JP7467653B2 - Grinding device and grinding method - Google Patents

Description

The present disclosure relates to a grinding apparatus and a grinding method.

The processing device described in Patent Document 1 includes a turntable, a pair of holding tables, a processing means, and a water case. The water case has an opening that exposes the turntable, receives processing waste liquid that flows down from the turntable and contains processing waste from the processed workpiece, and drains the waste liquid from a drain outlet.

The grinding device described in Patent Document 2 comprises a holding table, a grinding means which supplies grinding water to perform grinding, a turntable on which two or more holding tables are arranged at equal angles around the rotation axis, and a table cover which covers the top surface of the turntable. The top surface of the table cover is inclined downward from the rotation axis in the outer periphery direction. The grinding water is discharged from the outlet of the water case. A net is set in the outlet of the water case to collect grinding chips mixed in with the grinding water. The grinding chips are removed from the net as appropriate.

The surface processing device described in Patent Document 3 has a partition plate. The partition plate is fixed to an index table and is formed in a cross shape to separate four chucks mounted on the index table. The surface processing device has a casing that houses the chucks and index table, and grinds the substrate with a grinding wheel while supplying grinding fluid to the substrate inside the casing. Brushes are attached to the top and side surfaces of the casing. The brushes come into contact with the top and side surfaces of the partition plate when the chucks are positioned in the processing position.

Japanese Patent Publication No. 2017-222015 Japanese Patent Publication No. 2013-188813 Japanese Patent Publication No. 2010-124006

One aspect of the present disclosure provides a technique for preventing the accumulation of grinding debris around the chuck.

A grinding device according to one aspect of the present disclosure includes a plurality of chucks, a tool driving unit, a table, and a table cover. The chuck holds a substrate. The tool driving unit drives a grinding tool pressed against the substrate. The table holds the plurality of chucks around a rotation center line and rotates about the rotation center line. The table cover rotates together with the table. The table cover includes an inclined portion that slopes downward as it moves away from the rotation center line. The grinding device includes a nozzle. The nozzle supplies cleaning liquid to the inclined portion between the top of the inclined portion and the chuck.

According to one aspect of the present disclosure, accumulation of grinding debris around the chuck can be suppressed.

FIG. 1 is a plan view showing a grinding device according to one embodiment, seen through a top panel of a housing. FIG. 2 is a cross-sectional view showing an example of a tool driving unit. FIG. 3 is a perspective view showing an example of a loading/unloading chamber of a housing. Figure 4(A) is a diagram showing an example of a fixed partition wall, Figure 4(B) is a diagram viewed from the direction of arrow B in Figure 4(A), Figure 4(C) is a diagram viewed through the side wall from the direction of arrow C in Figure 4(A), and Figure 4(D) is a cross-sectional view along line D-D in Figure 4(C). FIG. 5 is a cross-sectional view showing an example of the chuck cover, the table cover, and the base cover. 6A is a top view showing an example of the inner cylinder portion shown in FIG. 5, and FIG. 6B is a top view showing an example of the inner cylinder portion of FIG. 6A with a part of the inner cylinder portion removed. FIG. 7 is a cross-sectional view showing an example of a state in which a part of the inner cylindrical portion shown in FIG. 5 is removed. FIG. 8 is a plan view showing an example of the flow of the cleaning liquid. Figure 9(A) is a cross-sectional view showing an example of an exhaust box, taken along line A-A in Figure 9(B), and Figure 9(B) is a diagram showing an example of a side panel and fixed partition wall as viewed from the direction of arrow B in Figure 9(A). Figure 10(A) is a cross-sectional view showing an example of panning as viewed from the X-axis direction, Figure 10(B) is a cross-sectional view showing an example of panning as viewed from the negative Y-axis direction, and Figure 10(C) is a cross-sectional view showing an example of panning as viewed from the positive Y-axis direction. FIG. 11 is a plan view showing an example of the housing and the tool driving unit shown in FIG. 8. As shown in FIG. FIG. 12 is a plan view showing an example of the arrangement of the liquid level sensor. FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. FIG. 14A is a perspective view showing an example of the exterior of a grinding device, and FIG. 14B is a perspective view showing an example of a recovery section. FIG. 15A is a cross-sectional view showing an example of a destination for storing grinding chips, and FIG. 15B is a cross-sectional view showing an example of a destination after switching.

Below, an embodiment of the present disclosure will be described with reference to the drawings. Note that the same or corresponding configurations in each drawing will be given the same reference numerals, and description thereof may be omitted. In this specification, the X-axis direction, the Y-axis direction, and the Z-axis direction are perpendicular to each other. The X-axis direction and the Y-axis direction are horizontal directions, and the Z-axis direction is vertical.

First, the grinding device 1 will be described with reference to FIG. 1. The grinding device 1 grinds a substrate W. The substrate W includes a semiconductor substrate such as a silicon wafer or a compound semiconductor wafer, or a glass substrate. The substrate W may further include a device layer formed on the surface of the semiconductor substrate or the glass substrate. The device layer includes an electronic circuit. The substrate W may also be a polymer substrate formed by bonding multiple substrates. Grinding includes polishing. The grinding device 1 includes, for example, a table 10, four chucks 20, three tool driving units 30, a housing 40, and a control unit 16.

The control unit 16 is, for example, a computer, and includes a CPU (Central Processing Unit) 17 and a storage medium 18 such as a memory. The storage medium 18 stores programs that control various processes executed in the grinding device 1. The control unit 16 controls the operation of the grinding device 1 by having the CPU 17 execute the programs stored in the storage medium 18.

The table 10 holds the four chucks 20 around the rotation center line R1 and rotates around the rotation center line R1. When viewed from above, the rotation direction of the table 10 can be switched between a clockwise direction and a counterclockwise direction.

The four chucks 20 are arranged at equal intervals around the rotation center line R1 of the table 10. Each chuck 20 rotates with the table 10 and moves to the loading/unloading position A0, the primary grinding position A1, the secondary grinding position A2, the tertiary grinding position A3, and the loading/unloading position A0, in that order.

The loading/unloading position A0 is a position where the substrate W is loaded/unloaded from the chuck 20, and serves as both the position where the substrate W is loaded and the position where the substrate W is unloaded. The primary grinding position A1 is a position where the primary grinding of the substrate W is performed. The secondary grinding position A2 is a position where the secondary grinding of the substrate W is performed. The tertiary grinding position A3 is a position where the tertiary grinding of the substrate W is performed. Note that, although the loading position and the unloading position are the same position in this embodiment, the loading position and the unloading position may be different positions.

The four chucks 20 are attached to the table 10 so as to be rotatable about their respective rotation center lines R2 (see FIG. 2). A chuck driver 19 that drives the chuck 20 is provided for each chuck 20.

The chuck driving unit 19 includes, for example, a motor 19a that rotates the chuck 20. The rotational driving force of the motor 19a is transmitted to the chuck 20 via a timing belt or the like. Note that a gear may be used instead of the timing belt.

One tool driving unit 30 drives the grinding tool D for primary grinding. The tool driving unit 30 rotates and raises and lowers the grinding tool D. Another tool driving unit 30 drives the grinding tool D for secondary grinding. The remaining tool driving unit 30 drives the grinding tool D for tertiary grinding.

Next, the tool driving unit 30 will be described with reference to Figure 2. The tool driving unit 30 includes a movable part 31 to which a grinding tool D is attached. The grinding tool D is pressed against the substrate W to grind the substrate W. The grinding tool D includes, for example, a disk-shaped grinding wheel D1 and a plurality of grinding stones D2 arranged in a ring shape on the lower surface of the grinding wheel D1.

The movable part 31 has a flange 32 on which the grinding tool D is attached, a spindle shaft 33 on whose lower end the flange 32 is provided, and a spindle motor 34 that rotates the spindle shaft 33. The flange 32 is arranged horizontally, and the grinding tool D is attached to its underside. The spindle shaft 33 is arranged vertically. The spindle motor 34 rotates the spindle shaft 33, thereby rotating the grinding tool D attached to the flange 32. The rotation center line R3 of the grinding tool D is the rotation center line of the spindle shaft 33.

The tool driving unit 30 further has a lifting unit 35 that raises and lowers the movable unit 31. The lifting unit 35 has, for example, a vertical Z-axis guide 36, a Z-axis slider 37 that moves along the Z-axis guide 36, and a Z-axis motor 38 that moves the Z-axis slider 37. The movable unit 31 is fixed to the Z-axis slider 37, and the movable unit 31 and grinding tool D rise and fall together with the Z-axis slider 37. The lifting unit 35 further has a position detector 39 that detects the position of the grinding tool D. The position detector 39 detects, for example, the rotation of the Z-axis motor 38 to detect the position of the grinding tool D.

The lifting unit 35 lowers the grinding tool D from the standby position. The grinding tool D rotates as it descends, contacting the top surface of the rotating substrate W and grinding the entire top surface of the substrate W. When the thickness of the substrate W reaches a set value, the lifting unit 35 stops the descent of the grinding tool D. The lifting unit 35 then raises the grinding tool D to the standby position.

The grinding device 1 includes a housing 40 that houses multiple chucks 20. The housing 40 prevents grinding debris and grinding fluid from scattering to the outside. The grinding debris is powder or debris generated by grinding the substrate W. The powder includes powder cut out from the substrate W and abrasive grains detached from the grinding tool D. The debris is, for example, arc-shaped flakes generated at the periphery of the substrate W. The housing 40 may also house the table 10.

The housing 40 has a top panel 41 located above the chuck 20 and a side panel 42 located to the side of the chuck 20. The top panel 41 is horizontal and the side panel 42 is vertical. The top panel 41 is located above the side panel 42. An insertion opening 41a for the movable part 31 is formed in the top panel 41.

1, the top panel 41 covers, for example, the top of the primary grinding position A1, the secondary grinding position A2, and the tertiary grinding position A3. The top panel 41 also opens up above the loading/unloading position A0. For example, when viewed from above, the top panel 41 has a rectangular shape with one corner cut out in an L-shape.

As shown in FIG. 2, the grinding device 1 is equipped with a nozzle 50 that supplies grinding fluid to the substrate W held by the chuck 20. The grinding fluid is, for example, pure water such as DIW (Deionized Water). The grinding fluid penetrates between the substrate W and the grinding tool D, reducing the grinding resistance and suppressing the generation of heat. The nozzle 50 can also supply pure water as a cleaning fluid for the chuck 20 to the chuck 20 after the substrate W has been removed.

As shown in Figure 1, the grinding device 1 has fixed partition walls 45 that divide the interior of the housing 40 into multiple rooms around the rotation center line R1 of the table 10. The fixed partition walls 45 are fixed to the lower surface of the upper panel 41. When viewed from above, the fixed partition walls 45 extend in the radial direction of the table 10 (in a direction perpendicular to the rotation center line R1).

The fixed partition wall 45 is arranged, for example, in a cross shape, and divides the inside of the housing 40 into four rooms B0 to B3 around the rotation center line R1 of the table 10. The three rooms B1 to B3 are grinding chambers where grinding of the substrate W is performed. B1 is the primary grinding chamber, B2 is the secondary grinding chamber, and B3 is the tertiary grinding chamber. The remaining room B0 is a load/unload chamber where the substrate W is loaded and unloaded. Loading and unloading of the substrate W includes the transfer of the substrate W between an external transport device and the chuck 20.

When viewed from above, the interior of the housing 40 is partitioned in a counterclockwise direction into a loading/unloading chamber B0, a primary grinding chamber B1, a secondary grinding chamber B2, and a tertiary grinding chamber B3, in that order. Note that the order of the four chambers B0 to B3 may be reversed, and when viewed from above, the interior of the housing 40 may be partitioned in a clockwise direction into a loading/unloading chamber B0, a primary grinding chamber B1, a secondary grinding chamber B2, and a tertiary grinding chamber B3, in that order.

3, the grinding device 1 has a plurality of rotating partition walls 15 that rotate together with the table 10. Each of the plurality of rotating partition walls 15 is located between a plurality of chucks 20 adjacent to each other in the circumferential direction of the table 10, rotates together with the table 10, stops directly below the fixed partition wall 45, and contacts the lower end of the fixed partition wall 45. The fixed partition wall 45 and the rotating partition wall 15 suppress the movement of grinding chips and grinding fluid between adjacent rooms. Note that the upper end of the rotating partition wall 15 and the lower end of the fixed partition wall 45 do not have to contact each other.

For example, the fixed partition wall 45 and the rotating partition wall 15 prevent grinding chips and the like from entering the loading/unloading chamber B0 from the primary grinding chamber B1 and the tertiary grinding chamber B3, keeping the loading/unloading chamber B0 clean. The fixed partition wall 45 and the rotating partition wall 15 also prevent primary grinding chips with large particle sizes from entering the secondary grinding chamber B2 from the primary grinding chamber B1, preventing roughness of the grinding surface after secondary grinding. Furthermore, the fixed partition wall 45 and the rotating partition wall 15 prevent secondary grinding chips with large particle sizes from entering the tertiary grinding chamber B3 from the secondary grinding chamber B2, preventing roughness of the grinding surface after tertiary grinding.

4, the fixed partition wall 45 includes an upper wall 100 extending in the radial direction of the table 10 (the Y-axis direction in FIG. 4), a first upper sheet 111 suspended from the upper wall 100 along the upper wall 100, and a second upper sheet 112 facing the first upper sheet 111 at a distance. The first upper sheet 111 and the second upper sheet 112 are, for example, resin sheets or rubber sheets.

Unlike the brush described in Patent Document 3, the first upper sheet 111 and the second upper sheet 112 inhibit the movement of grinding chips and grinding fluid with a surface rather than a line. Furthermore, the first upper sheet 111 and the second upper sheet 112 doubly inhibit the movement of grinding chips and grinding fluid. Therefore, the movement of grinding chips and grinding fluid between adjacent rooms can be inhibited more than before.

4(B), the upper wall 100 has at its lower end a horizontal portion 101 extending in the radial direction of the table 10, and a vertical portion 102 protruding downward from one end of the horizontal portion 101 in the width direction. The horizontal portion 101 and the vertical portion 102 form an L-shaped angle 103. The fixed partition wall 45 has a fastener that fastens the first upper sheet 111 and the second upper sheet 112 to the vertical portion 102. The fastener is not particularly limited, but is, for example, a bolt 120.

A plurality of bolts 120 are provided at intervals in the radial direction of the table 10. The shaft portion 121 of the bolt 120 passes through a through hole in the first upper sheet 111 and a through hole in the second upper sheet 112, and is screwed into a bolt hole in the vertical portion 102. The head portion 122 of the bolt 120 presses the first upper sheet 111 and the second upper sheet 112 via a pressing plate 123 or the like.

The first upper sheet 111 or the second upper sheet 112 can be replaced by loosening or tightening the bolt 120. It is also possible to change the dimensions or shape of the first upper sheet 111 before or after replacing the first upper sheet 111. The same applies to the second upper sheet 112.

When viewed from above, the first upper sheet 111, the second upper sheet 112, and the head 122 of the bolt 120 do not protrude from the horizontal portion 101. Interference between the head 122 of the bolt 120 and other components can be suppressed.

The first upper sheet 111 and the second upper sheet 112 are arranged with the spacers 114, 115 in between, and protrude downward beyond the spacers 114, 115. The spacers 114, 115 are formed with a through hole through which the shaft portion 121 of the bolt 120 passes.

The fixed partition wall 45 may further include a third upper sheet 113 disposed between the first upper sheet 111 and the second upper sheet 112. The third upper sheet 113 is, for example, a resin sheet or a rubber sheet. The first upper sheet 111, the second upper sheet 112, and the third upper sheet 113 triple impede the movement of grinding chips and grinding fluid.

The third upper sheet 113 and the first upper sheet 111 are arranged with a spacer 114 in between, and protrude downward beyond the spacer 114. The third upper sheet 113 and the second upper sheet 112 are arranged with a spacer 115 in between, and protrude downward beyond the spacer 115.

As shown by the two-dot chain line in Figure 4 (B), the upper end of the rotating partition wall 15 may have an upwardly convex curved surface when viewed from the radial direction of the table 10. The third upper sheet 113 contacts the upper end of the rotating partition wall 15. On the other hand, the first upper sheet 111 and the second upper sheet 112 do not contact the upper end of the rotating partition wall 15.

The third upper sheet 113 contacts the upper end of the rotating partition wall 15. Thus, the thickness T3 of the third upper sheet 113 may be thicker than the thickness T1 of the first upper sheet 111 and the thickness T2 of the second upper sheet 112. This achieves both the durability of the third upper sheet 113 and the flexibility of the first upper sheet 111 and the second upper sheet 112. The first upper sheet 111 and the second upper sheet 112 may contact the upper end of the rotating partition wall 15 and deform to conform to the upper end.

In addition, a member other than the third upper sheet 113, for example a brush, may be arranged between the first upper sheet 111 and the second upper sheet 112. In addition, neither the third upper sheet 113 nor a brush may be arranged between the first upper sheet 111 and the second upper sheet 112, and nothing may be arranged at all. Various sealing members can be replaced by the bolts 120, and the number of sealing members can be changed. If the third upper sheet 113 is not present, either or both of the first upper sheet 111 and the second upper sheet 112 contact the upper end of the rotating partition wall 15. In addition, if the third upper sheet 113 is not present, both the first upper sheet 111 and the second upper sheet 112 do not need to contact the upper end of the rotating partition wall 15.

The fixed partition wall 45 includes a side wall 130 located between the upper wall 100 and the side panel 42 and projecting downward from the upper wall 100, a first horizontal sheet 141 projecting from the side wall 130 toward the table 10, and a second horizontal sheet 142 facing the first horizontal sheet 141 at a distance. The first horizontal sheet 141 and the second horizontal sheet 142 are, for example, resin sheets or rubber sheets.

As shown in FIG. 4(C), the first horizontal sheet 141 is arranged, for example, on the same plane as the first upper sheet 111. The thickness of the first horizontal sheet 141 may be the same as the thickness T1 of the first upper sheet 111. Furthermore, the second horizontal sheet 142 is arranged, for example, on the same plane as the second upper sheet 112. The thickness of the second horizontal sheet 142 may be the same as the thickness T2 of the second upper sheet 112.

Unlike the brush described in Patent Document 3, the first horizontal sheet 141 and the second horizontal sheet 142 inhibit the movement of grinding chips and grinding fluid with a surface rather than a line. Furthermore, the first horizontal sheet 141 and the second horizontal sheet 142 inhibit the movement of grinding chips and grinding fluid doubly. Therefore, the movement of grinding chips and grinding fluid between adjacent rooms can be inhibited more than before.

The fixed partition wall 45 may further include a third horizontal sheet 143 disposed between the first horizontal sheet 141 and the second horizontal sheet 142. The third horizontal sheet 143 is, for example, a resin sheet or a rubber sheet.

The third horizontal sheet 143 is arranged, for example, on the same plane as the third upper sheet 113. The thickness of the third horizontal sheet 143 may be the same as the thickness T3 of the third upper sheet 113. The thickness of the third horizontal sheet 143 is thicker than the thickness of the first horizontal sheet 141 and the thickness of the second horizontal sheet 142.

As shown in FIG. 4(C), the third horizontal sheet 143 protrudes upward from the first horizontal sheet 141 and the second horizontal sheet 142, and is inserted between the first upper sheet 111 and the second upper sheet 112. As a result, even if there is a gap between the first upper sheet 111 and the first horizontal sheet 141, the gap can be blocked by the third horizontal sheet 143, and the movement of grinding chips and grinding fluid through the gap can be inhibited. Similarly, even if there is a gap between the second upper sheet 112 and the second horizontal sheet 142, the gap can be blocked by the third horizontal sheet 143, and the movement of grinding chips and grinding fluid through the gap can be inhibited.

As shown in Figure 4 (D), the first upper sheet 111 and the second upper sheet 112 protrude further toward the side wall 130 than the third upper sheet 113. As a result, even if there is a gap between the third upper sheet 113 and the third lateral sheet 143, the gap can be sandwiched and hidden between the first upper sheet 111 and the second upper sheet 112, and the movement of grinding chips and grinding fluid through the gap can be inhibited.

Next, the chuck cover 70 and the like will be described with reference to Figure 5. As shown in Figure 5, the grinding apparatus 1 is equipped with a chuck cover 70 that rotates together with the chuck 20. The chuck 20 includes a holding table 21 that holds the substrate W, and a flange 23 provided on the lower edge of the holding table 21. The holding table 21 has a porous body 21a and a base 21b. A recess is formed on the upper surface of the base 21b, and a disk-shaped porous body 21a is embedded in the recess.

When the gas inside the porous body 21a is sucked in and the air pressure inside the porous body 21a becomes a negative pressure lower than atmospheric pressure, the substrate W is adsorbed to the porous body 21a. On the other hand, when the gas suction is stopped and the air pressure inside the porous body 21a is returned to atmospheric pressure, the adsorption of the substrate W is released.

The chuck 20 is placed on the rotating table 25 and fixed to the rotating table 25 by a fixing device. The fixing device is not particularly limited, but is, for example, a bolt 24. A plurality of bolts 24 are provided at intervals around the circumference of the flange 23 of the chuck 20. The shaft portion of the bolt 24 passes through a through hole in the flange 23 and is screwed into a bolt hole in the rotating table 25. The head of the bolt 24 presses the flange 23 from above. The chuck 20 can be replaced by loosening and tightening the bolt 24.

The chuck cover 70 includes an annular eaves portion 71. The annular eaves portion 71 has an opening 71a in its center into which the holding base 21 of the chuck 20 fits. The upper surface of the eaves portion 71 is positioned at the same height as the upper surface of the holding base 21 of the chuck 20 or lower than the upper surface of the holding base 21. The upper surface of the eaves portion 71 is also positioned above the inclined portion 61 of the table cover 60, which will be described later.

The upper surface of the eaves portion 71 slopes downward as it moves away from the rotation center line R2 of the chuck 20. The upper surface of the eaves portion 71 may be horizontal. However, if the upper surface of the eaves portion 71 is inclined, the grinding fluid can be discharged diagonally downward by gravity, and the accumulation of grinding chips mixed in the grinding fluid can be suppressed. The upper surface of the eaves portion 71 has, for example, a conical shape.

The eaves portion 71 is positioned above the flange 23 of the chuck 20 and covers the bolt 24, which is a fixing device, from above. The diameter of the opening 71a formed in the center of the eaves portion 71 is larger than the diameter of the holding base 21 and smaller than the diameter of the flange 23. The bolt 24 can be hidden directly below the eaves portion 71, preventing the grinding fluid from hitting the bolt 24 and preventing the grinding fluid from splashing.

According to this embodiment, the chuck cover 70 rotates together with the chuck 20. When the chuck 20 is rotated during grinding of the substrate W, the eaves portion 71 rotates, and the grinding fluid attached to the eaves portion 71 can be blown radially outward by centrifugal force. This prevents the accumulation of grinding debris mixed in the grinding fluid, and prevents the grinding debris from accumulating around the chuck 20. As a result, it is possible to prevent the operator or working robot from becoming dirty during maintenance such as replacing the chuck 20 or the grinding tool D. In addition, it is possible to prevent the accumulated grinding debris from peeling off and adhering to the chuck 20 or the substrate W.

A spacer 28 is provided between the eaves portion 71 of the chuck cover 70 and the flange 23 of the chuck 20. A plurality of spacers 28 are provided at intervals around the circumference of the flange 23. The eaves portion 71 is placed on the plurality of spacers 28. The spacer 28 may be integrated with the eaves portion 71. In that case, the spacer 28 is placed on the flange 23, and the shaft portion of the bolt 29 described later is screwed into the bolt hole of the flange 23.

The spacer 28 forms a gap between the eaves portion 71 and the flange 23. Compared to when there is no gap, the thickness of the eaves portion 71 can be made thinner, making the eaves portion 71 lighter. In addition, space can be secured between the eaves portion 71 and the flange 23 to position the head of the bolt 24.

The spacer 28 has a bolt hole on its upper surface. The shaft of a bolt 29 that fixes the eaves portion 71 to the spacer 28 is screwed into the bolt hole. The head of the bolt 29 presses the eaves portion 71 from above. A groove 71b extending in the radial direction of the chuck 20 is formed in the upper surface of the eaves portion 71. The groove 71b accommodates the head of the bolt 29, and the head of the bolt 29 presses the bottom surface of the groove 71b from above. The head of the bolt 29 and the bottom surface of the groove 71b are horizontal.

The upper surface of the eaves portion 71 is inclined, whereas the lower surface of the eaves portion 71 is horizontal. If the lower surface of the eaves portion 71 is horizontal, the eaves portion 71 can be stably placed on a plurality of spacers 28. The number of spacers 28 is preferably three or more.

The chuck cover 70 includes an outer cylinder portion 77 that extends downward from the periphery of the eaves portion 71. In FIG. 5, the outer cylinder portion 77 extends straight down, but it may extend diagonally downward. The outer cylinder portion 77 extends downward beyond the upper end of the inner cylinder portion 67 of the table cover 60 described below, and surrounds the inner cylinder portion 67. The inner cylinder portion 67 and the outer cylinder portion 77 form a labyrinth that prevents the infiltration of grinding fluid.

The boundary between the eaves portion 71 and the outer tube portion 77 has, for example, a chamfered shape and a curved shape. In the case of a broken line-shaped boundary, the surface tension of the droplets prevents the droplets from crossing the boundary. As a result, a ring-shaped pool of liquid is likely to form. If the boundary between the eaves portion 71 and the outer tube portion 77 has a curved shape, the droplets can easily cross the boundary, and the grinding fluid can be easily discharged. Therefore, it is possible to prevent grinding chips mixed in the grinding fluid from accumulating in a ring shape.

As shown in Figure 5, the grinding device 1 has a table cover 60 that rotates together with the table 10. The table cover 60 has an inclined portion 61 that slopes downward as it moves away from the rotation center line R1 of the table 10.

The inclined portion 61 is positioned below the upper surface of the holding table 21 of the chuck 20 and above the table 10. Unlike the horizontal plate portion, the inclined portion 61 can discharge the grinding fluid diagonally downward by gravity. This makes it possible to suppress the accumulation of grinding chips mixed in with the grinding fluid.

The inclined portion 61 has, for example, a conical shape with a constant height in the circumferential direction of the table 10. When the inclined portion 61 has a conical shape, the grinding fluid can be discharged radially as shown by the arrows in Figure 3, and the accumulation of grinding debris around the chuck 20 can be suppressed.

Incidentally, the inclined portion 61 may have a pyramidal shape. However, when the inclined portion 61 has a pyramidal shape, a groove G is formed as shown by the two-dot chain line in Figure 3. The chuck 20 is located at the bottom of the groove G, and the grinding fluid tends to collect near the chuck 20, so that grinding chips mixed with the grinding fluid tend to accumulate.

As shown in Figure 5, the inclined portion 61 forms an opening 61a between the top and bottom, into which the turntable 25 fits. A plurality of openings 61a are formed for each turntable 25, with a space between them around the rotation center line R1 of the table 10. The plurality of openings 61a are formed, for example, at equal intervals.

The table cover 60 includes an inner cylinder portion 67 that rises upward from the edge of the opening 61a of the inclined portion 61. In FIG. 5, the inner cylinder portion 67 rises straight up, but it may rise diagonally upward. The upper edge of the inner cylinder portion 67 is horizontal over the entire circumferential direction. The inner cylinder portion 67 prevents the grinding fluid from entering the opening 61a.

As shown in Fig. 6 (A), the inner cylinder portion 67 includes a first arc cylinder portion 67a, a second arc cylinder portion 67b, and a connecting portion 67c. The first arc cylinder portion 67a is fixed to the inclined portion 61. The second arc cylinder portion 67b is removably connected to the first arc cylinder portion 67a. The connecting portion 67c connects the first arc cylinder portion 67a and the second arc cylinder portion 67b in an annular shape.

The connecting portion 67c includes, for example, a connecting plate 67c1 and a bolt 67c2. The connecting plate 67c1 is fixed, for example, to the inner circumferential surface of the second arc tube portion 67b and extends to the inner circumferential surface of the first arc tube portion 67a. The shaft portion of the bolt 67c2 passes through a through hole in the first arc tube portion 67a and is screwed into a bolt hole in the connecting plate 67c1. The head of the bolt 67c2 presses the first arc tube portion 67a from the radial outside.

The structure of the connecting portion 67c is not particularly limited. For example, the connecting plate 67c1 may be fixed to the inner circumferential surface of the first arc-shaped cylindrical portion 67a and extend to the inner circumferential surface of the second arc-shaped cylindrical portion 67b. In this case, the shaft of the bolt 67c2 passes through a through hole of the second arc-shaped cylindrical portion 67b and is screwed into the bolt hole of the connecting plate 67c1. The head of the bolt 67c2 presses the second arc-shaped cylindrical portion 67b from the radial outside.

In any case, the second arc-shaped cylindrical portion 67b can be removed or attached by loosening or tightening the bolt 67c2. As is clear from FIG. 6B, removing the second arc-shaped cylindrical portion 67b makes it easy to replace the chuck 20.

As shown in FIG. 5, the second arc-shaped cylindrical portion 67b is disposed radially outward of the table 10 relative to the first arc-shaped cylindrical portion 67a. At least a portion of the lower edge of the second arc-shaped cylindrical portion 67b is disposed below the upper surface of the rotating table 25.

As a result, by removing the second arcuate cylinder portion 67b, the chuck 20 placed on the upper surface of the rotating table 25 can be pulled out sideways as shown in Figure 7. This is effective when the adhesion between the chuck 20 and the rotating table 25 is strong and the chuck 20 cannot be pulled off upwards.

As shown in FIG. 5, the inner cylinder portion 67 may further include a third arc-shaped cylinder portion 67d on which the second arc-shaped cylinder portion 67b is placed. The third arc-shaped cylinder portion 67d may be fixed to the inclined portion 61 and integrated with the first arc-shaped cylinder portion 67a.

The inner cylinder portion 67 may further include an alignment portion 67e that aligns the second arc cylinder portion 67b and the third arc cylinder portion 67d. The alignment portion 67e is, for example, fixed to the inner peripheral surface of the second arc cylinder portion 67b, inserted into the inside of the third arc cylinder portion 67d, and contacts the inner peripheral surface to align the second arc cylinder portion 67b and the third arc cylinder portion 67d.

The table cover 60 has a cylindrical portion 63 that extends downward from the lower edge of the inclined portion 61. The cylindrical portion 63 extends straight down in FIG. 5, but may extend diagonally downward. The cylindrical portion 63 drops the grinding fluid outside the table 10. The outer diameter of the cylindrical portion 63 is larger than the diameter of the table 10.

The boundary between the inclined portion 61 and the cylindrical portion 63 has, for example, a chamfered shape and a curved shape. Compared to a broken-line shaped boundary, droplets are more likely to cross the boundary, and the grinding fluid is more likely to be discharged. This makes it possible to prevent grinding chips mixed in with the grinding fluid from accumulating in a ring shape.

The inclined portion 61 forms an opening 61b at its top through which the fixed shaft 11 passes. The table cover 60 has a central cylinder 69 that rises upward from the edge of the opening 61b of the inclined portion 61. The central cylinder 69 rises straight up in FIG. 5, but it may also rise diagonally upward. The central cylinder 69 prevents grinding fluid from entering the opening 61b.

The table cover 60 is divided into multiple split covers in the circumferential direction of the table 10. The number of split covers is the same as the number of chucks 20. A rotating partition wall 15 is disposed between adjacent split covers in the circumferential direction.

The multiple split covers are individually and removably attached to the table 10. When performing maintenance, the split covers can be removed individually, without having to remove the entire table cover 60, improving workability.

The grinding device 1 includes a base cover 90. The base cover 90 has a horizontal disk portion 91. The disk portion 91 is disposed below the table cover 60 and above the table 10, and is disposed concentrically with the table 10. The diameter of the disk portion 91 is larger than the diameter of the table 10.

The disk portion 91 forms an opening 91a through which the rotation shaft 26 of the chuck 20 passes, around the rotation center line R1 of the table 10. A plurality of openings 91a are formed at equal intervals around the rotation center line R1 of the table 10.

The base cover 90 includes an inner cylinder portion 93 that rises upward from the edge of the opening 91a. In FIG. 5, the inner cylinder portion 93 rises straight up, but it may rise diagonally upward. The rotating shaft 26 is inserted into the inner cylinder portion 93.

The rotating shaft 26 extends vertically downward from the center of rotation of the rotating table 25. An outer cylinder portion 27 extending downward is provided on the periphery of the rotating table 25. The outer cylinder portion 27 extends directly downward in FIG. 5, but may extend diagonally downward.

The outer cylinder portion 27 extends downward beyond the upper end of the inner cylinder portion 93 of the base cover 90 and surrounds the inner cylinder portion 93. The inner cylinder portion 93 and the outer cylinder portion 27 form a labyrinth that prevents the infiltration of grinding fluid.

As described above, multiple openings 91a are arranged at equal intervals around the rotation center line R1 of the table 10. A rotating partition wall 15 is arranged between adjacent openings 91a in the circumferential direction of the table 10. The rotating partition wall 15 is provided on the disk portion 91.

The base cover 90 has a tubular portion 94 that extends downward from the periphery of the disk portion 91. The tubular portion 94 extends directly downward in FIG. 5, but may extend diagonally downward.

The boundary between the disk portion 91 and the tube portion 94 has, for example, a chamfered shape and a curved shape. Compared to a broken line shape, droplets can easily overcome the boundary, and the grinding fluid can be easily discharged. Therefore, it is possible to prevent grinding chips mixed in with the grinding fluid from accumulating in a ring shape.

As shown in FIG. 5, the grinding device 1 is provided with a nozzle 51 that supplies cleaning liquid to the inclined portion 61 between the top of the inclined portion 61 of the table cover 60 and the chuck 20. The nozzle 51 supplies cleaning liquid to the inclined portion 61 from above. The nozzle 51 may be provided in the central tube portion 69. The cleaning liquid is, for example, pure water. After being supplied to the inclined portion 61, the cleaning liquid flows diagonally downward due to gravity. The cleaning liquid can clean a wide range of the inclined portion 61, and can prevent grinding debris from accumulating around the chuck 20. The nozzle 51 may supply cleaning liquid to the inclined portion 61 at a position where the cleaning liquid reaches the top of the inclined portion 61. The entire inclined portion 61 can be cleaned from the top to the bottom.

The nozzle 51 ejects cleaning liquid, for example, when grinding the substrate W, to wash away the grinding liquid and grinding debris adhering to the inclined portion 61. The nozzle 51 is provided not only in the primary grinding chamber B1, but also in the secondary grinding chamber B2 and the tertiary grinding chamber B3. The nozzle 51 may also be provided in the load/unload chamber B0. The nozzle 51 may eject cleaning liquid at times other than when the substrate W is being grinded.

The inclined portion 61 of the table cover 60 forms an opening 61b at its top through which the fixed shaft 11 passes. A central tube portion 69 rises from the edge of the opening 61b, and a nozzle 51 is disposed radially outward of the central tube portion 69. This prevents cleaning liquid from penetrating inside the central tube portion 69.

The grinding device 1 includes a measuring device 95 for measuring the thickness of the substrate W. The measuring device 95 includes a nozzle 51. Inside the measuring device 95, flow paths L1 and L2 for the cleaning liquid are formed. The flow path L2 passes through the base end of at least one of the first arm 95c and the second arm 95d described later. The cleaning liquid passes through the flow path L2, absorbs heat from the first height sensor 95a via the first arm 95c, and is discharged from the nozzle 51. Alternatively, the cleaning liquid passes through the flow path L2, absorbs heat from the second height sensor 95b via the second arm 95d, and is discharged from the nozzle 51. At least one of the first height sensor 95a and the second height sensor 95b can be cooled by the cleaning liquid. The cooling flow path L2 may be formed separately from the flow path L1 for the nozzle.

The measuring device 95 includes, for example, a first height sensor 95a that measures the height of the substrate W and a second height sensor 95b that measures the height of the chuck 20. The thickness of the substrate W can be measured from the difference between the height of the substrate W and the height of the chuck 20. Note that although the measuring device 95 is of a contact type in FIG. 5, it may be of a non-contact type.

The measuring device 95 includes a first arm 95c that holds the first height sensor 95a, a second arm 95d that holds the second height sensor 95b, and a bracket 95e that holds the first arm 95c and the second arm 95d. A nozzle 51 is provided on the underside of the bracket 95e.

The bracket 95e of the measuring device 95 is attached to the upper surface of the fixed shaft 11 and protrudes radially outward from the fixed shaft 11. The nozzle 51 is provided on the lower surface of the bracket 95e at a portion protruding radially outward from the fixed shaft 11, and supplies cleaning liquid to the inclined portion 61.

As shown in FIG. 8, the supply ports 51a of the nozzle 51 are provided at intervals in the circumferential direction of the table cover 60 (the rotation direction of the table cover 60). Multiple supply ports 51a may be provided in one room (e.g., the primary grinding room B1). The multiple supply ports 51a allow a wide circumferential range of the inclined portion 61 of the table cover 60 to be cleaned simultaneously. The supply port 51a of the nozzle 51 is an arc-shaped slit that runs along the circumferential direction of the table cover 60. The cleaning liquid can be supplied to a position close to the top of the inclined portion 61 of the table cover 60. The supply port 51a of the nozzle 51 may be a straight slit or a circular hole.

However, at the bottom of the inclined portion 61, the surface tension of the droplets prevents the droplets from climbing over the bottom. As a result, a ring-shaped pool of liquid is easily formed, and the ring-shaped dirt is easily attached.

The grinding device 1 is therefore equipped with nozzles 52-1, 52-2 that supply cleaning liquid from above to the bottom of the inclined portion 61 of the table cover 60. The cleaning liquid is, for example, pure water. The cleaning liquid washes away the grinding liquid contaminated with grinding debris, preventing the ring-shaped dirt from adhering.

Nozzle 52-1 is located, for example, near the boundary between primary grinding chamber B1 and loading/unloading chamber B0. "Near the boundary" refers to a range within 50 mm from fixed partition wall 45, which is the boundary. At least a part of the nozzle 52-1 outlet needs to be within that range.

On the other hand, nozzle 52-2 is located near the boundary between the tertiary grinding chamber B3 and the load/unload chamber B0. "Near the boundary" refers to a range within 50 mm from the fixed partition wall 45, which is the boundary. It is sufficient that at least a part of the outlet of nozzle 52-2 is within that range.

While the table 10 is rotating in a clockwise direction as viewed from above, the control unit 16 supplies cleaning liquid to the bottom of the inclined portion 61 of the table cover 60 from the nozzle 52-1 arranged in the primary grinding chamber B1. The bottom of the inclined portion 61 can be cleaned immediately before it moves from the primary grinding chamber B1 to the load/unload chamber B0, preventing dirt from being brought into the load/unload chamber B0.

Meanwhile, while the table 10 is rotating counterclockwise as viewed from above, the control unit 16 supplies cleaning liquid to the bottom of the inclined portion 61 of the table cover 60 from the nozzle 52-2 arranged in the tertiary grinding chamber B3. The bottom of the inclined portion 61 can be cleaned immediately before it moves from the tertiary grinding chamber B3 to the load/unload chamber B0, preventing dirt from being brought into the load/unload chamber B0.

8, the grinding device 1 is provided with an exhaust box 43 located outside the housing 40 and exhausting gas from the housing 40. The exhaust box 43 is connected to a suction source (not shown) via piping 44. The suction source is, for example, a vacuum pump or an ejector. The suction source may be part of a factory facility. The piping 44 is installed, for example, on the ceiling 43a of the exhaust box 43. The exhaust box 43 exhausts gas from inside the housing 40 by the suction force of the suction source, making the inside of the housing 40 at a negative pressure compared to the outside of the housing 40, and suppressing leakage of grinding chips and grinding fluid.

The three exhaust boxes 43 individually exhaust gas from the three grinding chambers B1 to B3, creating a negative pressure in the three grinding chambers B1 to B3 relative to the pressure outside the housing 40. The air pressure in the loading/unloading chamber B0 is higher than the air pressure in the grinding chambers B1 to B3. This pressure difference limits the scattering of grinding chips and grinding fluid from the grinding chambers B1 to B3 to the loading/unloading chamber B0.

The number of exhaust boxes 43 and the number of grinding chambers are not limited to three. The number of exhaust boxes 43 and the number of pipes 44 do not have to be the same. For example, one pipe 44 may be connected across two adjacent exhaust boxes 43.

Incidentally, when exhausting gas from inside the housing 40, the exhaust box 43 also exhausts droplets of grinding fluid from inside the housing 40. The droplets of grinding fluid contain grinding chips generated during grinding.

Therefore, as shown in FIG. 9, the side panel 42 of the housing 40 includes a liquid receiving portion 42a, an exhaust port 42b, and a return port 42c to prevent the grinding fluid contaminated with grinding debris from being discharged outside the grinding device 1 together with the gas.

The liquid receiving portion 42a is located at the same height as the substrate W held by the chuck 20 and receives the grinding fluid that splashes horizontally from the upper surface of the substrate W. The liquid receiving portion 42a restricts a large amount of grinding fluid from entering the exhaust box 43.

The exhaust port 42b is located above the liquid receiving portion 42a, for example, directly above the liquid receiving portion 42a. After hitting the liquid receiving portion 42a, the grinding fluid falls downward due to gravity, so very little of it enters the exhaust port 42b.

The exhaust port 42b is connected to the inside of the exhaust box 43. The exhaust box 43 exhausts gas from inside the housing 40 through the exhaust port 42b. The gas contains droplets of grinding fluid.

The exhaust box 43 separates the grinding fluid droplets from the gas inside. The grinding fluid droplets have a higher density than the gas and separate from the gas due to gravity, etc. The separated grinding fluid falls.

The return port 42c is located below the liquid receiving portion 42a, for example, directly below the liquid receiving portion 42a. The return port 42c returns the grinding fluid separated from the gas inside the exhaust box 43 to the inside of the housing 40. This makes it possible to prevent the grinding fluid contaminated with grinding debris from being discharged to the outside of the grinding device 1 together with the gas.

The exhaust box 43 has an inclined surface 43b that guides the grinding fluid separated from the gas inside the exhaust box 43 diagonally downward toward the return port 42c of the side panel 42. The further downward the inclined surface 43b is, the closer it is to the side panel 42. The grinding fluid flows down along the inclined surface 43b. This flow can prevent dirt from adhering to the inclined surface 43b.

The inclined surface 43b of the exhaust box 43 approaches the side panel 42 as it moves downward, for example, from a position higher than the exhaust port 42b of the side panel 42 to a position at the same height as the return port 42c of the side panel 42. After passing through the exhaust port 42b of the side panel 42 together with the gas, droplets of the grinding fluid adhere to the inclined surface 43b of the exhaust box 43 and flow down along the inclined surface 43b.

The grinding device 1 may be provided with a nozzle 53 that supplies cleaning liquid to the inside of the housing 40 through the inside of the exhaust box 43. The cleaning liquid is, for example, pure water such as DIW. After being supplied to the inside of the exhaust box 43, the cleaning liquid passes through the return port 42c of the side panel 42 and is supplied to the inside of the housing 40. Unlike grinding fluid, the cleaning liquid does not contain dirt such as grinding chips, so the inside of the exhaust box 43 and the inside of the housing 40 can be cleaned.

The nozzle 53 is provided, for example, on the inclined surface 43b of the exhaust box 43. The cleaning liquid flows down along the inclined surface 43b. This flow can prevent dirt from adhering to the inclined surface 43b. The nozzle 53 may or may not protrude upward from the inclined surface 43b.

As shown in Figure 8, when viewed from above, the gap between the circular table cover 60 and the side panel 42 is narrowest at the boundary between adjacent rooms (e.g. B1 and B2, or B0 and B3). Grinding debris easily becomes clogged in this narrow gap.

Even if the table cover 60 is not provided, the gap between the table 10 and the side panel 42 is narrowest at the boundary between adjacent rooms when viewed from above. This narrow gap is prone to becoming clogged with grinding debris.

Therefore, in this embodiment, the return opening 42c of the side panel 42 is disposed near the boundary between adjacent rooms (e.g., B1 and B2, or B0 and B3), and disposed near the fixed partition wall 45. Near the fixed partition wall 45 means, for example, within a range of 50 mm from the fixed partition wall 45. It is sufficient that at least a part of the return opening 42c is within that range.

The return port 42c of the side panel 42 is located near the boundary between adjacent rooms (e.g., B1 and B2, or B0 and B3) to supply cleaning liquid to the gap between the table cover 60, etc. and the side panel 42, forming a liquid flow. This flow prevents grinding debris from clogging the gap.

As shown in FIG. 9(B), when viewed from the front of the side panel 42, the outlet 53a of the nozzle 53 may be positioned as close as possible to the boundary between the adjacent rooms, that is, as close as possible to the fixed partition wall 45.

For example, when viewed from the front of the side panel 42, the distance between the fixed partition wall 45 and the outlet 53a of the nozzle 53 may be approximately the same as the distance between the fixed partition wall 45 and the return port 42c. The cleaning liquid can be supplied to the inside of the housing 40 from the end of the return port 42c closest to the fixed partition wall 45.

Although not shown, the liquid receiving portion 42a of the side panel 42 may be provided with a nozzle for supplying cleaning liquid to the inside of the housing 40. This nozzle is provided, for example, on the upper part of the liquid receiving portion 42a. After being discharged from the nozzle, the cleaning liquid flows down the liquid receiving portion 42a, washing away grinding debris adhering to the liquid receiving portion 42a.

8 and 10, the housing 40 is located below the multiple chucks 20 and includes a pan 46 that receives the falling grinding fluid and grinding debris. The pan 46 also receives cleaning fluid. Hereinafter, the grinding fluid and cleaning fluid are collectively referred to as liquid. In addition, liquid contaminated with grinding debris is also referred to as dirty liquid. The pan 46 has two inclined surfaces 210, 220 on its upper surface.

As shown in Fig. 10(A), the two inclined surfaces 210, 220 are combined in a mountain shape, and the further away from the boundary line BL between the two adjacent rooms B0, B1 and the remaining two rooms B2, B3, the more downwardly they slope. The two inclined surfaces 210, 220 allow wastewater to flow down on both sides of the boundary line BL.

According to this embodiment, two inclined surfaces 210, 220 are combined in a mountain shape. Therefore, compared to the case where only one inclined surface is provided, if the height difference of the inclined surface is the same, the horizontal distance of the inclined surface is shorter and the gradient of the inclination is steeper. Therefore, the dirty liquid is more likely to flow down. Therefore, the flow of grinding chips and grinding fluid in the pan 46 can be improved.

As shown in FIG. 10A, the pan 46 has two gutters 230, 240 along the lower edges 211, 221 of the two inclined surfaces 210, 220. The waste liquid flows down along the two inclined surfaces 210, 220 and then enters the two gutters 230, 240.

As shown in Figures 10B and 10C, each gutter 230, 240 has a guide surface 231, 241 at the bottom of the groove that slopes downward from one end of the lower edge 211, 221 to the other end. The guide surfaces 231, 241 allow waste liquid to be collected.

10B, the gutter 230 has a guide surface 231 at its bottom that slopes downward from the loading/unloading chamber B0 toward the primary grinding chamber B1. The slope of the guide surface 231 prevents primary grinding chips contained in the dirty liquid from entering the loading/unloading chamber B0 from the primary grinding chamber B1, thereby keeping the loading/unloading chamber B0 clean.

10B, the groove 230 may have a guide surface 232 at its bottom, which is inclined in the opposite direction to the guide surface 231. The guide surface 232 is shorter than the guide surface 231 and is located at the end of the primary grinding chamber B1 opposite the load/unload chamber B0.

10(C), the groove 240 has a guide surface 241 at its bottom that slopes downward from the tertiary grinding chamber B3 toward the secondary grinding chamber B2. The slope of the guide surface 241 prevents large-grain secondary grinding chips from entering the tertiary grinding chamber B3 from the secondary grinding chamber B2, and prevents roughness of the grinding surface after tertiary grinding.

10(C), the groove 240 may have a guide surface 242 at its bottom, which is inclined in the opposite direction to the guide surface 241. The guide surface 242 is shorter than the guide surface 241 and is located at the end of the secondary grinding chamber B2 opposite the tertiary grinding chamber B3.

Each gutter 230, 240 includes an outlet 233, 243 for discharging wastewater at the lowest part of the bottom of the gutter. Pipes 250, 260 extending downward from the outlet 233, 243 are connected to the outlet 233, 243.

The waste liquid flows down along the guide surfaces 231, 241 and is discharged from the discharge outlets 233, 243 into the pipes 250, 260. The discharge outlets 233, 243 are located at the lowest points, so that the collected waste liquid can be efficiently discharged.

11, the tool driving unit 30 includes a movable unit 31 to which the grinding tool D is attached, and a lifting unit 35 that raises and lowers the movable unit 31. The lifting unit 35 faces the mountain-shaped inclined edges 212, 222 of the inclined surfaces 210, 220, rather than the lower edges 211, 221 of the inclined surfaces 210, 220. Since the lifting unit 35 does not face the gutters 230, 240, maintenance of the gutters 230, 240 is easy.

As described above, grinding fluid and cleaning fluid are supplied to the inside of the housing 40. Together with these fluids, grinding debris flows into the outlets 233 and 243. As a result, the outlets 233 and 243 may become clogged.

12, the grinding device 1 is provided with first liquid level sensors 80-1, 80-2 located inside the housing 40. The first liquid level sensors 80-1, 80-2 detect the liquid level of the liquid accumulated inside the housing 40. When the detected liquid level exceeds a preset height, the control unit 16 determines that the outlets 233, 243 are clogged.

The grinding apparatus 1 also includes sensor covers 81-1, 81-2 positioned between the chuck 20 and the first liquid level sensors 80-1, 80-2. The sensor covers 81-1, 81-2 block contaminated liquid traveling from the substrate W held by the chuck 20 to the first liquid level sensors 80-1, 80-2. This prevents contaminants from adhering to the first liquid level sensors 80-1, 80-2, and prevents malfunctions of the first liquid level sensors 80-1, 80-2. Furthermore, the impacts applied to the first liquid level sensors 80-1, 80-2 can be reduced, and failures of the first liquid level sensors 80-1, 80-2 can be prevented.

The housing 40 includes four side panels 42-1, 42-2, 42-3, and 42-4 located on either side of the chuck 20. These side panels 42 are combined into a rectangle to form four corners CR0 to CR3. CR0 is a corner of the loading/unloading chamber B0, CR1 is a corner of the primary grinding chamber B1, CR2 is a corner of the secondary grinding chamber B2, and CR3 is a corner of the tertiary grinding chamber C3.

A first liquid level sensor 80-1 is located at corner CR1, and another first liquid level sensor 80-2 is located at another corner CR2. By arranging the first liquid level sensors 80-1 and 80-2 at corners CR1 and CR2, interference with other components can be prevented.

When viewed from above, the sensor cover 81-1 has an inclined plate 81a-1 that is inclined toward each of the two side panels 42-1, 42-2 that form the corner CR1. The first liquid level sensor 80-1 is located in the space surrounded by the two side panels 42-1, 42-2 and the inclined plate 81a-1. By hiding the corner CR1 with the inclined plate 81a-1, it is possible to prevent dirt from accumulating at the corner CR1.

When viewed from above, the sensor cover 81-2 has an inclined plate 81a-2 that is inclined toward each of the two side panels 42-2, 42-3 that form the corner CR2. The first liquid level sensor 80-2 is located in the space surrounded by the two side panels 42-2, 42-3 and the inclined plate 81a-2. By hiding the corner CR2 with the inclined plate 81a-2, it is possible to prevent dirt from accumulating at the corner CR2.

When viewed from above, a first liquid level sensor 80-1 overlaps with the gutter 230, and another first liquid level sensor 80-2 overlaps with another gutter 240. The first liquid level sensors 80-1, 80-2 may be embedded inside the gutter 230, 240, or may be positioned above the gutter 230, 240. In either case, the liquid level can be detected at the position of the gutter 230, 240 where the liquid collects.

When viewed from above, the first liquid level sensors 80-1, 80-2 are located near the drain ports 233, 243. By arranging the first liquid level sensors 80-1, 80-2 near the drain ports 233, 243, clogging of the drain ports 233, 243 can be reliably detected. The vicinity of the drain ports 233, 243 is, for example, within a range of 50 mm from the drain ports 233, 243.

The grinding device 1 is provided with second liquid level sensors 82-1 and 82-2 that detect the liquid level of the liquid accumulated inside the housing 40, in addition to the first liquid level sensors 80-1 and 80-2. The first liquid level sensor 80-1 and the second liquid level sensor 82-1 are arranged at the same corner CR1 and detect the same liquid level. The first liquid level sensor 80-2 and the second liquid level sensor 82-2 are arranged at the same corner CR2 and detect the same liquid level. The same liquid level can be double-checked by the two sensors. Even if one sensor malfunctions or breaks down, the remaining sensor can detect the liquid level. The second liquid level sensors 82-1 and 82-2 may detect the liquid level at a position higher than the detection range of the first liquid level sensors 80-1 and 80-2.

Next, a pair of a first liquid level sensor 80-1 and a second liquid level sensor 82-1 will be described with reference to Figure 13. Note that another pair of a first liquid level sensor 80-2 and a second liquid level sensor 82-2 is configured in the same way, so a description thereof will be omitted.

The grinding device 1 is provided with a vertical pipe 83 outside the housing 40 that communicates with the inside of the housing 40. A horizontal pipe 86 extending from the lower end of the vertical pipe 83 is inserted into, for example, the inside of the gutter 230. A horizontal pipe 87 extending from the upper end of the vertical pipe 83 is disposed, for example, above the top panel 41 of the housing 40.

Outside air enters the interior of the vertical pipe 83. Therefore, the liquid level of the liquid in the vertical pipe 83 becomes the same as the liquid level of the liquid in the housing 40. The second liquid level sensor 82-1 is attached to the vertical pipe 83 and detects the liquid level of the liquid in the vertical pipe 83.

Unlike the first liquid level sensor 80-1, the second liquid level sensor 82-1 is disposed outside the housing 40. This prevents dirty liquid from splashing onto the second liquid level sensor 82-1, and prevents malfunction and failure of the second liquid level sensor 82-1.

The first liquid level sensor 80-1 includes a displacement meter that measures the displacement of the liquid level. For example, the first liquid level sensor 80-1 has a float 80a that rises and falls in accordance with fluctuations in the liquid level, a guide 80b for the float 80a, and a displacement meter 80c that measures the displacement of the float 80a. Note that the displacement meter is not limited to the float type. The displacement meter continuously measures the height of the liquid level within a predetermined range.

On the other hand, the second liquid level sensor 82-1 includes a switch that detects when the liquid level reaches a set value. The switch is, for example, a proximity switch. The type of proximity switch is not particularly limited, but may be, for example, an optical type. An optical proximity switch detects light transmitted through the transparent vertical tube 83 and detects when the liquid level reaches the set value from a change in the amount of light. The proximity switch may be of a capacitance type, for example. In this case, the vertical tube 83 may be opaque. By using a type different from that of the first liquid level sensor 80-1 as the second liquid level sensor 82-1, it is possible to avoid simultaneous malfunction or failure of the two sensors.

The switch of the second liquid level sensor 82-1 includes a switch that detects when the liquid level reaches a set value. The set value of the liquid level may be lower than the height H of the crest 201 (see FIG. 10A) of the two inclined surfaces 210, 220 that are combined to form a mountain shape. Clogging of the discharge ports 233, 243 can be detected before the flow along the inclined surfaces 210, 220 disappears and grinding debris begins to settle.

As shown in FIG. 12, the grinding device 1 may have a corner cover 84 that covers corner CR3, in addition to the sensor covers 81-1 and 81-2. The corner cover 84 has an inclined plate 84a that is inclined toward each of the two side panels 42-3 and 42-4 that form corner CR3. Hiding corner CR3 with the inclined plate 84a can prevent dirt from accumulating at corner CR3. The corner cover 84 does not need to be installed in the loading/unloading chamber B0.

The grinding device 1 may also have a second corner cover 85 that covers the corner between the side panel 42 and the fixed partition wall 45. The second corner cover 85 has a second inclined plate 85a that is inclined with respect to each of the side panel 42 and the fixed partition wall 45. By hiding the corner with the second inclined plate 85a, it is possible to prevent dirt from accumulating in the corner. The second corner cover 85 is installed in the primary grinding chamber B1, the secondary grinding chamber B2, and the tertiary grinding chamber B3. The second corner cover 85 does not have to be installed in the loading/unloading chamber B0.

As shown in FIG. 14(A), the grinding device 1 has an exterior 300 that forms the outer surface of the grinding device 1. The exterior 300 houses therein a table 10, a chuck 20, a chuck driving unit 19, a tool driving unit 30, a housing 40, and a collection unit 320. The collection unit 320 collects the grinding chips. The grinding chips flow into the collection unit 320 together with a liquid such as a grinding fluid. The collection unit 320 separates the liquid from the grinding chips, discharges the liquid, and leaves the grinding chips. Details of the collection unit 320 will be described later.

The exterior 300 is formed with a first opening 301 and a second opening 302. The first opening 301 allows an operator or a work robot to access the chuck 20 or the tool driving unit 30 from outside the grinding device 1. On the other hand, the second opening 302 allows an operator or a work robot to access the recovery unit 320 from outside the grinding device 1.

The grinding device 1 includes a first door 311 that opens and closes the first opening 301, and a second door 312 that opens and closes the second opening 302 separately from the first door 311. An operator or a work robot operates the first door 311 to open and close the first opening 301. Similarly, an operator or a work robot operates the second door 312 to open and close the second opening 302.

According to this embodiment, the first opening 301 and the second opening 302 are separately formed on the outer surface of the grinding device 1. The second opening 302 is formed closer to the collection section 320 than the first opening 301. As a result, when touching the collection section 320, the worker or the working robot does not need to operate the first door 311 and does not need to open the first opening 301. Therefore, the worker or the working robot does not need to touch the chuck 20 or the tool driving section 30. Therefore, the grinding chips can be taken out of the grinding device 1 without interrupting the grinding of the substrate W while driving the chuck 20 and the grinding tool D. In other words, the grinding chips can be taken out of the grinding device 1 while the substrate W is being ground.

The first opening 301 and the second opening 302 are formed, for example, on a side surface of the grinding device 1 facing the same direction. The first opening 301 and the second opening 302 may also be formed on the opposite side surface of the grinding device 1, and the number of the first openings 301 and the second openings 302 may be multiple. The number of the collection units 320 may also be multiple. The collection unit 320 is located below the housing 40 shown in FIG. 13 etc., and collects grinding chips that fall from the discharge ports 233, 243 of the housing 40.

14(A), the grinding device 1 includes a door sensor 321 that detects the opening of the first opening 301 by the first door 311. The door sensor 321 is, but is not limited to, a proximity switch, for example. When the door sensor 321 detects the opening of the first opening 301, it transmits a signal indicating the opening to the control unit 16 (see FIG. 1).

When the control unit 16 detects the opening of the first opening 301 by the door sensor 321 while the chuck 20 and grinding tool D are being driven, the control unit 16 stops the driving of the chuck 20 and grinding tool D. Similarly, when the control unit 16 detects the opening of the first opening 301 by the door sensor 321 while the table 10 is being driven, the control unit 16 stops the driving of the table 10. This makes it possible to prevent contact between the object being driven and the worker or the work robot.

On the other hand, even if the second door 312 opens the second opening 302 while the chuck 20 and the grinding tool D are being driven, the control unit 16 continues to drive the chuck 20 and the grinding tool D. Similarly, even if the second door 312 opens the second opening 302 while the table 10 is being driven, the control unit 16 continues to drive the table 10. There is no need to interrupt grinding of the substrate W in order to remove the grinding debris outside the grinding apparatus 1.

As described above, even if the second door 312 opens the second opening 302, the control unit 16 continues to drive the object. Therefore, a door sensor that detects the opening of the second opening 302 is not necessary.

14B, the recovery section 320 includes walls 341, 342, 343, 344, and 345 that limit access from the second opening 302 to the chuck 20 or the tool driving section 30. The walls 341, 342, 343, 344, and 345 form a box 340. The box 340 is open toward the second opening 302.

15, a grinding chip inlet 346 is formed in wall 341, which is the ceiling of box 340. Inlet 346 communicates with exhaust outlet 233 or 243 of housing 40 via piping 250 or 260. Inlet 346 may also communicate with both exhaust outlets 233, 243 via both piping 250, 260. Grinding chips pass through inlet 346 of box 340 and fall into the interior of box 340.

The collection section 320 may include a pair of guide walls 351, 352 inside the box 340 that guide grinding chips falling from the entrance 346 of the box 340.

As shown in FIG. 15, the collection section 320 includes multiple containers 331, 332 for storing grinding debris. The multiple containers 331, 332 can be removed separately from inside the box 340. For example, while grinding debris is being collected in one container 331, another container 332 can be removed and emptied. However, the number of containers may be just one.

As shown in Fig. 14 (B), box 340 has doors 347, 348 that open and close the removal openings for containers 331, 332. Doors 347, 348 are separate doors from second door 312, but may also serve as second door 312. A worker or a working robot opens doors 347, 348 and removes containers 331, 332 from box 340. Thereafter, the worker or the working robot returns empty containers 331, 332 to inside box 340 and closes doors 347, 348.

As shown in FIG. 15, the collection section 320 includes a switching mechanism 360 that switches the storage destination of the grinding chips. The switching mechanism 360 has, for example, a rotating plate 361 and an operating lever 362. The rotating plate 361 is located in the path through which the grinding chips fall and is inclined. The operating lever 362 rotates the rotating plate 361 and switches the inclination direction of the rotating plate 361. By switching the inclination direction of the rotating plate 361, the storage destination of the grinding chips can be switched.

The rotation diameter of the rotating plate 361 is larger than the distance between the pair of guide walls 351, 352. A pair of guide walls 351, 352 are provided within the rotation range of the rotating plate 361. The pair of guide walls 351, 352 also serve as stoppers that stop the rotation of the rotating plate 361. The rotation axis 363 of the rotating plate 361 is disposed horizontally and is located directly below the horizontal center of the pair of guide walls 351, 352.

As shown in Fig. 15 (A), when the rotating plate 361 hits the right guide wall 352, it tilts downward to the left and drops the grinding chips into the left container 331. In this case, the grinding chips are stored in the left container 331.

On the other hand, as shown in Fig. 15 (B), the rotating plate 361 hits the left guide wall 351 and tilts downward to the right, causing the grinding chips to fall into the right container 332. In this case, the grinding chips are stored in the right container 332.

The recovery section 320 includes a locking mechanism 370. The locking mechanism 370 restricts removal of the container 331 that stores the grinding chips, and allows removal of the other container 332. Alternatively, the locking mechanism 370 restricts removal of the container 332 that stores the grinding chips, and allows removal of the other container 331. This can prevent the container that stores the grinding chips from being accidentally removed while the grinding chips are being stored, and can prevent the grinding chips from scattering inside the box 340.

For example, the operating lever 362 of the switching mechanism 360 is used as the locking mechanism 370. The operating lever 362 extends, for example, in a straight line from the rotating shaft 363 of the rotating plate 361 to the path along which the container passes, and restricts the removal of the container. For example, the operating lever 362 restricts the removal of the container 331 by pressing the door 347 as shown in FIG. 14B. The operating lever 362 also restricts the removal of another container 332 by pressing another door 348. The operating lever 362 switches between a state in which only the door 347 is pressed and a state in which only the other door 348 is pressed. If the operating lever 362 is the locking mechanism 370, the locking destination can be switched at the same time as the storage destination is switched, and forgetting to switch the locking destination can be prevented.

The containers 331 and 332 include a mesh to separate the liquid from the grinding debris while leaving the grinding debris. The containers 331 and 332 are mesh cages in their entirety, but only the bottom wall may be made of mesh. The collection unit 320 includes a mesh-like mounting part 333 that supports the containers 331 and 332 from below and drops the liquid downward. A partition plate 334 may be provided on the mounting part 333 to separate the adjacent containers 331 and 332. After dripping from the containers 331 and 332, the liquid passes through the mounting part 333 and is discharged to the outside of the collection unit 320. Only the grinding debris can be left inside the collection unit 320, and the frequency of removing the containers 331 and 332 from the box 340 can be reduced.

The above describes the grinding device and grinding method according to the present disclosure, but the present disclosure is not limited to the above-described embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. Naturally, these also fall within the technical scope of the present disclosure.

For example, the number of tool driving units 30 may be one or more. The number of chucks 20 may be greater than the number of tool driving units 30. The interior of the housing 40 is divided into four rooms B0 to B3 by fixed partition walls 45, but the number of rooms is not limited to four and may be two or more.

This application claims priority based on Patent Application No. 2020-161265, filed with the Japan Patent Office on September 25, 2020, and the entire contents of Patent Application No. 2020-161265 are incorporated herein by reference.

1 Grinding device 10 Table 20 Chuck 30 Tool driving unit 51 Nozzle 60 Table cover 61 Inclined unit W Substrate

Claims (14)

A plurality of chucks for holding the substrate;
a tool driving unit that drives a grinding tool pressed against the substrate;
a table that holds a plurality of the chucks around a rotation center line and rotates around the rotation center line;
a table cover that rotates with the table;
the table cover includes an inclined portion that is inclined downward as it goes away from the rotation center line,
The grinding apparatus further comprises a nozzle disposed between the top of the ramp and the chuck for supplying a cleaning fluid to the ramp. The grinding device of claim 1, wherein the nozzle supplies the cleaning liquid to the inclined portion at a position where the cleaning liquid reaches the top of the inclined portion. A grinding device as described in claim 1 or 2, wherein the nozzle supply ports are provided in a plurality of locations spaced apart in the circumferential direction of the table cover. A grinding device as described in any one of claims 1 to 3, wherein the nozzle supply port is an arc-shaped or linear slit along the circumferential direction of the table cover. A measuring device for measuring the thickness of the substrate,
The grinding apparatus according to any one of claims 1 to 4, wherein the measuring device includes the nozzle. The grinding apparatus of claim 5, wherein the measuring device includes a first height sensor that measures the height of the substrate and a second height sensor that measures the height of the chuck. the measuring device includes a first arm that holds the first height sensor, a second arm that holds the second height sensor, and a bracket that holds the first arm and the second arm;
The grinding device according to claim 6 , wherein the nozzle is provided on a lower surface of the bracket. a fixed axis disposed on the rotation centerline of the table;
The bracket of the measuring device is attached to an upper surface of the fixed shaft and protrudes radially outward from the fixed shaft,
8. The grinding device according to claim 7, wherein the nozzle is provided on a portion of the lower surface of the bracket that protrudes radially outward from the fixed shaft. a fixed axis disposed on the rotation centerline of the table;
5. The grinding device according to claim 1, wherein the nozzle is attached to an upper surface of the fixed shaft and protrudes radially outward from the fixed shaft. the inclined portion has an opening at its top through which the fixed shaft passes;
the table cover has a central tubular portion rising from an opening edge of the opening of the inclined portion,
The grinding device according to claim 8 or 9, wherein the nozzle is disposed radially outward of the central cylindrical portion. A grinding device as described in any one of claims 1 to 10, including a second nozzle that supplies cleaning liquid from above to the bottom of the inclined portion of the table cover. a housing that houses a plurality of the chucks; and a fixed partition wall that divides an interior of the housing into a plurality of rooms around the rotation center line of the table,
The plurality of rooms include a grinding chamber in which grinding of the substrate is performed, and a loading/unloading chamber in which loading and unloading of the substrate is performed,
The grinding apparatus according to claim 11 , wherein the second nozzle is located near a boundary between the grinding chamber and the load/unload chamber. When viewed from above, one of the clockwise and counterclockwise directions is defined as a first direction, and the remaining direction is defined as a second direction. The inside of the housing is partitioned in the first direction into the loading/unloading chamber, a primary grinding chamber in which a primary grinding of the substrate is performed, a secondary grinding chamber in which a secondary grinding of the substrate is performed after the primary grinding, and a tertiary grinding chamber in which a tertiary grinding of the substrate is performed after the secondary grinding, in that order;
the second nozzle is located both near a boundary between the first grinding chamber and the loading/unloading chamber and near a boundary between the third grinding chamber and the loading/unloading chamber,
13. The grinding apparatus according to claim 12, further comprising a control unit that supplies cleaning liquid from above to the bottom portion from the second nozzle arranged in the tertiary grinding chamber when the table is rotated in the first direction, and that supplies cleaning liquid from above to the bottom portion from the second nozzle arranged in the primary grinding chamber when the table is rotated in the second direction. A grinding method for grinding a substrate using a grinding apparatus comprising: a plurality of chucks for holding a substrate; a table for holding the plurality of chucks around a rotation center line and rotating around the rotation center line; and a table cover for rotating together with the table, the table cover including an inclined portion that is inclined downward as it becomes farther from the rotation center line, the method comprising:
The method includes supplying a cleaning liquid to the inclined portion between a top of the inclined portion and the chuck while grinding the substrate.

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