Dressing device

Abstract

To provide a dressing device enabling improvement of flatness of a polishing pad and enabling uniformization of shaving quantity of the polishing pad when dressing.SOLUTION: A dressing device 1 is provided, comprising a dresser 3 dressing a polishing pad 11a which is mounted to an upper surface plate 11 and polishes a workpiece, the dresser 3 has a first dressing surface 31 opposed to the polishing pad 11a, and a first area 33 which provides prescribed dressing force and a second area 34 which provides dressing force lower than that of the first area 33 are set on the first dressing surface 31. The first area 33 and the second area 34 are juxtaposed in the surface plate circumferential direction X, and the first area 33 is arranged on one end portion 31a side in the surface plate circumferential direction. X. A compartment line 35 partitioning the first area 33 and the second area 34 has a third corner portion 35c set in a position nearer to one end portion 31a in the surface plate circumferential direction X more than a first corner portion 35a and a second corner portion 35b on both ends in the surface plate radial direction Y in an intermediate portion in the surface plate radial direction Y.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a dressing device for dressing a polishing pad attached to a surface plate of a polishing machine for polishing a workpiece.

Background Art

[0002] Conventionally, a dressing device for dressing a polishing pad attached to a surface plate for polishing a workpiece such as a silicon wafer is known. In a conventional dressing device, for example, as shown in FIGS. 13(a) and 13(b), a dresser 100 disposed between upper and lower surface plates includes a rod-shaped first grindstone 101 having a dressing surface 101a facing the upper surface plate, and a rod-shaped second grindstone 102 having a dressing surface 102a facing the lower surface plate. In the conventional dresser 100, the first and second grindstones 101 and 102 are pressed toward the upper and lower surface plates, respectively, by a coaxial cylinder 104 for pressing via an elastic member (such as a leaf spring) 103 (see, for example, Patent Document 1).

[0003] Also, in the example shown in FIGS. 13(a) and 13(b), the first grindstone 101 and the second grindstone 102 are set to the same length. However, there is also a dressing device in which the lengths of a rod-shaped first grindstone 201 and a second grindstone 202 are different, such as a dresser 200 of a modified example shown in FIGS. 14(a) and 14(b). Also in the conventional dresser 200 shown in FIGS. 14(a) and 14(b), the first grindstone 201 has a dressing surface 201a facing the upper surface plate, and the second grindstone 202 has a dressing surface 202a facing the lower surface plate. The dresser 200 presses the first grindstone 201 toward the upper surface plate with a first cylinder 204a for pressing via an elastic member (such as a leaf spring) 203, and presses the second grindstone 202 toward the lower surface plate with a second cylinder 204b for pressing.

[0004] Furthermore, conventionally, there is known a dressing device in which the dressing surface has an inner region portion located on the inner edge side of the surface plate during dressing, an outer region portion located on the outer edge side of the surface plate during dressing, and an intermediate region portion located between the inner region portion and the outer region portion (see, for example, Patent Document 2). Here, the inner region portion extends in the surface plate radial direction by a required length and is formed in a shape along the inner edge of the surface plate. The outer region portion extends in the surface plate radial direction by a required length and is formed in a shape along the outer edge of the surface plate. Furthermore, the intermediate region portion extends in the surface plate radial direction by a required length, and the length extending in the circumferential direction of the surface plate is set to be shorter than the lengths extending in the circumferential direction of the surface plate of the inner region portion and the outer region portion.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, for example, in the dressing device described in Patent Document 1, the amount of abrasion of the polishing pad is small at the outer peripheral portion and the inner peripheral portion of the surface plate, and there is a difference in the amount of abrasion of the polishing pad between the outer peripheral portion and the inner peripheral portion of the surface plate and the intermediate portion. Therefore, there is a problem that it is difficult to uniformly flatten the entire surface of the polishing pad. Further, for example, in the dressing device described in Patent Document 2, there is a tendency to over-abrade the polishing pad in the vicinity of the outer peripheral edge and the inner peripheral edge of the surface plate during dressing, and the amount of abrasion of the polishing pad greatly varies at the outer peripheral portion and the inner peripheral portion of the surface plate.

[0007] The present invention has been made paying attention to the above problems, and an object thereof is to provide a dressing device capable of improving the flatness of the polishing pad during dressing and making the amount of abrasion of the polishing pad uniform.

Means for Solving the Problem

[0008] In order to achieve the above object, the present invention provides a dressing device including a dresser for dressing a polishing pad attached to a surface plate for polishing a workpiece. The dresser has a dressing surface facing the polishing pad, and a first region having a predetermined dressing force and a second region having a lower dressing force than the first region are set on the dressing surface. The first region and the second region are arranged side by side in the circumferential direction of the surface plate, and the first region is disposed on one end side in the circumferential direction of the surface plate of the dressing surface. Further, a partition line partitioning the first region and the second region has an intermediate point set at a position closer to one end in the circumferential direction of the dressing surface than both ends in the middle part in the radial direction of the surface plate. And the dressing surface has a shape in which the dimension in the radial direction of the surface plate gradually increases from one end in the circumferential direction of the surface plate toward the other end in the circumferential direction of the surface plate. When the dresser is located at the outer peripheral edge of the surface plate, the side portion on the outer peripheral side in the radial direction of the surface plate is along the tangential direction of the outer peripheral edge of the surface plate. When the dresser is located at the inner peripheral edge of the surface plate, the side portion on the inner peripheral side in the radial direction of the surface plate is along the tangential direction of the inner peripheral edge of the surface plate. Further, the intermediate point is parallel to the tangential direction of the inner peripheral edge of the surface plate and is on the intersection of a first straight line passing through the intersection of the side portion on the outer peripheral side in the radial direction of the dressing surface and one end in the circumferential direction of the surface plate, and a second straight line parallel to the tangential direction of the outer peripheral edge of the surface plate and passing through the intersection of the side portion on the inner peripheral side in the radial direction of the dressing surface and one end in the circumferential direction of the surface plate. Also, the angle formed by the tangential direction of the outer peripheral edge of the surface plate and the partition line and the angle formed by the tangential direction of the inner peripheral edge of the surface plate and the partition line are set to the same angle. The angle formed by the tangential direction of the outer peripheral edge of the surface plate and the first straight line and the angle formed by the tangential direction of the inner peripheral edge of the surface plate and the second straight line are set to the same angle. And the contact length in the circumferential direction of the surface plate between the polishing pad and the first region gradually decreases as the dresser moves from the side portion on the outer peripheral side in the radial direction of the dressing surface toward the side portion on the inner peripheral side in the radial direction of the dressing surface when the dresser is located at the outer peripheral edge of the surface plate, and gradually decreases as the dresser moves from the side portion on the inner peripheral side in the radial direction of the dressing surface toward the side portion on the outer peripheral side in the radial direction of the dressing surface when the dresser is located at the inner peripheral edge of the surface plate. It is characterized by this.

Effect of the Invention

[0009] In the dressing device of the present invention, it is possible to improve the flatness of the polishing pad during dressing and make the amount of shaving of the polishing pad uniform.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

MODE FOR CARRYING OUT THE INVENTION

[0011] Hereinafter, a mode for carrying out the dressing device of the present invention will be described based on Example 1 shown in the drawings.

[0012] The dressing device 1 of Example 1 is a dressing device for a double-sided polishing machine that simultaneously dresses a polishing pad 11a attached to the upper platen 11 of a double-sided polishing machine 10 that polishes both the front and back surfaces of a thin plate-shaped workpiece, and a polishing pad 12a attached to the lower platen 12 of the double-sided polishing machine 10. Note that dressing means grinding or roughening the surfaces of the polishing pads 11a and 12a to restore the slurry retention of the polishing pads 11a and 12a and maintain the polishing ability of the double-sided polishing machine 10. The surfaces of the polishing pads 11a and 12a are preferably uniformly flattened by dressing or the amount of material removed from the polishing pads is made uniform.

[0013] During dressing, the dressing device 1 inserts a dresser 3 between the upper and lower platens 11 and 12. Further, the double-sided polishing machine 10 rotates the upper platen 11 in a first direction (for example, counterclockwise, hereinafter referred to as the "upper platen rotation direction CCW") by a rotating shaft 13 with the dresser 3 sandwiched between the upper platen 11 and the lower platen 12, and rotates the lower platen 12 in a second direction opposite to the first direction (for example, clockwise, hereinafter referred to as the "lower platen rotation direction CW"). Thereby, the polishing pads 11a and 12a are in sliding contact with the dresser 3, and the polishing pads 11a and 12a are dressed. Further, both the upper platen 11 and the lower platen 12 have a donut disk shape with a rotating shaft 13 attached to the center, and during dressing, the dresser 3 moves between the outer peripheral edge 14 and the inner peripheral edge 15 of the upper and lower platens 11 and 12.

[0014] As shown in FIGS. 1 and 2, the dressing device 1 includes an arm member 2, a dresser 3 provided at the tip 2b of the arm member 2, a drive mechanism 4 that rotates the arm member 2, and a control unit (not shown) that controls the drive mechanism 4.

[0015] The arm member 2 has a base portion 2a held by a drive mechanism 4 disposed in the vicinity of the double-sided polishing machine 10, and is a pipe member extending horizontally from the drive mechanism 4. The arm member 2 rotates about the base portion 2a by the drive mechanism 4, and the tip portion 2b is advanced and retracted between the upper and lower surface plates 11 and 12. That is, the tip portion 2b of the arm member 2 moves along an arc-shaped orbit 2c centered on the base portion 2a as shown in FIG. 2. Then, the arm member 2 is rotated between the upper and lower surface plates 11 and 12 during dressing, and the dresser 3 is moved along the orbit 2c. Further, the arm member 2 is rotated to a position where the dresser 3 is retracted from between the upper and lower surface plates 11 and 12 except during dressing.

[0016] The dresser 3 has a dressing member 3a and a washing water injection mechanism 3b. The dressing member 3a has a function of dressing the polishing pads 11a and 12a. The dressing member 3a has a flat first dressing surface 31 (see FIG. 3) facing the upper surface plate 11 during dressing and a flat second dressing surface 32 (see FIG. 4) facing the lower surface plate 12 during dressing. Abrasive grains are electrodeposited on the first dressing surface 31 and the second dressing surface 32, respectively, and the mesh number of the particle size is arbitrarily set. As the abrasive grains electrodeposited on the first dressing surface 31 and the second dressing surface 32, diamond, CBN abrasive grains, etc. can be used. Note that the plurality of circular holes 3c provided in the first dressing surface 31 and the second dressing surface 32 shown in FIGS. 3 and 4 are screw holes formed arbitrarily.

[0017] The cleaning water injection mechanism 3b has a function of injecting high-pressure cleaning water during dressing. The cleaning water injection mechanism 3b includes a pair of first injection ports 38 (see FIG. 3) provided on the side of the first dressing surface 31, three second injection ports 39 (see FIG. 4) provided on the side of the second dressing surface 32, and a cleaning water passage (not shown) that penetrates the dressing member 3a and communicates with the first injection port 38 and the second injection port 39. The cleaning water is supplied through the inside of the arm member 2. Here, the first injection port 38 is located upstream in the counterclockwise (CCW) direction of the upper platen rotation direction from the first dressing surface 31. Also, the second injection port 39 is located upstream in the clockwise (CW) direction of the lower platen rotation direction from the second dressing surface 32. Further, both the first and second injection ports 38 and 39 are set at a height that does not contact the polishing pads 11a and 12a during dressing.

[0018] As shown in FIG. 5, the first dressing surface 31 has a shape in which the dimension W in the platen radial direction Y (a direction orthogonal to the platen circumferential direction X; see FIGS. 2 to 5), which is the radial direction of the upper and lower platens 11 and 12, gradually increases from one end 31a in the platen circumferential direction X (see FIGS. 2 to 5), which is the circumferential direction of the upper and lower platens 11 and 12, toward the other end 31b in the platen circumferential direction X. As a result, as shown in FIG. 2, when the dresser 3 is located at the outer peripheral edge 14 of the upper and lower platens 11 and 12 during dressing, one side portion 31c (the outer peripheral side portion) of the first dressing surface 31 in the platen radial direction Y is along the tangent direction Lα of the outer peripheral edge 14. Also, when the dresser 3 is located at the inner peripheral edge 15 of the upper and lower platens 11 and 12 during dressing, the other side portion 31d (the inner peripheral side portion) of the first dressing surface 31 in the platen radial direction Y is along the tangent direction Lβ of the inner peripheral edge 15. Further, both ends 31a and 31b of the first dressing surface 31 in the platen circumferential direction X extend substantially parallel. For this reason, the first dressing surface 31 has a substantially trapezoidal shape in plan view.

[0019] Here, "when the dresser 3 is located at the outer peripheral edges 14 of the upper and lower platens 11 and 12" means that the dresser 3 has moved to the outermost periphery of the upper and lower platens 11 and 12. Also, "when the dresser 3 is located at the inner peripheral edges 15 of the upper and lower platens 11 and 12" means that the dresser 3 has moved to the innermost periphery of the upper and lower platens 11 and 12.

[0020] In addition, the first dressing surface 31 is subjected to large R processing at both one end 31a in the platen circumferential direction X and the other end 31b in the platen circumferential direction X in order to reduce the contact force with the polishing pad 11a.

[0021] Also, a first region 33 and a second region 34 are set on the first dressing surface 31. In the first region 33, abrasive grains with a relatively large particle size are electrodeposited, and it is set to a relatively low mesh size (coarse grain size) such as #50 to 325. In the second region 34, abrasive grains with a smaller particle size than that in the first region 33 are electrodeposited, and it is set to a higher mesh size (finer grain size) than that in the first region 33, such as #325 to 3000. As shown in FIG. 6, the first region 33 and the second region 34 are set flush. That is, the distance from the first region 33 to the polishing pad 11a is the same as the distance from the second region 34 to the polishing pad 11a.

[0022] The first region 33 and the second region 34 are arranged side by side along the platen circumferential direction X. Here, the first region 33 is arranged on the side of one end 31a in the platen circumferential direction X, and the second region 34 is arranged on the side of the other end 31b in the platen circumferential direction X. The first region 33 and the second region 34 are partitioned by a partition line 35.

[0023] As shown in FIG. 5, the partition line 35 is constituted by a straight line connecting the first corner portion 35a, the second corner portion 35b, and the third corner portion 35c (midpoint). Here, the first corner portion 35a is a point set on one side portion 31c in the chuck diameter direction Y of the first dressing surface 31. The second corner portion 35b is a point set on the other side portion 31d in the chuck diameter direction Y of the first dressing surface 31. The third corner portion 35c is a point set in the middle portion in the chuck diameter direction Y of the first dressing surface 31. And the third corner portion 35c is set at a position closer to one end portion 31a in the chuck circumferential direction X of the first dressing surface 31 than the first and second corner portions 35a and 35b located on both side portions 31c and 31d in the chuck diameter direction Y.

[0024] Thereby, at the boundary position between the first region 33 and the second region 34, pointed portions 36 are respectively formed at both end portions in the chuck diameter direction Y. And the second region 34 is located between the two pointed portions 36.

[0025] In addition, in the first embodiment, R processing is performed on the pointed portions 36. Therefore, in the first embodiment, the first corner portion 35a and the second corner portion 35b are set on straight lines along the respective side portions 31c and 31d, that is, on both side portions 31c and 31d in the virtual chuck diameter direction Y when it is assumed that R processing is not performed on the pointed portions 36.

[0026] Further, as schematically shown in FIG. 7, the third corner portion 35c is set at the intersection of a first straight line L1 and a second straight line L2 set on the first dressing surface 31. Here, the first straight line L1 is parallel to the tangential direction Lβ of the inner peripheral edge 15 of the upper and lower chucks 11 and 12 and is a straight line passing through the fourth corner portion 35d set on the first dressing surface 31. The fourth corner portion 35d is the intersection of one side portion 31c in the chuck diameter direction Y of the first dressing surface 31 and one end portion 31a in the chuck circumferential direction X. Also, the second straight line L2 is parallel to the tangential direction Lα of the outer peripheral edge 14 of the upper and lower chucks 11 and 12 and is a straight line passing through the fifth corner portion 35e set on the first dressing surface 31. The fifth corner portion 35e is the intersection of the other side portion 31d in the chuck diameter direction Y of the first dressing surface 31 and one end portion 31a in the chuck circumferential direction X.

[0027] Furthermore, in the first region 33, the angle θ1 formed by the tangential direction Lα and the partition line 35 (the interior angle of the first corner portion 35a) and the angle θ2 formed by the tangential direction Lβ and the partition line 35 (the interior angle of the second corner portion 35b) are set to the same angle. Also, the angle θ3 formed by the tangential direction Lα and the first straight line L1 and the angle θ4 formed by the tangential direction Lβ and the second straight line L2 are set to the same angle.

[0028] In addition, in the first embodiment, the angle θ5 formed by the tangential direction Lα of the outer peripheral edge 14 and the tangential direction Lβ of the inner peripheral edge 15 is also set to the same angle as the angles θ3 and θ4. The angle θ5 is set according to the length of the arm member 2 or the radius of the upper and lower surface plates 11 and 12, and is set to an angle greater than zero degrees and up to about 100 degrees, for example.

[0029] Then, by setting the third corner portion 35c on the intersection of the first straight line L1 and the second straight line L2 and setting θ1 and θ2, θ3 and θ4 to the same angles respectively, when the dresser 3 is located on the outer peripheral edge 14 of the upper and lower surface plates 11 and 12, as shown in FIG. 8, the circumferential contact length of the first region 33 and the polishing pad 11a in the surface plate circumferential direction gradually decreases from one side portion 31c in the surface plate radial direction Y of the first dressing surface 31 (the side portion on the outer peripheral edge 14 side of the upper and lower surface plates 11 and 12) toward the other side portion 31d in the surface plate radial direction Y (the side portion on the inner peripheral edge 15 side of the upper and lower surface plates 11 and 12). Note that the circumferential contact length shown in FIG. 8 does not consider the holes 3c.

[0030] Furthermore, in FIG. 8, the region (the hatched region) surrounded by the X-axis, the Y-axis, and the line indicating the circumferential contact length of the first region 33 and the polishing pad 11a represents the contact area between the first region 33 and the polishing pad 11a. When the dresser 3 is located on the outer peripheral edge 14 of the upper and lower surface plates 11 and 12, the contact area between the first region 33 and the polishing pad 11a gradually decreases from the outermost periphery of the upper and lower surface plates 11 and 12 as can be seen from FIG. 8, and substantially forms a triangular shape when illustrated with the horizontal axis as the surface plate radial direction Y.

[0031] Also, when the dresser 3 is located at the inner peripheral edges 15 of the upper and lower platens 11 and 12, although not shown, the contact length in the platen circumferential direction X between the first region 33 and the polishing pad 11a gradually decreases from the other side portion 31d in the platen radial direction Y of the first dressing surface 31 (the side portion on the inner peripheral edge 15 side of the upper and lower platens 11 and 12) toward the one side portion 31c in the platen radial direction Y (the side portion on the outer peripheral edge 14 side of the upper and lower platens 11 and 12).

[0032] That is, the contact length in the platen circumferential direction X between the first region 33 and the polishing pad 11a gradually decreases from the platen edge portion (outer peripheral edge 14 or inner peripheral edge 15) side toward the platen inner portion (the intermediate portion in the platen radial direction Y of the upper and lower platens 11 and 12) both when the dresser 3 is located at the outer peripheral edge 14 of the upper and lower platens 11 and 12 and when the dresser 3 is located at the inner peripheral edge 15 of the upper and lower platens 11 and 12.

[0033] Also, θ1, θ2, θ3, and θ4 may be set to the same angle. In that case, when the dresser 3 is located at the outer peripheral edge 14 of the upper and lower platens 11 and 12, the contact length in the platen circumferential direction X between the first region 33 and the polishing pad 11a decreases at a constant reduction rate or gradually decreases from the one side portion 31c in the platen radial direction Y of the first dressing surface 31 (the side portion on the outer peripheral edge 14 side of the upper and lower platens 11 and 12) toward the other side portion 31d in the platen radial direction Y (the side portion on the inner peripheral edge 15 side of the upper and lower platens 11 and 12). Also, when the dresser 3 is located at the inner peripheral edge 15 of the upper and lower platens 11 and 12, the contact length in the platen circumferential direction X between the first region 33 and the polishing pad 11a decreases at a constant reduction rate or gradually decreases from the other side portion 31d in the platen radial direction Y of the first dressing surface 31 (the side portion on the inner peripheral edge 15 side of the upper and lower platens 11 and 12) toward the one side portion 31c in the platen radial direction Y (the side portion on the outer peripheral edge 14 side of the upper and lower platens 11 and 12).

[0034] Furthermore, a groove portion 37 is formed in the first dressing surface 31. The groove portion 37 is a depression formed in the first dressing surface 31 and is open to the side of the dresser 3. The groove portion 37 is set to a width and depth that allow a fluid such as cleaning water supplied during dressing to flow.

[0035] Further, the groove portion 37 of Example 1 has a first groove portion 37a, a second groove portion 37b, and a third groove portion 37c.

[0036] The first groove portion 37a extends along the partition line 35. The first groove portion 37a divides the first region 33 and the second region 34.

[0037] The second groove portion 37b extends along the surface plate circumferential direction X. The second groove portion 37b passes through the center position in the surface plate radial direction Y of the first dressing surface 31. Further, the second groove portion 37b is formed from one end portion 31a in the surface plate circumferential direction X to the other end portion 31b in the surface plate circumferential direction X, and is formed in the first region 33 and the second region 34.

[0038] The third groove portion 37c extends from the center position in the surface plate radial direction Y of the first dressing surface 31 toward the side portions 31c and 31d in the surface plate radial direction Y in a direction following the downstream direction with respect to the rotation of the upper surface plate 11. Note that the "direction following the downstream direction with respect to the rotation of the upper surface plate 11" is a direction in which the fluid flowing into the groove portion 37 flows to the downstream side in the upper surface plate rotation direction CCW. Further, the third groove portion 37c is formed only in the first region 33.

[0039] The second dressing surface 32 is located on the opposite side of the first dressing surface 31, and since it has the same shape as the first dressing surface 31 as shown in FIG. 4, detailed description thereof is omitted.

[0040] Also, on the second dressing surface 32, a first region 33 set to a predetermined mesh size (for example, #50 to 325, etc.) and a second region 34 set to a higher mesh size than the first region 33 (for example, #325 to 3000, etc.) are set. Since the first region 33 and the second region 34 set on the second dressing surface 32 and the first region 33 and the second region 34 set on the first dressing surface 31 have the same shape, detailed description thereof is omitted.

[0041] Furthermore, a groove portion 37 having a first groove portion 37a, a second groove portion 37b, and a third groove portion 37c is also formed on the second dressing surface 32. Here, since the shapes of the first groove portion 37a and the second groove portion 37b are the same as those of the first groove portion 37a and the second groove portion 37b formed on the first dressing surface 31, detailed description thereof is omitted.

[0042] On the other hand, the third groove portion 37c formed on the second dressing surface 32 extends from the central position in the surface plate diameter direction Y of the second dressing surface 32 toward the side portions 32c and 32d in the surface plate diameter direction Y in a direction following the downstream with respect to the rotation of the lower surface plate 12. Note that the "direction following the downstream with respect to the rotation of the lower surface plate 12" is a direction in which the fluid flowing into the groove portion 37 flows to the downstream side in the lower surface plate rotation direction CW. Here, the upper surface plate rotation direction CCW and the lower surface plate rotation direction CW are opposite to each other. Therefore, as shown in FIG. 4, the third groove portion 37c formed on the second dressing surface 32 extends in a direction different from that of the third groove portion 37c formed on the first dressing surface 31.

[0043] Hereinafter, the operation of the dressing device 1 of Example 1 will be described.

[0044] When dressing the polishing pads 11a and 12a of the double-sided polishing machine 10, the dressing device 1 of Example 1 controls each part by a control unit (not shown). First, the drive mechanism 4 rotates the arm member 2. Then, the drive mechanism 4 inserts the dresser 3 provided at the tip portion 2b of the arm member 2 between the upper surface plate 11 and the lower surface plate 12.

[0045] Next, the double-sided polishing machine 10 sets the gap height between the upper surface plate 11 and the lower surface plate 12 to a predetermined height set in advance. Thereby, the dresser 3 is sandwiched between the upper and lower surface plates 11 and 12, the first dressing surface 31 contacts the polishing pad 11a of the upper surface plate 11, and the second dressing surface 32 contacts the polishing pad 12a of the lower surface plate 12.

[0046] Then, with the first and second dressing surfaces 31 and 32 in contact with the polishing pads 11a and 12a respectively, the upper platen 11 and the lower platen 12 are rotated in opposite directions about the rotation axis 13. At this time, the dressing device 1 drives the drive mechanism 4 to further rotate the arm member 2. As a result, the dressing device 1 moves the dresser 3 from the outer peripheral edge 14 side of the upper and lower platens 11 and 12 toward the inner peripheral edge 15 side along the orbit 2c, while bringing the polishing pads 11a and 12a into sliding contact with the dresser 3 to dress the polishing pads 11a and 12a.

[0047] Here, in the dressing device 1 of the first embodiment, the first dressing surface 31 has a shape in which the dimension W in the platen radial direction Y gradually increases from one end 31a in the platen circumferential direction X toward the other end 31b in the platen circumferential direction X. And in the dressing device 1 of the first embodiment, a first region 33 having a predetermined mesh size and a second region 34 having a higher mesh size than the first region 33 are set on the first dressing surface 31. Further, the first region 33 and the second region 34 are arranged side by side in the platen circumferential direction X, and the first region 33 is disposed on the one end 31a side in the platen circumferential direction X. Furthermore, the partition line 35 partitioning the first region 33 and the second region 34 has a third corner 35c set at a position closer to the one end 31a in the platen circumferential direction X than both ends (the first corner 35a and the second corner 35b) in the platen radial direction Y in the middle of the platen radial direction Y.

[0048] As a result, since the mesh number of the first region 33 is lower (coarser) than that of the second region 34, the dressing force is higher than that of the second region 34, and the contact length in the surface plate circumferential direction X between the first region 33 and the polishing pad 11a can be gradually reduced from the surface plate edge portion (outer peripheral edge 14 or inner peripheral edge 15) side toward the surface plate inner portion (the middle portion in the surface plate radial direction Y of the upper and lower surface plates 11 and 12) regardless of whether the dresser 3 is located at the outer peripheral edge 14 of the upper and lower surface plates 11 and 12 or the dresser 3 is located at the inner peripheral edge 15 of the upper and lower surface plates 11 and 12 (see FIG. 8 for example). As a result, as shown in FIG. 9(a), the difference between the amount of wear of the polishing pad 11a at the outer peripheral portion (near the outer peripheral edge 14) and the inner peripheral portion (near the inner peripheral edge 15) of the upper surface plate 11 and the amount of wear of the polishing pad 11a at the middle portion in the radial direction of the upper surface plate 11 can be made small without overhanging the dresser 3. As a result, the dressing device 1 of Example 1 can improve the flatness of the polishing pad 11a.

[0049] In addition, in the dressing device 1 of Example 1, although the dressing force depending on the mesh number of the abrasive grains is used, the dressing force obtained depending on the density, material, arrangement, etc. of the abrasive grains may also be used. That is, the dressing device 1 varies the magnitude of the dressing force by adjusting the mesh number of the abrasive grains, but the magnitude of the dressing force may also be changed by adjusting the density, material, arrangement, etc. of the abrasive grains.

[0050] Note that "overhang" means dressing in a state where a part of the dresser 3 protrudes outside the surface plate with respect to the outer peripheral edge 14 and the inner peripheral edge 15 of the upper surface plate 11. When the dresser 3 is overhung, it becomes possible to dress the polishing pads 11a and 12a in a desired state at the outer peripheral portion and the inner peripheral portion of the upper and lower surface plates 11 and 12. However, in this case, the control is difficult, such as the position adjustment of the dresser 3 becoming complicated or interference occurring between the dresser 3 and structures such as internal gears and sun gears. Therefore, it is preferable not to overhang the dresser 3.

[0051] Further, the amount of material removed from the polishing pad 11a shown in FIG. 9(a) is a value measured along the measurement line LS shown in FIG. 9(b). Furthermore, the amount of material removed from the polishing pad 11a shown in FIG. 9(a) is the value when the movement along the orbit 2c of the dresser 3 is stopped for a predetermined time (e.g., 10 seconds) when the first dressing surface 31 contacts the outer peripheral edge 14 of the upper platen 11 and when the first dressing surface 31 contacts the inner peripheral edge 15 during dressing.

[0052] Also, for example, in the case of a dresser having a first region 33X that is rectangular in plan view as shown in FIG. 10(a), when the dresser is located at the outer peripheral edge 14 or the inner peripheral edge 15 of the upper and lower platens 11 and 12, the dressing surface contacts the outer peripheral edge 14 or the inner peripheral edge 15 obliquely due to the rotation of the arm member 2. For this reason, for example, when the dresser of the first comparative example is located at the outer peripheral edge 14 of the upper and lower platens 11 and 12, the contact length in the platen circumferential direction X between the first region 33X and the polishing pad 11a does not continue to decrease from one side portion 31c in the platen radial direction Y toward the other side portion 31d in the platen radial direction Y as shown in FIG. 10(b). Further, the contact area between the first region 33X, which is shown hatched in FIG. 10(b), and the polishing pad 11a has a trapezoidal shape when illustrated with the horizontal axis being the platen radial direction Y.

[0053] Therefore, as shown in FIG. 10(c), compared with Example 1, the amount of material removed from the polishing pad 11a is less in the outer peripheral portion and the inner peripheral portion of the upper platen 11. On the other hand, in the intermediate portion in the radial direction of the upper platen 11, the amount of material removed from the polishing pad 11a is more compared with Example 1. Therefore, the difference between the amount of material removed from the polishing pad 11a in the outer peripheral portion and the inner peripheral portion of the upper platen 11 and the amount of material removed from the polishing pad 11a in the intermediate portion of the upper platen 11 becomes larger than that in Example 1, and the flatness of the polishing pad 11a cannot be improved.

[0054] Further, for example, in the case of a dresser having a first region 33Y having a shape in which the vertices of two triangles are connected in a plan view as shown in FIG. 11(a), for example, when the dresser of the second comparative example is located on the outer peripheral edges 14 of the upper and lower platens 11 and 12, the contact length in the platen circumferential direction X between the first region 33Y and the polishing pad 11a does not gradually decrease from one side portion 31c in the platen radial direction Y toward the other side portion 31d in the platen radial direction Y as shown in FIG. 11(b), but increases midway and then decreases again. In addition, the contact area between the first region 33Y shown with hatching in FIG. 11(b) and the polishing pad 11a forms a shape in which two triangles are arranged when the horizontal axis is the platen radial direction Y and is illustrated.

[0055] Therefore, as shown in FIG. 11(c), the increase in the amount of wear of the polishing pad 11a fluctuates greatly in the outer peripheral portion and the inner peripheral portion of the upper platen 11, resulting in a so-called step D. Therefore, the flatness of the polishing pad 11a cannot be improved.

[0056] Furthermore, in the dressing device 1 of the first embodiment, a second region 34 having a higher mesh number (finer) and a lower dressing force than the first region 33 is set on the first dressing surface 31. Here, the second region 34 is arranged side by side along the platen circumferential direction X with respect to the first region 33. Thereby, the impact force acting on the edge portion of the first groove portion 37a can be suppressed, and the portion along the partition line 35, that is, the sharp portion 36, among the peripheral edges of the first region 33 can be protected.

[0057] In addition, by protecting the periphery of the sharp portion 36 with the second region 34, the exfoliation of abrasive grains at the sharp portion 36 can be suppressed. Furthermore, the polishing pad 11a can be pressed by the second region 34, making it difficult for the sharp portion 36 to get caught on the polishing pad 11a and preventing damage to the polishing pad 11a.

[0058] Also, for example, when the second region 34 is formed of a flat metal surface or the like having no dressing force, the second region 34 may crush the pores of the polishing pad 11a roughened by the first region 33. Therefore, it is not desirable to make the second region 34 a surface having no dressing force such as a metal surface. On the other hand, in the dressing device 1 of the first embodiment, by giving the second region 34 a dressing force lower than that of the first region 33, although the polishing pad 11a is not actively roughened, it is possible to prevent the pores of the polishing pad 11a roughened by the first region 33 from being crushed.

[0059] Furthermore, since the dressing force of the second region 34 only needs to be lower than that of the first region 33, in addition to abrasive grains, it may be formed of a material having a dressing force, such as a relatively soft brush, a high-count grindstone, or a surface of ceramics or the like whose surface has been roughened.

[0060] Also, in the dressing device 1 of the first embodiment, the third corner portion 35c set on the partition line 35 is set at the intersection of a first straight line L1 parallel to the tangential direction Lβ of the inner peripheral edge 15 of the upper platen 11 and a second straight line L2 parallel to the tangential direction Lα of the outer peripheral edge 14 of the upper platen 11. Furthermore, the angle θ1 formed by the tangential direction Lα and the partition line 35 and the angle θ2 formed by the tangential direction Lβ and the partition line 35 are set to the same angle, and the angle θ3 formed by the tangential direction Lα and the first straight line L1 and the angle θ4 formed by the tangential direction Lβ and the second straight line L2 are set to the same angle.

[0061] As a result, as shown in FIG. 8, the dressing device 1 of the first embodiment can gradually reduce the contact length in the platen circumferential direction X between the first region 33 and the polishing pad 11a both when the dresser 3 is located at the outer peripheral edge 14 of the upper and lower platens 11 and 12 and when the dresser 3 is located at the inner peripheral edge 15 of the upper and lower platens 11 and 12, from the platen edge portion (outer peripheral edge 14 or inner peripheral edge 15) side toward the platen inner portion (the middle portion in the platen radial direction Y of the upper and lower platens 11 and 12). As a result, as shown in FIG. 9(a), the variation in the amount of shaving of the polishing pad 11a can be suppressed between the outer peripheral portion, inner peripheral portion, and middle portion of the upper platen 11, and the flatness of the polishing pad 11a can be improved.

[0062] In addition, for example, when the angles θ1 and θ2 are set to angles significantly smaller than the angles θ3 and θ4 as in the first region 33A of the first modification example shown in FIG. 12(a), as shown in FIG. 12(b), when the dresser 3 is located at the outer peripheral edge 14 of the upper and lower surface plates 11 and 12, at an intermediate position (middle position) from the side portion 31c toward the side portion 31d, the reduction rate of the contact length in the surface plate circumferential direction X between the first region 33A and the polishing pad 11a changes significantly. Also, although not shown, when the dresser 3 is located at the inner peripheral edge 15 of the upper and lower surface plates 11 and 12, at an intermediate position (middle position) from the side portion 31d toward the side portion 31c, the reduction rate of the contact length in the surface plate circumferential direction X between the first region 33A and the polishing pad 11a changes significantly. Further, the contact area between the first region 33 shown hatched in FIG. 12(b) and the polishing pad 11a does not form a triangle when illustrated with the horizontal axis as the surface plate radial direction Y.

[0063] However, even in such a case, as shown in FIG. 12(c), it is possible to suppress fluctuations in the amount of material removed from the polishing pad 11a and improve the flatness of the polishing pad 11a between the outer peripheral portion and the inner peripheral portion of the upper surface plate 11 and the intermediate portion in the radial direction.

[0064] However, it is desirable that the shortest distance B from the straight line connecting the fourth corner portion 35d and the fifth corner portion 35e to the third corner portion 35c is 10% or more of the length of the shortest distance A from the straight line connecting the first corner portion 35a and the second corner portion 35b to the third corner portion 35c. If the distance B becomes shorter than this, the area of the first region 33A becomes narrow, and the dressing function of the dressing device 1 deteriorates and its practicality decreases.

[0065] Also, in the dressing device 1 of the first embodiment, the cleaning water (fluid) supplied during dressing can flow on the first dressing surface 31, and a groove portion 37 that is open to the side of the dresser 3 is formed.

[0066] As a result, the dressing device 1 of Example 1 can discharge grinding debris of the polishing pad 11a generated by dressing, deposits, by-products, etc. adhering to the polishing pad 11a, from between the first dressing surface 31 and the polishing pad 11a, by the cleaning water flowing through the groove portion 37.

[0067] In particular, in Example 1, the groove portion 37 has a first groove portion 37a along the partition line 35. Thereby, a gap can be opened between the first region 33 and the second region 34, and the discharge performance of grinding debris can be enhanced. For this reason, clogging of the dresser 3 can be suppressed.

[0068] Also, in Example 1, the groove portion 37 has a second groove portion 37b along the surface plate circumferential direction X. Thereby, the discharge performance of the cleaning water flowing along the surface plate circumferential direction X can be improved, and the discharge performance of grinding debris can be enhanced. For this reason, clogging of the dresser 3 can be suppressed.

[0069] Furthermore, in Example 1, the groove portion 37 has a third groove portion 37c extending in a direction following the downstream direction with respect to the rotation of the upper surface plate 11, from the center position in the surface plate radial direction Y of the first dressing surface 31 toward both side portions 31c, 31d in the surface plate radial direction Y. Thereby, the discharge performance of grinding debris can be enhanced, and clogging of the dresser 3 can be suppressed.

[0070] Furthermore, in the dressing device 1 of Example 1, the first dressing surface 31 is subjected to R processing on both the one end portion 31a in the surface plate circumferential direction X and the other end portion 31b in the surface plate circumferential direction X. Thereby, the resistance can be reduced between both end portions 31a, 31b of the first dressing surface 31 and the polishing pad 11a. For this reason, it is possible to suppress the first dressing surface 31 from being caught by the polishing pad 11a, and to suppress damage to the polishing pad 11a and abrasive grains.

[0071] In the dressing device 1 of the first embodiment, the same operational effects as those of the first dressing surface 31 can be obtained also on the second dressing surface 32. That is, when the dresser 3 is positioned at the outer peripheral edges 14 of the upper and lower platens 11 and 12, the contact length in the platen circumferential direction X between the first region 33 and the polishing pad 12a can be gradually reduced from one side portion 32c in the platen radial direction Y of the second dressing surface 32 toward the other side portion 32d in the platen radial direction Y. Further, when the dresser 3 is positioned at the inner peripheral edges 15 of the upper and lower platens 11 and 12, the contact length in the platen circumferential direction X between the first region 33 and the polishing pad 12a can be gradually reduced from the other side portion 32d in the platen radial direction Y of the second dressing surface 32 toward one side portion 31c in the platen radial direction Y.

[0072] Thereby, the difference between the amount of abrasion of the polishing pad 12a in the outer peripheral portion (near the outer peripheral edge 14) and the inner peripheral portion (near the inner peripheral edge 15) of the lower platen 12 and the amount of abrasion of the polishing pad 12a in the intermediate portion in the radial direction of the lower platen 12 can be reduced, and the flatness of the polishing pad 12a can be improved.

[0073] Furthermore, in the dressing device 1 of the first embodiment, exfoliation of abrasive grains in the first region 33 on the second dressing surface 32 can be suppressed, catching of the sharp portion 36 on the second dressing surface 32 on the polishing pad 12a can be suppressed, and damage to the polishing pad 12a can be prevented.

[0074] As described above, the dressing device of the present invention has been described based on the first embodiment. However, the specific configuration is not limited to this embodiment, and design changes, additions, etc. are allowed as long as the gist of the invention according to each claim of the claims is not deviated from.

[0075] In Example 1, an example was shown in which the groove portion 37 has a first groove portion 37a, a second groove portion 37b, and a third groove portion 37c. However, the groove portion 37 only needs to have any one of the first to third groove portions 37a to 37c. Also, the groove portion 37 does not necessarily have to be formed on the first dressing surface 31 and the second dressing surface 32. Further, the size (width and depth) of the groove portion 37 can be arbitrarily set. Furthermore, the number of the second groove portion 37b and the third groove portion 37c and the positions where they are formed can also be arbitrarily set.

[0076] Also, in Example 1, an example was shown in which the dressing device 1 includes a dresser 3 having a first dressing surface 31 and a second dressing surface 32, and the upper platen 11 and the lower platen 12 of the double-sided polishing machine 10 can be dressed simultaneously. However, the dresser 3 is not limited to this. The dresser 3 may be, for example, a dresser 3 having only the first dressing surface 31 facing the polishing pad 11a of the upper platen 11 or a dresser 3 having only the second dressing surface 32 facing the polishing pad 12a of the lower platen 12. In this case, the shapes of the first and second dressing surfaces 31 and 32 can be made into optimal shapes according to the upper platen rotation direction CCW and the lower platen rotation direction CW.

[0077] In Example 1, an example was shown in which the first dressing surface 31 has a shape in which the dimension W in the platen radial direction Y gradually increases from one end 31a in the platen circumferential direction X to the other end 31b in the platen circumferential direction X. However, for example, when the dresser 3 is inserted between the upper and lower platens 11 and 12 along the platen radial direction Y, the tangent direction Lα of the outer peripheral edge 14 when the dresser 3 contacts the outer peripheral edge 14 of the upper and lower platens 11 and 12 and the tangent direction Lβ of the inner peripheral edge 15 when the dresser 3 contacts the inner peripheral edge 15 of the upper and lower platens 11 and 12 are parallel.

[0078] Therefore, the dimension W in the platen radial direction Y from one end 31a in the platen circumferential direction X to the other end 31b in the platen circumferential direction X of the first dressing surface may be constant.

[0079] Also, in the dressing device 1 of Example 1, the partition line 35 is composed of a straight line connecting the first corner 35a and the third corner 35c (midpoint), and a straight line connecting the second corner 35b and the third corner 35c (midpoint). However, the shape of the partition line 35 is not limited to this. For example, it may be composed of an arc with the third corner 35c as the vertex, or may be composed of a stepped broken line connecting the first corner 35a and the third corner 35c (midpoint) and a stepped broken line connecting the second corner 35b and the third corner 35c (midpoint).

[0080] Also, in the dressing device 1 of Example 1, an example was shown in which large R machining was performed on both one end 31a in the surface plate circumferential direction X and the other end 31b in the surface plate circumferential direction X of the first dressing surface 31. However, the shape of the first dressing surface 31 is not limited to this. The first dressing surface 31 may be subjected to R machining on either one end 31a in the surface plate circumferential direction X or the other end 31b in the surface plate circumferential direction X, or may not be subjected to R machining on either of the ends 31a and 31b.

[0081] Furthermore, in the dressing device 1 of Example 1, an example was shown in which the flatness of the polishing pads 11a and 12a was improved. However, by controlling the position of the third corner 35c (midpoint), it is possible to control the way of reduction when the contact length in the surface plate circumferential direction X between the first region 33 and the polishing pads 11a and 12a decreases from the side portion 31c toward the side portion 31d, and the way of reduction when the contact length in the surface plate circumferential direction X between the first region 33 and the polishing pads 11a and 12a decreases from the side portion 31d toward the side portion 31c. That is, it is also possible to intentionally control the outer peripheral portion and the inner peripheral portion of the polishing pads 11a and 12a into shapes such as tachi (a state where the amount of shaving of the outer peripheral portion and the inner peripheral portion is small) and sag (a state where the amount of shaving of the outer peripheral portion and the inner peripheral portion is large).

[0082] In addition, for the dressing device 1 of Example 1, based on the shapes of the outer peripheral portions and inner peripheral portions of the polishing pads 11a and 12a after actual dressing, the shape of the contact area between the first region 33 and the polishing pads 11a and 12a (the shape of the region surrounded by the X-axis, the Y-axis, and the line indicating the contact length in the surface plate circumferential direction X between the first region 33 and the polishing pad 11a) can be appropriately set, and the shape of the first region 33 (the position of the third corner portion 35c) can be designed based on the set shape of the contact area. Thereby, the shapes of the polishing pads 11a and 12a can be finely controlled.

[0083] Furthermore, in the dressing device 1 of Example 1, although an example in which the dresser 3 has the cleaning water injection mechanism 3b is shown, the cleaning water does not necessarily have to be ejected from the dresser 3. That is, the dresser 3 may not have the cleaning water injection mechanism 3b.

[0084] In addition, the double-sided polishing machine 10 equipped with the dressing device 1 may have a mechanism for fixing the upper surface plate 11 during dressing. In that case, dressing may be performed in a state where the upper surface plate 11 is fixed by a mechanism (hereinafter referred to as the "upper surface plate suspension fixing mechanism") that fixes the upper surface plate 11 in a suspended state at a position raised to a predetermined height.

[0085] The upper platen suspension fixing mechanism is provided on the apparatus frame that supports the upper platen 11 and the upper platen suspension portion provided on the upper platen 11 in a suspended state. The upper platen suspension fixing mechanism can restrain the vertical position (height) and sway of the upper platen 11. Note that the upper platen suspension fixing mechanism can have an arbitrary structure and shape, such as a mechanism in which a locking member provided on the apparatus frame in a U-shape, cylindrical shape, claw shape, etc., capable of driving for locking and unlocking, is locked to a locked member provided on the upper platen suspension portion to fix the apparatus frame and the upper platen suspension portion, or conversely, a mechanism in which a locking member capable of driving for locking and unlocking is provided on the upper platen suspension portion and the locked member is provided on the apparatus frame. The driving direction when locking and unlocking the locking member may be other directions as long as locking is possible with respect to the locked portion in addition to the horizontal direction. Note that the upper platen suspension fixing mechanism is not limited to the auto-dressing technology of the present invention, and can also be applied to dressing by other types of surface plates and pad dressers, as well as all maintenance work of surface plates.

Explanation of Signs

[0086] 1 Dressing device 2 Arm member 3 Dresser 3a Dressing member 31 First dressing surface 31a One end in the circumferential direction of the surface plate 31b The other end in the circumferential direction of the surface plate 31c One side portion in the radial direction of the surface plate (the side portion on the outer peripheral side in the radial direction of the surface plate) 31d The other side portion in the radial direction of the surface plate (the side portion on the inner peripheral side in the radial direction of the surface plate) 32 Second dressing surface 33 First region 34 Second region 35 Partition line 35a First corner 35b Second corner 35c Third corner (midpoint) 35d Fourth corner 35e Fifth corner 36 Sharp portion 37 Groove portion 37a First groove 37b Second groove part 37c Third groove part 10 Double-sided grinding machine 11 Upper platen 11a Grinding pad 12 Lower platen 12a Grinding pad 13 Rotating shaft 14 Outer periphery 15 Inner periphery X Platen circumferential direction Y Platen radial direction Lα Tangential direction of outer periphery Lβ Tangential direction of inner periphery

Claims

【Claim 1】 In a dressing device comprising a dresser for dressing a polishing pad attached to a surface plate for polishing a workpiece, the dresser has a dressing surface facing the polishing pad, a first region having a predetermined dressing force and a second region having a dressing force lower than that of the first region are set on the dressing surface, the first region and the second region are arranged side by side in the circumferential direction of the surface plate, and the first region is disposed on one end side in the circumferential direction of the surface plate of the dressing surface, a partition line partitioning the first region and the second region has an intermediate point set at a position closer to one end in the circumferential direction of the surface plate than both ends in the middle part in the radial direction of the surface plate, the dressing surface has a shape in which the dimension in the radial direction of the surface plate gradually increases from one end in the circumferential direction of the surface plate toward the other end in the circumferential direction of the surface plate. When the dresser is located at the outer peripheral edge of the surface plate, the side portion on the outer peripheral side in the radial direction of the surface plate is along the tangential direction of the outer peripheral edge of the surface plate. When the dresser is located at the inner peripheral edge of the surface plate, the side portion on the inner peripheral side in the radial direction of the surface plate is along the tangential direction of the inner peripheral edge of the surface plate, the intermediate point is set on the intersection of a first straight line parallel to the tangential direction of the inner peripheral edge of the surface plate and passing through the intersection of the side portion on the outer peripheral side in the radial direction of the dressing surface and one end in the circumferential direction of the surface plate, and a second straight line parallel to the tangential direction of the outer peripheral edge of the surface plate and passing through the intersection of the side portion on the inner peripheral side in the radial direction of the dressing surface and one end in the circumferential direction of the surface plate, an angle formed by the tangential direction of the outer peripheral edge of the surface plate and the partition line and an angle formed by the tangential direction of the inner peripheral edge of the surface plate and the partition line are set to the same angle, and an angle formed by the tangential direction of the outer peripheral edge of the surface plate and the first straight line and an angle formed by the tangential direction of the inner peripheral edge of the surface plate and the second straight line are set to the same angle, the contact length in the circumferential direction of the surface plate between the polishing pad and the first region gradually decreases from the side portion on the outer peripheral side in the radial direction of the dressing surface toward the side portion on the inner peripheral side in the radial direction of the dressing surface when the dresser is located at the outer peripheral edge of the surface plate, and gradually decreases from the side portion on the inner peripheral side in the radial direction of the dressing surface toward the side portion on the outer peripheral side in the radial direction of the dressing surface when the dresser is located at the inner peripheral edge of the surface plate A dressing device characterized by the above. **Claim 2**: The dressing device according to claim 1, wherein on the dressing surface, a groove portion is formed which allows the fluid supplied during the dressing to flow and is open to the side of the dresser. The dressing device is characterized by this. **Claim 3**: The dressing device according to claim 2, wherein the groove portion has a first groove portion along the partition line. The dressing device is characterized by this. **Claim 4**: The dressing device according to claim 2 or 3, wherein the groove portion has a second groove portion along the circumferential direction of the surface plate. The dressing device is characterized by this. **Claim 5**: The dressing device according to any one of claims 2 to 4, wherein the groove portion has a third groove portion that extends from the center position in the radial direction of the surface plate of the dressing surface toward the side in the radial direction of the surface plate, following the downstream direction with respect to the rotation of the surface plate. The dressing device is characterized by this. **Claim 6**: The dressing device according to any one of claims 1 to 5, wherein the dressing surface is subjected to R processing on at least one of one end in the circumferential direction of the surface plate or the other end in the circumferential direction of the surface plate. The dressing device is characterized by this. The dressing device is characterized by this.

Images