding surface of the chuck table to position it at the cleaning position and the retreat position, and a water droplet that receives water droplets that are dropped from the leveling tool below the leveling tool A water drop receiving means configured to be able to be positioned at a receiving position and a retreat position allowing the movement of the flattening tool to the cleaning position. Therefore, after cleaning the holding surface of the chuck table, the water drop receiving means is positioned on the lower side of the flattening tool at the water drop receiving position for receiving the water drops dripping from the flattening tool, so that contamination adhered to the flattening tool is mixed. Even if the washed water drops, it is received by the water drop receiving means and does not drop on the holding surface of the chuck table.
In addition, the grinding device according to the present invention is configured to be positioned at a water drop receiving position for receiving water droplets dropped from the flattening tool on a lower side of the flattening tool and a retreat position allowing the movement of the flattening tool to the cleaning position. In addition, since the water droplet receiving means is provided, the entire chuck table cleaning mechanism does not need to be configured to be movable between the loading / unloading area and the retracted position, so that the entire apparatus does not increase in size.

1 is a perspective view of a grinding apparatus constructed according to the present invention. Explanatory drawing which shows the relationship between five chuck tables arrange | positioned at the turntable which comprises the grinding apparatus shown in FIG. 1, and four process means. The perspective view of the chuck table washing | cleaning mechanism with which the grinding apparatus shown in FIG. 1 is equipped. Explanatory drawing of the grinding scraping process implemented by the chuck table washing | cleaning mechanism shown in FIG. Explanatory drawing of the grinding | polishing waste washing process implemented by the chuck table washing | cleaning mechanism shown in FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a preferred embodiment of a grinding apparatus configured according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a perspective view of a grinding apparatus constructed in accordance with the present invention.
The grinding apparatus shown in FIG. 1 is provided with an apparatus housing generally indicated by numeral 2. The device housing 2 is formed in a rectangular parallelepiped shape extending elongated. In the work area 21 of the apparatus housing 2 formed in this way, the turntable 3 is rotatably arranged. The turntable 3 is formed in an annular shape having an opening 31 at the center, and is appropriately rotated in the direction indicated by the arrow A by a table rotating means (not shown). The turntable 3 formed in this way is provided with five chuck tables 4a, 4b, 4c, 4d and 4e having a holding surface for holding a workpiece on the upper surface as shown in FIG. Yes. The five chuck tables 4 a, 4 b, 4 c, 4 d, and 4 e are arranged around the opening 31 at the position of the apex of the regular pentagon.

  The support column 5 is erected through the opening 31 of the turntable 3 configured as described above. The support column 5 includes five attachment surfaces 5a, 5b, 5c, 5d, and 5e at the top. Four of the five mounting surfaces (5a, 5b, 5c, 5d) have vertical directions (directions perpendicular to the holding surface which is the upper surface of the chuck tables 4a, 4b, 4c, 4d, and 4e). ) Is provided with a pair of guide rails 51, 51.

  Rough grinding means 6a, intermediate finish grinding means 6b, first finish grinding means 6c, and second finish grinding means 6d are provided on the four mounting surfaces 5a, 5b, 5c, and 5d of the strut 5 thus configured. A pair of guide rails 51 and 51 are arranged so as to be movable. The rough grinding means 6a, the intermediate finish grinding means 6b, the first finish grinding means 6c, and the second finish grinding means 6d include a moving base 61, a spindle housing 62 mounted on the moving base 61, and A rotary spindle 63 rotatably disposed on the spindle housing 62 and a servo motor 64 for driving the rotary spindle 63 to rotate are provided. The lower end portion of the rotary spindle 63 protrudes downward beyond the lower end of the spindle housing 62, and a mounter 65 is provided at the lower end. A grinding wheel 66 is mounted on the lower surface of the mounter 65. The grinding wheel 66 of the rough grinding means 6a is equipped with a rough grinding wheel, and the grinding wheel 66 of the semifinishing grinding means 6b is equipped with a semifinishing grinding wheel, and the first finish grinding means 6c and the second finish grinding wheel. A finishing grinding wheel is mounted on each grinding wheel 66 of the grinding means. The mounting bases 61 of the rough grinding means 6a, intermediate finish grinding means 6b, first finish grinding means 6c, and second finish grinding means 6d constructed in this way are each provided with four attachment surfaces of the above-mentioned column 5. A pair of guided grooves 611 and 611 that are fitted to a pair of guide rails 51 and 51 provided in 5a, 5b, 5c, and 5d, respectively, are formed, and the pair of guided grooves 611 and 611 is paired with a guide. By fitting to the rails 51, 51, the rough grinding means 6a, the intermediate finish grinding means 6b, the first finish grinding means 6c, and the second finish grinding means 6d move along the pair of guide rails 51, 51, respectively. Configured to be possible.

  The grinding apparatus in the illustrated embodiment includes the above rough grinding means 6a, intermediate finish grinding means 6b, first finish grinding means 6c, and second finish grinding means 6d as chuck tables 4a, 4b, 4c, 4d, and 4e, respectively. Four grinding feed means 7a, 7b, 7c, and 7d that are moved in a direction perpendicular to the holding surface that is the upper surface are provided. The four processing feed means 7a, 7b, 7c, and 7d are constituted by a well-known ball screw type moving mechanism. The four processing feed means 7a, 7b, 7c, and 7d are respectively driven by the pulse motor 71 to rotate forward and reverse, thereby moving base 61, that is, rough grinding means 6a, intermediate finish grinding means 6b, and first finish. The grinding means 6c and the second finish grinding means 6d are moved downward (in the direction approaching the holding surface, which is the upper surface of the chuck tables 4a, 4b, 4c, 4d, 4e) and upward (chuck) along the pair of guide rails 51, 51. The table 4a, 4b, 4c, 4d, and 4e are moved in the direction away from the holding surface.

Here, the grinding wheel 66 of the rough grinding means 6a, the intermediate finish grinding means 6b, the first finish grinding means 6c, and the second finish grinding means 6d and the five chuck tables 4a, 4b, 4c, 4d, 4e. The relationship will be described with reference to FIG.
In the state where the five chuck tables 4a, 4b, 4c, 4d, and 4e arranged on the turntable 3 are positioned at the positions shown in FIG. 2, the chuck table 4b is positioned at the grinding wheel 66 of the rough grinding means 6a. The chuck table 4c is positioned in the grinding region 60b where the grinding wheel 66 of the intermediate finish grinding means 6b is located, and the chuck table 4d is ground where the grinding wheel 66 of the first finish grinding means 6c is located. Positioned in the region 60c, the chuck table 4e is positioned in the grinding region 60d where the grinding wheel 66 of the second finish grinding means 6d is located. The surplus chuck table 4a is positioned in a loading / unloading area 60e for loading / unloading the workpiece. The chuck tables 4a, 4b, 4c, 4d, and 4e positioned in this way are positioned so that the center of the chuck table 4b passes through the grinding wheel 66 of the rough grinding means 6a, and the center of the chuck table 4c is intermediate finish grinding. The grinding wheel 66 of the means 6b is positioned to pass, the center of the chuck table 4d is positioned to the position where the grinding wheel 66 of the first finish grinding means 6c passes, and the center of the chuck table 4e is the second finish grinding. The grinding wheel 66 of the means 6d is located at a position where it passes. Thus, the turntable 3 on which the five chuck tables 4a, 4b, 4c, 4d, and 4e are arranged and the table rotating means (not shown) that appropriately rotates the turntable 3 in the direction indicated by the arrow A are the chuck table. It functions as a chuck table positioning means for positioning 4a, 4b, 4c, 4d, 4e in the grinding areas 60a, 60b, 60c, 60d and the carry-in / out area 60e.

The grinding device configured as described above erected the support column 5 through the opening 31 of the turntable 3 in which the five chuck tables 4a, 4b, 4c, 4d, and 4e are disposed. Since the four rough grinding means 6a, the intermediate finish grinding means 6b, the first finish grinding means 6c, and the second finish grinding means 6d are attached to the four processing means, the entire apparatus is reduced in size and has a large installation area. Therefore, the equipment cost can be suppressed.
Further, the grinding apparatus in the illustrated embodiment has rough grinding means 6a, intermediate finish grinding means 6b, first finish grinding means 6c, first finish grinding means 6c attached to the four attachment surfaces 5a, 5b, 5c and 5d of the column 5. As shown in FIG. 2, the finish grinding means 6 d of 2 is arranged symmetrically with respect to a line S connecting the workpiece loading / unloading region 60 e and the center of the column 5 as a symmetry axis. The balance of rigidity is good and the processing accuracy is improved. In addition, the right and left parts can be shared, and the number of parts can be reduced.

  The grinding apparatus in the illustrated embodiment includes a chuck table cleaning mechanism 8 that cleans the holding surface of the chuck table positioned in the loading / unloading area 60e. The chuck table cleaning mechanism 8 will be described with reference to FIGS. The chuck table cleaning mechanism 8 in the illustrated embodiment is mounted on a mounting surface 5e facing the loading / unloading region 60e in the support column 5. The chuck table cleaning mechanism 8 is capable of moving in a direction (vertical direction) perpendicular to the holding surface of the chuck table on the support substrate 81 attached to the attachment surface 5e of the support column 5 by appropriate fixing means. A movable substrate 82 disposed on the movable substrate 82, a tool housing 83 disposed on the movable substrate 82 so as to be movable in a direction (vertical direction) perpendicular to the holding surface of the chuck table, and the tool housing 83 A rotating shaft 84 that is arranged to be rotatable in a direction (vertical direction) perpendicular to the holding surface of the chuck table, a flattening tool 85 mounted on the lower end of the rotating shaft 84, and a loading / unloading area 60e. A cleaning water jet nozzle 86 is provided for supplying cleaning water to the holding surface of the positioned chuck table.

  A pair of guide rails 811 and 811 are provided on the front surface of the support substrate 81 constituting the chuck table cleaning mechanism 8 in a direction (vertical direction) perpendicular to the holding surface of the chuck table. On the other hand, the movable substrate 82 is provided with a pair of guided grooves 821 and 821 that fits with the pair of guide rails 811 and 811, and the pair of guided grooves 821 and 821 is connected to the pair of guide rails 811 and 811. The movable board 82 is supported so as to be movable along the pair of guide rails 811 and 811. As described above, the guide rail 822 is provided on the front surface of the movable substrate 82 supported so as to be movable along the pair of guide rails 811 and 811. The tool housing 83 is provided with a guided groove 831 that fits with the guide rail 822, and the tool housing 83 moves along the guide rail 822 by fitting the guided groove 831 with the guide rail 822. Supported as possible. A rotary shaft 84 rotatably disposed in the tool housing 83 is driven to rotate by a servo motor 840. The flattening tool 85 attached to the lower end of the rotating shaft 84 is an oil stone or the like. The cleaning water spray nozzle 86 is mounted on the moving substrate 82 and connected to a cleaning water supply means (not shown). The washing water injection nozzle 86 is a so-called two-fluid nozzle, is supplied with pure water of about 0.2 MPa, is supplied with air of about 0.3 to 0.5 MPa, and the pure water is supplied with air pressure. The holding surface of the chuck table is cleaned by jetting.

  The chuck table cleaning mechanism 8 in the illustrated embodiment includes cleaning positioning means 87 that moves the moving substrate 82 along a pair of guide rails 811 and 811 provided on the support substrate 81. The cleaning positioning means 87 includes a male screw rod 871 disposed on the front side of the support substrate 81 and extending in the vertical direction, and a pulse motor 872 that rotationally drives the male screw rod 871, and the male screw rod 871 is provided on the moving substrate 82. It is screwed into a through female screw hole 823 extending in the vertical direction. Therefore, when the pulse motor 871 is rotated forward or reversely, the moving base 82 is moved upward or downward along the pair of guide rails 811 and 811. The cleaning positioning means 87 configured in this way includes a cleaning position where the flattening tool 85 mounted on the rotary shaft 84 disposed in the tool housing 83 abuts against the holding surface of the chuck table, and flattening from the cleaning position. The tool 85 is positioned at a retreat position where the tool 85 is retreated upward.

  Further, the chuck table cleaning mechanism 8 in the illustrated embodiment includes a flattening tool retracting means 88 that moves the tool housing 83 along a guide rail 822 provided on the moving substrate 82. The flattening tool retracting means 88 is composed of an air cylinder mechanism, and by retracting the tool housing 83 by a predetermined amount along the guide rail 822, the flattening tool retracting means 88 is retracted to a position that does not interfere with the cleaning water sprayed from the cleaning water spray nozzle 86. Let

  The chuck table cleaning mechanism 8 in the illustrated embodiment has a water drop receiving position for receiving water droplets dropped from the flattening tool 85 on the lower side of the flattening tool 85 and a retracted position that allows the flattening tool 85 to move to the cleaning position. A water droplet receiving means 89 configured to be positioned is provided. The water droplet receiving means 89 includes a pair of support levers 891 and 891 whose upper ends are swingably supported on both sides of the support substrate 81, and a water droplet receiving plate 892 connected to the pair of support levers 891 and 891. The water drop receiving plate 892 is placed at a water drop receiving position (see FIG. 3) located below the flattening tool 85 and a retracted position (see FIGS. 4 and 5) that allows the flattening tool 85 to move to the cleaning position. The actuator 893 is an air cylinder for positioning.

  Returning to FIG. 1, the description will be continued. At the front end portion (the lower left end portion in FIG. 1) of the work area 21 of the apparatus housing 2, the first cassette 11, the second cassette 12, the centering means 13, A spinner cleaning means 14, a workpiece conveying means 15, a workpiece carrying-in means 16 and a workpiece carrying-out means 17 are disposed. The first cassette 11 accommodates a wafer 10 such as an optical device wafer or a semiconductor wafer as a workpiece before processing, and is placed in a cassette carry-in area of the apparatus housing 2. In addition, the wafer 10 accommodated in the 1st cassette 11 is accommodated with the back surface up in the state which stuck the protective tape T on the surface. The second cassette 12 is placed in the cassette unloading area of the apparatus housing 2 and stores the processed wafer 10. The centering means 13 is disposed between the first cassette 11 and the workpiece loading / unloading area 60e, and performs centering of the wafer 10 before processing. The spinner cleaning means 14 is disposed between the workpiece loading / unloading area 60e and the second cassette 12, and cleans the processed wafer 10. The workpiece conveying means 15 is disposed between the first cassette 11 and the second cassette 12, and the wafer 10 as a workpiece stored in the first cassette 11 is carried out to the centering means 13. At the same time, the wafer 10 cleaned by the spinner cleaning means 14 is transported to the second cassette 12.

  The workpiece carrying-in means 16 is disposed between the centering means 13 and the work-in / out area 60e, and the unprocessed wafer 10 placed on the centering means 13 is placed on the workpiece. It is conveyed onto the chuck table 4 (4a, 4b, 4c, 4d, 4e) positioned in the carry-in / carry-out area 60e. The workpiece unloading means 17 is disposed between the workpiece loading / unloading area 60e and the spinner cleaning means 14, and is positioned in the loading / unloading area 60e. The chuck table 4 (4a, 4b, 4c, 4d) is disposed. 4e) The processed wafer 10 placed on the substrate 10 is conveyed to the cleaning means 14.

  The first cassette 11 containing a predetermined number of wafers 10 before processing is placed in a predetermined cassette carry-in area of the apparatus housing 2. When all the unprocessed wafers 10 stored in the first cassette 11 placed in the cassette carry-in area are unloaded, a predetermined number of wafers 10 before the processing are replaced with a predetermined number of wafers 10. The accommodated new cassette 11 is manually placed in the cassette carry-in area. On the other hand, when a predetermined number of processed wafers 10 are loaded into the second cassette 12 placed in a predetermined cassette unloading area of the apparatus housing 2, the second cassette 12 is manually unloaded and a new empty The second cassette 12 is placed.

The grinding apparatus in the illustrated embodiment is configured as described above, and the operation thereof will be described mainly with reference to FIG.
The wafer 10, which is a workpiece before processing, accommodated in the first cassette 11 is conveyed by the vertical movement and forward / backward movement of the workpiece conveying means 15, placed on the centering means 13, and has six pins. Centered by radial motion toward the center. If the wafer 10 is centered in the centering means 13, the workpiece carrying-in means 16 is operated to suck and hold the wafer 10 centered in the centering means 13, and the work-in / out area 60e. Is conveyed onto the chuck table 4a positioned at the position. At this time, the water droplet receiving plate 892 constituting the water droplet receiving means 89 of the chuck table cleaning mechanism 8 is positioned at the water droplet receiving position shown in FIG. The wafer 10 thus transported onto the chuck table 4a is sucked and held on the chuck table 4a by operating a suction means (not shown). Next, the turntable 3 is rotated by a predetermined amount in a direction indicated by an arrow A by a rotation drive mechanism (not shown), and the chuck table 4a that sucks and holds the wafer 10 is ground on a grinding region 60a where the grinding wheel 66 of the rough grinding means 6a is located. Position. The turntable 3 rotates to position the chuck table 4b in the grinding region 60b where the grinding wheel 66 of the intermediate finish grinding means 6b is located, and the chuck table 4c serves as the grinding wheel 66 of the first finish grinding means 6c. The chuck table 4d is positioned in the grinding area 60c, the chuck table 4d is positioned in the grinding area 60d in which the grinding wheel 66 of the second finish grinding means 6d is positioned, and the chuck table 4e carries in / out the workpiece. 60e.

  Rough grinding is performed by the rough grinding means 6a on the back surface (upper surface) of the wafer 10 held by the chuck table 4a positioned in the grinding region 60a where the grinding wheel 66 of the rough grinding means 6a is located. During this time, the unprocessed wafer 10 is placed on the chuck table 4e, which is positioned in the loading / unloading area 60e for loading / unloading the workpiece. The wafer 10 placed on the chuck table 4e is sucked and held on the chuck table 4e by operating a suction means (not shown).

  Next, the turntable 3 is rotated by a predetermined amount in the direction indicated by the arrow A by a rotation driving mechanism (not shown). As a result, the chuck table 4e that sucks and holds the unprocessed wafer 10 in the loading / unloading area 60e is positioned in the grinding area 60a where the grinding wheel 66 of the rough grinding means 6a is positioned, and rough grinding is performed as described above. The chuck table 4a that sucks and holds the wafer 10 is positioned in the grinding region 60b where the grinding wheel 66 of the intermediate finish grinding means 6b is located, and the chuck table 4b is the grinding region where the grinding wheel 66 of the first finish grinding means 6c is located. The chuck table 4c is positioned in the grinding region 60d where the grinding wheel 66 of the second finish grinding means 6d is positioned, and the chuck table 4d is positioned in the loading / unloading region 60e for loading / unloading the workpiece. .

  In this way, the turntable 3 is sequentially rotated in the direction indicated by the arrow A, and the chuck table 4a holding and holding the wafer 10 subjected to the second finish grinding process carries in / out the workpiece. Positioned in region 60e.

  As described above, the grinding region 60a where the grinding wheel 66 of the rough grinding means 6a is located, the grinding region 60b where the grinding wheel 66 of the intermediate finish grinding means 6b is located, and the grinding wheel 66 of the first finish grinding means 6c are located. The chuck table 4a that has returned to the workpiece loading / unloading zone 60e via the grinding zone 60d and the grinding zone 60d where the grinding wheel 66 of the second finish grinding means 6d is located is subjected to the second finish grinding. Release the suction hold of the wafer. Next, the workpiece carry-out means 17 is operated, and the wafer 10 after the second finish grinding is placed on the chuck table 4a positioned in the loading / unloading region 60e for loading / unloading the workpiece. Is conveyed to the spinner cleaning means 14. The wafer 10 transported to the cleaning means 14 is cleaned here and then stored in a predetermined position of the second cassette 12 by the workpiece transport means 15.

  As described above, when the wafer 10 after the second finish grinding held on the chuck table 4a positioned in the loading / unloading area 60e is transferred to the spinner cleaning means 14, the holding surface of the chuck table 4a is cleaned. Perform the chuck table cleaning process. In order to carry out this chuck table cleaning step, first, the actuator 893 constituting the water droplet receiving means 89 of the chuck table cleaning mechanism 8 is actuated, and the water droplet receiving plate 892 is moved to the flattening tool as shown in FIGS. 85 is positioned at a retreat position that allows movement to the cleaning position. Next, as shown in FIG. 4, the chuck table 4 a is rotated in the direction indicated by the arrow B, and the cleaning positioning means 87 is operated to move the moving substrate 82 along a pair of guide rails 811 and 811 provided on the support substrate 81. The flattening tool 85 mounted on the rotary shaft 84 disposed in the tool housing 83 is positioned at a cleaning position where it abuts against the holding surface of the chuck table, and the servomotor 840 is operated to cause the flattening tool 85 to move. Rotate in the direction indicated by arrow C. At this time, the flattening tool 85 is positioned so as to pass through the center of the chuck table 4a. As a result, the grinding waste generated in each grinding step described above and adhering to the holding surface of the chuck table 4a is scraped, and the holding surface is formed into a flat surface (grinding scraping step). When performing the grinding scraping process, cleaning water composed of pure water and air may be sprayed from the cleaning water spray nozzle 86. When the grinding scraping process is performed in this manner, the flattening tool retracting means 88 is operated to raise the tool housing 83 along the guide rail 822 by a predetermined amount as shown in FIG. The tool 85 is retracted to a position that does not interfere with the cleaning water sprayed from the cleaning water spray nozzle 86. Then, cleaning water composed of pure water and air is sprayed from the cleaning water jet nozzle 86 onto the holding surface of the chuck table 4a to wash away the grinding scraps removed in the grinding scrap cutting step (grind scrap washing step).

  When the chuck table cleaning process is performed as described above, the movable base 82 is raised and positioned at the retracted position, and then the actuator 893 that constitutes the water droplet receiving means 89 is operated, and the water droplet receiving plate 892 is shown in FIG. As shown in FIG. 3, it is positioned at a water droplet receiving position located below the flattening tool 85. Therefore, even if the cleaning water mixed with contamination adhering to the flattening tool 85 is dropped, it is not received by the water drop receiving plate 892 and dropped on the holding surface of the chuck table 4a. In this way, after the chuck table cleaning process is performed on the holding surface of the chuck table 4a positioned in the loading / unloading area 60e, the water droplet receiving plate 892 is positioned below the flattening tool 85 as shown in FIG. When positioned at the water droplet receiving position, the unprocessed wafer 10 is placed on the holding surface of the chuck table 4a.

2: Device housing 3: Turntable 4a, 4b, 4c, 4d, 4e: Chuck table 5: Support columns 5a, 5b, 5c, 5d, 5e: Mounting surface 6a: Coarse grinding means 6b: Medium finish grinding means 6c: First Finish grinding means 6d: second finish grinding means 62: spindle housing 63: rotating spindle 66: grinding wheels 7a, 7b, 7c, 7d: processing feeding means 8: chuck table cleaning mechanism 81: support substrate 82: moving substrate 83 : Tool housing 84: Rotating shaft 85: Flattening tool 86: Washing water injection nozzle 87: Cleaning positioning means 88: Flattening tool retracting means 89: Water drop receiving means 10: Wafer 11: First cassette 12: Second cassette 13: Centering means 14: Spinner cleaning means 15: Workpiece conveying means 16: Workpiece carrying means 17: Addition Work removal means

Claims (2)

A chuck table having a holding surface for holding a workpiece, a grinding means disposed in a grinding area for grinding the workpiece held on the chuck table, and carrying the chuck table into the grinding area and the workpiece And a chuck table positioning means for positioning in a loading / unloading area to be unloaded and a chuck table cleaning mechanism for cleaning a holding surface of the chuck table positioned in the loading / unloading area,
The chuck table cleaning mechanism is mounted on a rotating shaft perpendicular to the holding surface of the chuck table positioned in the loading / unloading area and is in contact with the holding surface of the chuck table to flatten the holding surface. A cleaning water spray nozzle for supplying cleaning water to the holding surface of the chuck table positioned in the loading / unloading area, the flattening tool and the cleaning water spray nozzle perpendicular to the holding surface of the chuck table. Cleaning positioning means for moving in the direction and positioned at the cleaning position and the retracted position, a water drop receiving position for receiving water droplets dropped from the leveling tool below the leveling tool, and movement of the leveling tool to the cleaning position Water drop receiving means configured to be positioned at a retracted position that allows
A grinding apparatus characterized by that.   The grinding apparatus according to claim 1, further comprising a planarizing tool retracting unit configured to retract the planarizing tool to a position that does not interfere with the cleaning water sprayed from the cleaning water spray nozzle.

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