JP7841860B2 - processing equipment - Google Patents

Description

This invention relates to a processing apparatus having a function for cleaning the holding surface of a porous member by spraying it with two fluids.

A grinding apparatus that holds and grinds wafers using a chuck table with a porous material as the holding surface is equipped with a nozzle that sprays two fluids, and the holding surface is cleaned by the two fluids sprayed from the nozzle (see, for example, Patent Documents 1 and 2).

Japanese Patent Publication No. 2011-200785 Japanese Patent Publication No. 2020-119931

The holding surface of a porous member has irregularities. Therefore, the two fluids sprayed from the nozzle are scattered on the holding surface due to these irregularities. That is, the two fluids that hit the holding surface not only flow in the direction of the surface (forward of the spray direction), but also scatter in the opposite direction. This scattering of the two fluids on the holding surface can cause machining debris to re-adhere to the surface.

Therefore, in a processing apparatus equipped with a function to clean the holding surface of a porous member by spraying two fluids from a nozzle, there is a challenge in preventing the two fluids from scattering on the holding surface.

The present invention relates to a processing apparatus comprising a chuck table for suction-holding a workpiece on a holding surface having irregularities of a porous member, and a processing unit for grinding or polishing the workpiece held by the holding surface, wherein the processing apparatus comprises a cleaning unit having a nozzle for spraying a two-fluid mixture of water and air in a spraying direction inclined with respect to the holding surface, the cleaning unit comprising a scattering prevention unit for preventing the scattering of the two-fluid mixture sprayed from the nozzle at least to the sides and rear in the spraying direction due to the irregularities of the holding surface, the scattering prevention unit comprising a front plate having a lower surface facing the holding surface and positioned on the front side in the spraying direction of the two-fluid mixture, the front plate preventing diffuse reflection of the two-fluid mixture by causing the two-fluid mixture to descend after being guided forward and hitting the front plate , a rear plate positioned on the opposite side of the front plate with the nozzle in between, a pair of side plates connected to both sides of the rear plate and surrounding the nozzle together with the rear plate, and flat plates connected to the lower ends of each of the side plates and extending in a direction parallel to the holding surface and away from each other.
The scattering prevention unit further includes a parallel plate provided at the lower end of the rear plate, parallel to the reduced diameter portion at the lower end of the nozzle, such that a gap is formed between the parallel plate and the reduced diameter portion. The gap between the tip of the parallel plate and the tip of the reduced diameter portion of the nozzle becomes a negative pressure when the two fluids are ejected from the injection portion provided at the lower end of the reduced diameter portion, functioning as an outside air introduction portion that introduces outside air from the rear side of the rear plate. The parallel plate also functions as a guide that ejects the introduced outside air toward the injection portion side of the nozzle, and it is desirable that the introduced outside air prevents the scattering of the two fluids backward in the injection direction due to the unevenness of the holding surface.

In this invention, the cleaning unit is equipped with a scattering prevention unit that prevents the scattering of the two fluids due to irregularities on the holding surface of the chuck table, thereby reducing the risk of processing debris re-adhering to the holding surface.
Furthermore, by providing an outside air intake section that guides outside air in the direction of injection using the two fluids ejected by the nozzle, the risk of scattering of the two fluids can be further reduced.

This is a perspective view showing an example of a processing apparatus. This is a front view showing an example of a washing unit and a chuck table. This is a cross-sectional view showing the state in which two fluids are being injected from the nozzle toward the holding surface of the chuck table. This is a perspective view showing an example of a gas-liquid separation unit. This is a perspective view showing the state in which two fluids are being injected from a rotating nozzle toward the holding surface of the chuck table.

1. Configuration of the Processing Device The processing device 1 shown in Figure 1 is a processing device that processes a workpiece 100 held on a chuck table 5 using processing units consisting of a rough grinding unit 30, a finish grinding unit 31, and a polishing unit 32. The processing device 1 is equipped with a control unit 17, which controls various mechanisms when transporting the workpiece 100, grinding, polishing, etc.

The processing apparatus 1 is configured with a second apparatus base 11 connected to the rear (+Y direction) of a first apparatus base 10. The first apparatus base 10 serves as an loading/unloading area 91 where the workpiece 100 is loaded and unloaded. The second apparatus base 11 serves as a processing area 92 where the workpiece 100, held on the chuck table 5 by a rough grinding unit 30, a finish grinding unit 31, or a polishing unit 32, is processed.

The front side (-Y direction side) of the first device base 10 is provided with a first cassette mounting section 150 and a second cassette mounting section 151. The first cassette mounting section 150 holds a first cassette 173 containing the workpiece 100 before processing, while the second cassette mounting section 151 holds a second cassette 174 containing the workpiece 100 after processing.

An opening (not shown) is provided at the rear (+Y direction) of the first cassette 173. Behind this opening, a robot 155 is positioned to unload the workpiece 100 from the first cassette 173 and load the processed workpiece 100 into the second cassette 174. Adjacent to the robot 155 is a temporary storage area 152, which includes a rotatable table 153 and a camera 154 for imaging the upper surface 101 of the workpiece 100 placed on the table 153.

A first transport mechanism 171 is positioned adjacent to the temporary storage area 152, which rotates while holding the workpiece 100. The first transport mechanism 171 can hold the workpiece 100 located in the temporary storage area 152 and transport it to one of the chuck tables 5 located within the processing area 92. Next to the first transport mechanism 171, a second transport mechanism 172 is provided, which rotates while holding the processed workpiece 100. Near the second transport mechanism 172, a spinner cleaning unit 156 is positioned to clean the processed workpiece 100 transported by the second transport mechanism 172. The workpiece 100 cleaned by the spinner cleaning unit 156 is then transported to a second cassette 174 by a robot 155.

A first column 12 is erected on the front -X side of the second device base 11, and a rough grinding feed unit 20 is arranged on the side of the first column 12. The rough grinding feed unit 20 includes a ball screw 200 having an axis in the vertical direction (Z-axis direction), a pair of guide rails 201 arranged parallel to the ball screw 200, a motor 202 connected to the ball screw 200 to rotate the ball screw 200, a lifting plate 203 whose internal nut is screwed onto the ball screw 200 and whose side slides against the guide rail 201, and a holder 204 connected to the lifting plate 203 to hold the rough grinding unit 30. When the motor 202 rotates the ball screw 200, the lifting plate 203 is guided by the guide rail 201 and reciprocates in the Z-axis direction. The rough grinding unit 30, supported by the holder 204 connected to the lifting plate 203, also reciprocates in the Z-axis direction.

The rough grinding unit 30 comprises a rotating shaft 300 whose axial direction is vertical (Z-axis direction), a housing 301 that rotatably supports the rotating shaft 300, a motor 302 that rotationally drives the rotating shaft 300, a mount 303 connected to the lower end of the rotating shaft 300, and a grinding wheel 304 detachably connected to the lower surface of the mount 303. The grinding wheel 304 comprises a wheel base 305 and a plurality of roughly rectangular parallelepiped-shaped rough grinding wheels 306 arranged in an annular pattern on the bottom surface of the wheel base 305.

Furthermore, a second column 13 is erected on the rear -X side of the second device base 11, and a finish grinding feed unit 21 is positioned in front of the second column 13. The finish grinding feed unit 21 is configured similarly to the rough grinding feed unit 20 and can feed the finish grinding unit 31 in the Z-axis direction. The finish grinding unit 31 includes a finish grinding wheel 307 in which the abrasive grains contained are smaller than those of the rough grinding wheel 306, and its other configurations are the same as those of the rough grinding unit 30. Each part of the finish grinding feed unit 21 is denoted by the same reference numerals as the rough grinding feed unit 20, and its description is omitted. Similarly, for the finish grinding unit 31, each part other than the finish grinding wheel 307 is denoted by the same reference numerals as the rough grinding unit 30, and its description is omitted.

On the rear +X side of the second device base 11, a third column 14 is erected alongside the second column 13 in the X-axis direction. An X-axis movement unit 24 is positioned on the front of the third column 14. The X-axis movement unit 24 consists of a ball screw 240 having an axis in the X-axis direction, a pair of guide rails 241 arranged parallel to the ball screw 240, a motor 242 for rotating the ball screw 240, and a movable plate 243 whose internal nut is screwed onto the ball screw 240 and whose side slides against the guide rails 241. When the motor 242 rotates the ball screw 240, the movable plate 243 is guided by the guide rails 241 and moves in the X-axis direction. The polishing unit 32, positioned on the movable plate 243, moves in the X-axis direction as the movable plate 243 moves.

A polishing feed unit 25 is provided on the front of the movable plate 243 to raise and lower the polishing unit 32 in the Z-axis direction, moving it closer to or further away from the chuck table 5. The polishing feed unit 25 consists of a ball screw 250 having a vertical axis, a pair of guide rails 251 arranged parallel to the ball screw 250, a motor 252 connected to the ball screw 250 to rotate it, a lifting plate 253 with an internal nut screwed onto the ball screw 250 and its side sliding against the guide rails 251, and a holder 254 connected to the lifting plate 253 to hold the polishing unit 32. When the motor 252 rotates the ball screw 250, the lifting plate 253 is guided by the guide rails 251 and moves in the Z-axis direction, and the polishing unit 32 supported by the holder 254 also moves in the Z-axis direction.

The polishing unit 32 consists of a spindle 320 whose axial direction is the Z-axis direction, a housing 321 that rotatably supports the spindle 320, a motor 322 that rotationally drives the spindle 320, a mount 323 fixed to the lower end of the spindle 320, and a circular polishing pad 324 detachably attached to the lower surface of the mount 323. The polishing pad 324 is made of a nonwoven fabric such as felt, and has a through-hole (not shown) in its central portion through which slurry (polishing liquid containing free abrasive particles) passes. The diameter of the polishing pad 324 is larger than the diameter of the chuck table 5.

As shown in Figure 1, a turntable 6 is mounted on the second device base 11, and four chuck tables 5 are arranged on the upper surface of the turntable 6 at equal intervals in the circumferential direction. A rotation axis (not shown) is mounted at the center of the turntable 6 for rotating it, allowing the turntable 6 to rotate around the axis in the Z-axis direction. The rotation of the turntable 6 causes the four chuck tables 5 to revolve, allowing the chuck tables 5 to be sequentially positioned below the rough grinding unit 30, below the finish grinding unit 31, and below the polishing unit 32.

The adjacent chuck tables 5 are separated by a partition plate 161. The individual areas separated by the partition plate 161 are the loading/unloading area 181 where the workpiece 100 is loaded and unloaded, the rough grinding area 182 where rough grinding takes place, the finish grinding area 183 where finish grinding takes place, and the polishing area 184 where polishing takes place.

The spinner cleaning unit 156 includes a spinner table 157 that holds and rotates the workpiece, and a nozzle 158 that sprays cleaning fluid onto the workpiece. Instead of cleaning fluid, a two-fluid mixture of water and air may be used.

A cleaning unit 7, as shown in Figure 2, is installed in the loading/unloading area 181. As shown in Figure 2, the cleaning unit 7 includes a nozzle unit 72 for spraying two fluids, an arm 73 to which the nozzle unit 72 is fixed, a swivel motor 71 for rotating the arm 73, and a lifting actuator 74 for raising and lowering the swivel motor 71, the arm 73, and the nozzle unit 72. An air source 75 and a water source 76 are connected to the nozzle unit 72, allowing it to spray a mixture of air supplied from the air source 75 and water supplied from the water source 76.

The chuck table 5 comprises a porous member 50 for suction and holding a workpiece, a frame 51 that supports the porous member 50 from below and the side, and a support base 52 that supports the frame 51. The upper surface of the porous member 50 is a holding surface 500 for suction and holding a workpiece, and the holding surface 500 has irregularities. A shaft portion 53 is connected to the support base 52. A flow path 54 through which water or air flows is formed inside the frame 51, the support base 52, and the shaft portion 53. One end of the flow path 54 is open at multiple locations on the upper surface of the frame 51. The other end of the flow path 54 can be selectively connected to a suction source 557, an air source 558, and a water source 559 via three flow rate adjustment valves 551, 552, and 553 and three on/off valves 554, 555, and 556. When valve 554 is open and valves 555 and 556 are closed, the porous member 50 and the suction source 557 are in communication, allowing a suction force to be applied to the holding surface 500. When valve 555 is open and valves 554 and 556 are closed, the porous member 50 and the air source 558 are in communication, allowing air to be ejected from the holding surface 500. When valve 556 is open and valves 554 and 555 are closed, the porous member 50 and the water source 559 are in communication, allowing water to be ejected from the holding surface 500. Furthermore, when valves 555 and 556 are open and valve 554 is closed, the porous member 50 and the air source 558 and water source 559 are in communication, allowing a mixture of air and water to be ejected from the holding surface 500.

A bracket 61 is fixed to the underside of the turntable 6, and the bracket 61 holds the motor 56 that rotates the chuck table 5. A drive pulley 562 is disposed at the upper end of the motor 56's shaft 561. On the other hand, a driven pulley 563 is disposed on the shaft 53 of the chuck table 5. A belt 564 is wound around the drive pulley 562 and the driven pulley 563. When the motor 56 rotates the shaft 561, the rotational force is transmitted to the shaft 53 by the belt 564, causing the chuck table 5 to rotate. The support base 52 is rotatably supported by a bearing 62 fixed to the turntable 6.

As shown in Figure 3, the nozzle unit 72 is equipped with a nozzle 77 that injects two fluids onto the holding surface 500. The nozzle 77 comprises a cylindrical body 771, an air inlet 772 formed on the side of the cylindrical body 771 and communicating with an air source 75, a water inlet 773 formed on the side of the cylindrical body 771 and communicating with a water source 76, a reduced-diameter section 774 at the lower end of the cylindrical body 771, an injection section 775 opening at the lower end of the reduced-diameter section 774, an air passage 776 communicating with the air inlet 772, and a water passage 777 communicating with the water inlet 773. The air passage 776 and the water passage 777 merge inside the reduced-diameter section 774 to generate two fluids 778, which are then ejected from the injection section 775.

The injection direction of the two fluids 778 is inclined with respect to the holding surface 500 of the chuck table 5. A rear plate 781 is positioned behind the nozzle 77 in the injection direction, parallel to the injection direction of the two fluids and at an acute angle with respect to the holding surface 500. The lower end of this rear plate 781 is bent toward the injection section 775 and is provided with a parallel plate 782 formed substantially parallel to the reduced diameter section 774. A gap is formed between the parallel plate 782 and the reduced diameter section 774. The rear plate 781 and the parallel plate 782 may be in contact with the nozzle 77.
Furthermore, the lower end of the side plate 784 may be provided with a flat plate 787 that extends parallel to the holding surface 500 and away from the nozzle 77.

Two side plates 784 are connected to both the left and right ends of the rear plate 781 (the front and back sides in the diagram of Figure 3). The two side plates 784 are positioned opposite each other, flanking the nozzle 77, and the rear plate 781 and the two side plates 784 surround the nozzle 77. Note that the rear plate 781 and the side plates 784 may be formed as a single unit.

A front plate 785 is positioned at the front of the reduced-diameter section 774 in the direction of the ejection of the two fluids. The front plate 785 is a plate-shaped member facing the holding surface 500, and its surface direction is preferably between an angle perpendicular to the ejection direction of the two fluids 778 and an angle parallel to the holding surface 500.

When air flowing in from the air inlet 772 and water flowing in from the water inlet 773 merge inside the reduced diameter section 774 to generate two fluids 778, which are then ejected from the injection section 775, the processing debris adhering to the holding surface 500 is scraped off and rises due to the two fluids. However, the rising processing debris collides with the front plate 785, thus preventing the mist containing the processing debris from scattering.
Furthermore, when the two fluids 778 are ejected from the injection section 775, a negative pressure is created in the gap 783 between the tip of the reduced-diameter section 774 of the nozzle 22 and the tip of the parallel plate 782, and outside air 788 is introduced from the rear side of the rear plate 781. In other words, the gap 783 functions as an outside air introduction section. The tip of the reduced-diameter section 774 and the tip of the parallel plate 782 may be in contact. When outside air is introduced from the rear side of the rear plate 781, the outside air is guided by the parallel plate 782 and ejected forward (towards the injection section 775). Therefore, it is possible to prevent the two fluids 778 and the mist of the two fluids reflected by the holding surface 500 from flowing backward, and thus it is possible to prevent processing chips from scattering backward.
In this way, the scattering of the two fluids is prevented because the two fluids 778 and the reflected two fluids flow only forward. Therefore, the scattering prevention section 786 is formed by the front plate 785, the rear plate 781 and the side plate 784.

A gas-liquid separation unit 70 is installed on the side of the loading/unloading area 181 near the boundary between the loading/unloading area 181 and the polishing area 184, as shown in Figure 1. Alternatively, the gas-liquid separation unit 70 may be installed on the side of the loading/unloading area 181 near the boundary between the loading/unloading area 181 and the rough grinding area 182.

As shown in Figure 4, the gas-liquid separation unit 70 is equipped with a top plate 700, a plurality of side plates 701 hanging down from the top plate 700, and an inlet 702 for receiving scattered mist. The top plate 700 is shaped so as not to overlap the chuck table 5 when the chuck table 5 holding the workpiece 100 is positioned in the loading/unloading area 181, as viewed from the +Z side. It is also shaped to effectively guide the two fluids 778 sprayed from the nozzle 77 and scattered during the cleaning of the workpiece 100 to the gas-liquid separation unit 70 for gas-liquid separation. In this embodiment, the top plate 700 is formed to be elongated in the X-axis direction toward the rotation center of the turntable 6.

The top plate 700 is formed in a roughly rectangular shape with a portion (located above the chuck table 5) cut out. This cut-out portion comprises a first side 705 parallel to the X-axis direction and a hypotenuse 706, one end of which is connected to the +X end of the first side 705 and which is angled with respect to the X-axis direction. The top plate 700 also comprises a second side 707 connected to the other end of the hypotenuse 706 and parallel to the X-axis direction, and opposing third and fourth sides 708 and 709 parallel to the Y-axis direction. However, the shape of the top plate 700 is not limited to this. For example, instead of the first side 705 and the hypotenuse 706, it may have a portion formed in an arc shape along the periphery of the chuck table 5.

The side plate 701 is composed of a first side plate 710 formed on the +Y direction side, i.e., the upstream side in the orbital direction of the chuck table 5; a second side plate 711 formed on the +X direction side, i.e., the outer circumference side of the orbital trajectory of the chuck table 5, and the side furthest from the center of rotation of the chuck table 5; and a third side plate 712 formed on the side in the direction between the +X direction and the -Y direction, refracted from the second side plate 711 and aligned with the outer circumference of the orbital trajectory of the chuck table 5. The first side plate 710 is fixed to the side of the partition plate 161, for example, and the lower parts of the second side plate 711 and the third side plate 712 are fixed to the first device base 10, for example. In other words, the side plate 701 is arranged in the direction in which the mist is scattered and has the role of receiving the scattered mist. On the other hand, in the gas-liquid separation unit 70, there are no side plates on the -Y side, i.e., the side closer to where the two fluids 778 are injected from the nozzle 77, and on the -X side, i.e., the downstream side in the direction of rotation of the chuck table 5. This forms an inlet 702 for receiving mist. Note that the first side plate 710 is not required; in that case, the partition plate 161 performs the same function as the first side plate 710.

The upper edge of the inlet 702 of the gas-liquid separation unit 70 described above, i.e., the first edge 705, the slanted edge 706, and the second edge 707, is provided with a canopy 703 that extends downward. The canopy 703 may be positioned perpendicular to the top plate 700 in the -Z direction, or it may be inclined slightly toward the center of the chuck table 5 rather than in the -Z direction. It may also be curved. In the example shown in Figure 4, the canopy 703 has a shorter length in the Z direction on the -X side, i.e., the side closer to the nozzle 77, and a longer length in the Z direction on the +X side, i.e., the side further from the nozzle 77. In this way, the canopy 703 has a shorter length in the Z direction on the side closer to the nozzle 77, and the opening portion is formed to be longer in the Z-axis direction, thereby avoiding collision with the nozzle 77 and allowing for a wider range of motion of the nozzle 77. On the other hand, by making the length in the Z direction on the side of the canopy 703 further from the nozzle 77 longer, more mist can be contained.
Furthermore, by housing the nozzle 77 inside the gas-liquid separation unit 70, passing under the overhang 703 which has a shorter length in the Z direction on the side closer to the nozzle 77, the conveyance of the workpiece 100 to the chuck table 5 is avoided.

As described above, since the top plate 700 is formed in a shape with a portion of a roughly rectangular shape cut out, the area below the uncut portion of the top plate 700 is a large-capacity area 704 with a larger volume that can accommodate more mist.

2. Operation of the processing equipment (loading process)
The operation of the processing apparatus 1 when processing a workpiece 100 using the processing apparatus 1 configured as described above will now be explained. First, as the turntable 6 shown in Figure 1 rotates by a predetermined angle, the chuck table 5, on which the workpiece 100 is not placed, revolves and is positioned in the loading/unloading area 181.

Subsequently, the robot 155 unloads one workpiece 100 from the first cassette 173 and places the workpiece 100 on the table 153 in the temporary storage area 152. Next, while rotating the table 153, the camera 154 images the top surface 101 of the workpiece 100, detects three points on the outer circumference of the workpiece 100, and based on the positions of these three points, the center of the workpiece 100 is detected.

Next, the first transport mechanism 171 uses suction to lift the upper surface 101 of the workpiece 100 and moves it above the chuck table 5 located in the loading/unloading area 181. Then, the workpiece 100 is placed on the holding surface 500 with its upper surface 101 facing upwards, so that the center of the chuck table 5 and the center of the workpiece 100 align. Finally, the workpiece 100 is held in place by the suction force acting on the holding surface 500 by opening the on/off valve 554 shown in Figure 2 and closing the on/off valves 555 and 556.

(Rough grinding process)
After the workpiece 100 is held by suction on the holding surface 500 of the chuck table 5, the turntable 6 is rotated clockwise by a predetermined angle when viewed from the +Z side, causing the chuck table 5 to revolve and move the workpiece 100 held on the chuck table 5 below the rough grinding unit 30 to position it in the rough grinding area 182. At this time, the rough grinding unit 30 and the workpiece 100 are aligned so that when the rough grinding wheel 306 is lowered toward the workpiece 100 and the upper surface 101 of the workpiece 100 comes into contact with the rough grinding wheel 306, the lower surface of the rough grinding wheel 306 passes through the center of rotation of the workpiece 100.

The chuck table 5 is rotated, and the motor 302 rotates the rotating shaft 300 to rotate the rough grinding wheel 306. The motor 202 of the rough grinding feed unit 20 rotates the ball screw 200 to lower the rough grinding wheel, bringing the rough grinding wheel 306 into contact with the upper surface 101 of the workpiece 100.

After the workpiece 100 comes into contact with the rough grinding wheel 306, the rough grinding wheel 306 is further lowered in the -Z direction by a predetermined distance at a predetermined speed, thereby roughly grinding the upper surface 101 of the workpiece 100 to a predetermined thickness. After rough grinding is complete, the rough grinding feed unit 20 raises the rough grinding wheel 306, separating it from the upper surface 101 of the workpiece 100.

(Finishing grinding process)
Subsequently, the turntable 6 is rotated clockwise by a predetermined angle when viewed from the +Z side, causing the chuck table 5 to revolve and move the workpiece 100 held by the chuck table 5 below the finish grinding unit 31 to position it in the finish grinding area 183. When the finish grinding wheel 307 and the workpiece 100 come into contact, the outer circumference of the circle on the lower surface of the finish grinding wheel 307 is aligned to pass through the rotation center of the workpiece 100. Then, similar to the rough grinding process described above, the finish grinding feed unit 21 is used to lower the rotating finish grinding wheel 307 toward the rotating workpiece 100, bringing the finish grinding wheel 307 into contact with the workpiece 100.

After the finishing grinding wheel 307 contacts the workpiece 100, it is further lowered in the -Z direction by a predetermined distance at a predetermined speed to finish grind the upper surface 101 of the workpiece 100. When the workpiece 100 reaches a predetermined finish thickness, the finishing grinding feed unit 21 raises the finishing grinding wheel 307 to end the grinding process.

(polishing process)
Furthermore, by rotating the turntable 6 clockwise by a predetermined angle when viewed from the +Z side, the chuck table 5 is revolved, and the workpiece 100 held by the chuck table 5 is moved below the polishing unit 32. The workpiece 100 is aligned with the polishing pad 324 of the polishing unit 32 so that the polishing pad 324 contacts the entire upper surface 101 of the workpiece 100.

The chuck table 5 is rotated at a predetermined rotational speed, and as the motor 322 rotates the spindle 320, the polishing pad 324 rotates, and the polishing unit 32 is fed in the -Z direction by the polishing feed unit 25, so that the rotating polishing pad 324 comes into contact with the entire upper surface 101 of the workpiece 100.

During polishing, a striped pattern may form on the upper surface 101 of the workpiece 100. This striped pattern may reduce the flexural strength of the workpiece 100. Therefore, during polishing, the X-axis movement unit 24 reciprocates the polishing unit 32 in the X-axis direction, moving the polishing pad 324 on the upper surface 101 of the workpiece 100 in the X-axis direction to prevent the formation of a striped pattern on the upper surface 101.

(Workpiece cleaning process)
After the polishing process described above is completed, the turntable 6 is rotated clockwise by a predetermined angle when viewed from the +Z side, and the polished workpiece 100 is moved to the loading/unloading area 181. In the loading/unloading area 181, the chuck table 5 is rotated, the nozzle 77 is lowered by the lifting actuator 74 shown in Figure 2, and the nozzle 77 is rotated by the swivel motor 71. Air and water are introduced into the nozzle 77 from the air source 75 and water source 76, respectively, and the two fluids 778 are sprayed from the spray unit 775 shown in Figure 3 to clean the upper surface 101 of the workpiece 100. This cleaning process serves purposes such as preventing the transport pad of the second transport mechanism 172 from becoming contaminated when the processed workpiece 100 is transported from the processing area 92 to the loading/unloading area 91.

The two fluids 778 ejected from the nozzle 77 travel from the center of the workpiece 100 towards the gas-liquid separation unit 70. They enter the internal space of the gas-liquid separation unit 70 through its inlet 702, and upon contact with the side plates 701 and top plate 700, are separated into water and air. The air is then released into the atmosphere of the loading/unloading area 181 from the top of the inlet 702 and exhausted to the outside of the processing chamber through an exhaust port of a processing device (not shown), while the water is drained to the outside of the processing chamber 16 through a drain port 162.

Subsequently, once the two-fluid mist is removed from the internal space of the loading/unloading area 181, the nozzle 77 is retracted from above the workpiece 100 by the lifting actuator 74 and the swivel motor 71. Then, the workpiece 100 is transported from the processing area 92 to the spinner cleaning unit 156 in the loading/unloading area 91 by the second transport mechanism 172 shown in Figure 1, and placed on the spinner table 157. As the spinner table 157 rotates, cleaning fluid is sprayed from the nozzle 158 onto the upper surface 101 of the workpiece 100, cleaning the upper surface 101. After cleaning the upper surface 101, the workpiece 100 is picked up by the robot 155 and stored in the second cassette 174.

(Retaining surface cleaning process)
After the processed workpiece is unloaded from the chuck table 5 located in the loading/unloading area 181 by the second transport mechanism 172, if processing debris is attached to the holding surface 500, the holding surface 500 is cleaned by the cleaning unit 7.

As shown in Figure 5, the swivel motor 71 shown in Figure 2 positions the nozzle 77 above the center of the holding surface 500, and the lifting actuator 74 lowers the nozzle 77, bringing the lower end of the side plate closer to the holding surface 500. Then, while rotating the chuck table 5 and swiveling the nozzle 77 with the swivel motor 71, causing it to oscillate radially within the swivel range 79, air is introduced from the air inlet 772 and water from the water inlet 773, and the two fluids are sprayed from the spray unit 775. This ensures that the two fluids reach the entire surface of the holding surface 500, effectively removing processing debris embedded in the porous member 50. During this cleaning process, the on/off valve 555 shown in Figure 2 is opened, and the on/off valves 554 and 556 are closed to perform air blowing from the holding surface 500.

When the two fluids are sprayed toward the holding surface 500, the side plate 784 guides the mist of the two fluids reflected from the holding surface 500 forward, preventing it from scattering. Furthermore, the mist guided forward strikes the front plate 785 and descends, preventing the mist mixed with processing debris from being diffusely reflected and removing it to the outside of the holding surface. Therefore, it is possible to prevent processing debris from scattering and re-adhering to the holding surface 500.

Furthermore, when the two-fluid mixture 778 is ejected from the injection section 775, a negative pressure is created in the gap 783, drawing in outside air from the rear side of the rear plate 781. This outside air is then ejected towards the injection section 775 and guided in the direction of the two-fluid mixture 778's ejection. Therefore, it is possible to prevent the two-fluid mixture 778 ejected from the injection section 775 and the mist of the two-fluid mixture that was diffusely reflected on the holding surface 500 from flowing backward (in the opposite direction to the ejection direction of the two-fluid mixture 778), thus effectively discharging processing debris from the holding surface 500.

Furthermore, even if the mist ejected from the nozzle 777's injection section 775 and the mist removed from the holding surface 500 by the action of the scattering prevention section 786 were to rise upwards, the gas-liquid separation unit 70 is positioned in that direction, so the water mixed with processing debris would be caught, preventing scattering. This water can then be discharged from the discharge section 81 located below the gas-liquid separation unit 70.

In this embodiment, the scattering prevention section is constructed using the rear plate 781, side plates 784, and front plate 785. However, the scattering prevention section can function using only the rear plate 781 and side plates 784, or only the front plate 785.

1: Processing device 10: First device base 11: Second device base 12: First column 13: Second column 14: Third column 150: First cassette mounting section 151: Second cassette mounting section 152: Temporary storage area 153: Table 154: Camera 155: Robot 156: Spinner cleaning unit 157: Spinner table 158: Nozzle 16: Processing chamber 161: Partition plate 162: Drain port 17: Control unit 171: First transport mechanism 172: Second transport mechanism 173: First cassette 174: Second cassette 181: Loading/unloading area 182: Rough grinding area 183: Finish grinding area 184: Polishing area 20: Rough grinding feed unit 200: Ball screw 201: Guide rail 202: Motor 203: Lifting plate 204: Holder 21: Finishing grinding feed unit 24: X-axis movement unit 240: Ball screw 241: Guide rail 242: Motor 243: Movable plate 25: Polishing feed unit 250: Ball screw 251: Guide rail 252: Motor 253: Lifting plate 254: Holder 30: Rough grinding unit 300: Rotating shaft 301: Housing 302: Motor 303: Mount 304: Grinding wheel 305: Wheel base 306: Rough grinding wheel 31: Finishing grinding unit 307: Finishing grinding wheel 32: Polishing unit 320: Spindle 321: Housing 322: Motor 323: Mount 324: Polishing pad 5: Chuck table 50: Porous member 500: Holding surface 51: Frame 52: Support base 53: Shaft part 54: Flow path 551, 552, 553: Flow control valves 554, 555, 556: On/off valves 557: Suction source, 558: Air source, 559: Water source 56: Motor 561: Shaft 562: Drive pulley 563: Driven pulley 564: Belt 6: Turntable 61: Bracket 62: Bearing 7: Washing unit 70: Gas-liquid separation unit 700: Top plate 701: Side plate 702: Inlet 703: Canopy 704: Large capacity area 705: First side 706: Hypotenuse 707: Second side 708: Third side 709: Fourth side 710: First side plate 711: Second side plate 712: Third side plate 71: Swivel motor 72: Nozzle unit 73: Arm 74: Lifting actuator 75: Air source 76: Water source 77: Nozzle 771: Cylinder 772: Air inlet 773: Water inlet 774: Diameter reduction section 775: Injection section 776: Air passage 777: Water passage 778: Two fluids 781: Rear plate 782: Parallel plate 783: Gap (outside air introduction section) 784: Side plate 785: Front plate 786: Scatter prevention section 79: Swivel range 81: Discharge section 91: Loading/unloading area 92: Processing area 100: Workpiece 101: Top surface

Claims (2)

A processing apparatus comprising a chuck table that holds a workpiece by suction on a holding surface having irregularities of a porous member, and a processing unit that grinds or polishes the workpiece held by the holding surface,
The cleaning unit includes a nozzle that sprays a two-fluid mixture of water and air in a spray direction inclined with respect to the holding surface,
The cleaning unit includes a scattering prevention section that prevents the two fluids sprayed from the nozzle from scattering at least to the sides and rear in the spraying direction due to irregularities on the holding surface,
The scattering prevention unit is,
A front plate having a lower surface facing the holding surface and positioned on the front side in the direction of injection of the two fluids , the front plate prevents diffuse reflection of the two fluids by guiding the two fluids forward and causing them to descend upon contact with the front plate ,
A rear plate is positioned on the opposite side of the front plate, with the nozzle in between,
A pair of side plates connected to both sides of the rear plate and surrounding the nozzle together with the rear plate,
It comprises a flat plate connected to the lower end of each of the side plates, extending in a direction parallel to the holding surface and moving away from each other,
Processing equipment. The scattering prevention unit is,
The lower end of the rear plate is further provided with a parallel plate that is parallel to the reduced diameter portion at the lower end of the nozzle and that forms a gap between it and the reduced diameter portion.
The gap between the tip of the parallel plate and the tip of the reduced-diameter portion of the nozzle becomes a negative pressure when the two fluids are ejected from the injection portion provided at the lower end of the reduced-diameter portion, functioning as an outside air intake portion that introduces outside air from the rear side of the rear plate, and the parallel plate also functions as a guide that ejects the introduced outside air toward the injection portion side of the nozzle.
The introduced outside air prevents the scattering of the two fluids backward in the injection direction due to the unevenness of the holding surface .
The processing apparatus according to claim 1.