JP7711938B2 - Dressing Equipment - Google Patents

Description

The present invention relates to a dressing device that dresses a polishing pad attached to the platen of a polishing machine that polishes a workpiece.

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

In the example shown in Fig. 13(a) and (b), the first grinding wheel 101 and the second grinding wheel 102 are set to the same length, but there are also dressing devices in which the lengths of the rod-shaped first grinding wheel 201 and the second grinding wheel 202 are different, such as the modified dresser 200 shown in Fig. 14(a) and (b). In the conventional dresser 200 shown in Fig. 14(a) and (b), the first grinding wheel 201 has a dressing surface 201a facing the upper platen, and the second grinding wheel 202 has a dressing surface 202a facing the lower platen. The dresser 200 presses the first grinding wheel 201 against the upper platen with the first cylinder 204a for pressing through the elastic member (leaf spring, etc.) 203, and presses the second grinding wheel 202 against the lower platen with the second cylinder 204b for pressing.

Furthermore, conventionally, there is known a dressing device in which the dressing surface has an inner region located on the inner edge side of the platen during dressing, an outer region located on the outer edge side of the platen during dressing, and an intermediate region located between the inner region and the outer region (see, for example, Patent Document 2). Here, the inner region extends a required length in the platen radial direction and is formed in a shape that follows the inner edge of the platen. The outer region extends a required length in the platen radial direction and is formed in a shape that follows the outer edge of the platen. Furthermore, the intermediate region extends a required length in the platen radial direction and is set so that the length of the intermediate region extending in the platen circumferential direction is shorter than the length of the inner region and the outer region extending in the platen circumferential direction.

JP 2020-124750 A Patent No. 6535529

However, for example, in the dressing device described in Patent Document 1, the amount of polishing pad removed is small at the outer and inner periphery of the platen, and there is a difference in the amount of polishing pad removed between the outer and inner periphery of the platen and the middle part. This makes it difficult to uniformly flatten the entire surface of the polishing pad. Also, for example, in the dressing device described in Patent Document 2, there is a tendency for the polishing pad to be removed too much near the outer and inner edges of the platen during dressing, and the amount of polishing pad removed varies greatly between the outer and inner periphery of the platen.

The present invention was made with the above problem in mind, and aims to provide a dressing device that can improve the flatness of the polishing pad during dressing and make the amount of polishing pad removed uniform.

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 platen for polishing a workpiece, the dresser having a dressing surface facing the polishing pad, and a first region having a predetermined dressing force and a second region having a dressing force lower than that of the first region set on the dressing surface. The first region and the second region are aligned in the circumferential direction of the platen, and the first region is disposed on one end side of the dressing surface in the circumferential direction of the platen. Furthermore, a dividing line dividing the first region and the second region has a midpoint set at a position closer to one end of the dressing surface in the circumferential direction of the platen than both end portions at a midpoint in the radial direction of the platen . The dressing surface has a shape in which the dimension in the radial direction of the platen gradually increases from one end in the circumferential direction of the platen to the other end in the circumferential direction of the platen, and when the dresser is located on the outer circumferential edge of the platen, the outer circumferential side of the platen in the radial direction is aligned along the tangential direction of the outer circumferential edge of the platen, and when the dresser is located on the inner circumferential edge of the platen, the inner circumferential side of the platen in the radial direction is aligned along the tangential direction of the inner circumferential edge of the platen. The midpoint is set on the intersection of a first straight line that is parallel to the tangential direction of the inner circumferential edge of the platen and passes through the intersection of the outer circumferential side of the dressing surface in the radial direction and the one end in the circumferential direction of the platen, and a second straight line that is parallel to the tangential direction of the outer circumferential edge of the platen and passes through the intersection of the inner circumferential side of the dressing surface in the radial direction and the one end in the circumferential direction of the platen. The angle between the tangent direction of the outer peripheral edge of the platen and the dividing line is set to the same angle, and the angle between the tangent direction of the inner peripheral edge of the platen and the dividing line is set to the same angle, and the angle between the tangent direction of the outer peripheral edge of the platen and the first straight line is set to the same angle, and the angle between the tangent direction of the inner peripheral edge of the platen and the second straight line is set to the same angle. The contact length between the polishing pad and the first region in the platen circumferential direction is gradually reduced from a side portion on the outer peripheral side in the platen radial direction of the dressing surface to a side portion on the inner peripheral side in the platen radial direction of the dressing surface when the dresser is located at the outer peripheral edge of the platen, and is gradually reduced from a side portion on the inner peripheral side in the platen radial direction of the dressing surface to a side portion on the outer peripheral side in the platen radial direction of the dressing surface when the dresser is located at the inner peripheral edge of the platen .

The dressing device of the present invention can improve the flatness of the polishing pad during dressing and make the amount of polishing pad removed uniform.

FIG. 2 is an explanatory diagram illustrating a dressing device and a double-sided polisher according to the first embodiment. FIG. 2 is a plan view showing a schematic diagram of the dressing device and the double-sided polishing machine of the first embodiment. FIG. 2 is a plan view showing a first dressing surface of the dresser of the first embodiment. FIG. 4 is a plan view showing a second dressing surface of the dresser of the first embodiment. FIG. 2 is a plan view showing a first region set on a first dressing surface in Example 1. FIG. 6 is an enlarged view of the AA cross section in FIG. 5. FIG. 4 is an explanatory diagram showing the shape of a first region. 13 is a diagram showing the contact length in the circumferential direction of the platen between the first region and the polishing pad at the radial position of the first region on the platen; FIG. 1A is a diagram showing the amount of removal of the polishing pad by the dressing device of Example 1. FIG. 1B is an explanatory diagram showing the measurement positions of the amount of removal of the polishing pad. 1A is a plan view showing a first region of the first comparative example, FIG. 1B is a diagram showing a contact length in the circumferential direction of a platen between the first region of the first comparative example and a polishing pad, and FIG. 1C is a diagram showing an amount of polishing of the polishing pad by the first region of the first comparative example. 1A is a plan view showing a first region of the second comparative example, FIG. 1B is a diagram showing a contact length in the circumferential direction of a platen between the first region of the second comparative example and a polishing pad, and FIG. 1C is a diagram showing an amount of polishing of the polishing pad by the first region of the second comparative example. 1A is a plan view showing a first region of the first modified example, FIG. 1B is a diagram showing a contact length in the circumferential direction of a polishing pad between the first region of the first modified example, and FIG. 1C is a diagram showing an amount of polishing of the polishing pad by the first region of the first modified example. 1A is a first perspective view showing a dresser of a conventional dressing apparatus, and FIG. 1B is a second perspective view showing a dresser of a conventional dressing apparatus. 1A is a first perspective view showing a modified example of a dresser of a conventional dressing apparatus, and FIG. 1B is a second perspective view showing a modified example of a dresser of a conventional dressing apparatus.

Below, a form for implementing the dressing device of the present invention will be described based on Example 1 shown in the drawings.

The dressing device 1 of the first embodiment is a dressing device for a double-sided polisher that simultaneously dresses the polishing pad 11a attached to the upper platen 11 of the double-sided polisher 10 that polishes both the front and back sides of a thin workpiece, and the polishing pad 12a attached to the lower platen 12 of the double-sided polisher 10. Note that dressing refers to grinding or roughening the surfaces of the polishing pads 11a and 12a to recover the slurry retention of the polishing pads 11a and 12a and maintain the polishing ability of the double-sided polisher 10. It is desirable that the surfaces of the polishing pads 11a and 12a are uniformly flattened by dressing, or that the amount of polishing of the polishing pads is made uniform.

During dressing, the dressing device 1 places the dresser 3 between the upper and lower platens 11 and 12. In addition, the double-sided polisher 10 rotates the upper platen 11 in a first direction (e.g., counterclockwise, hereinafter referred to as the "upper platen rotation direction CCW") by the rotating shaft 13 while sandwiching the dresser 3 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 (e.g., clockwise, hereinafter referred to as the "lower platen rotation direction CW"). As a result, the polishing pads 11a and 12a come into sliding contact with the dresser 3, and the polishing pads 11a and 12a are dressed. In addition, both the upper platen 11 and the lower platen 12 have a donut disk shape with the rotating shaft 13 attached to their centers, and during dressing, the dresser 3 moves between the outer periphery 14 and inner periphery 15 of the upper and lower platens 11 and 12.

As shown in Figures 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.

The arm member 2 is a pipe member whose base 2a is held by the drive mechanism 4 arranged near the double-sided polisher 10 and which extends horizontally from the drive mechanism 4. The arm member 2 is rotated around the base 2a by the drive mechanism 4, and the tip 2b is moved between the upper and lower surface plates 11 and 12. That is, the tip 2b of the arm member 2 moves along an arc-shaped track 2c centered on the base 2a, as shown in FIG. 2. The arm member 2 is rotated between the upper and lower surface plates 11 and 12 during dressing, and moves the dresser 3 along the track 2c. The arm member 2 is also rotated to a position where the dresser 3 is retracted from between the upper and lower surface plates 11 and 12 except when dressing is being performed.

The dresser 3 has a dressing member 3a and a cleaning 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) that faces the upper platen 11 during dressing, and a flat second dressing surface 32 (see FIG. 4) that faces the lower platen 12 during dressing. Abrasive grains are electroplated on the first dressing surface 31 and the second dressing surface 32, and the grain size is set arbitrarily. Diamond, CBN abrasive grains, etc. can be used as the abrasive grains electroplated on the first dressing surface 31 and the second dressing surface 32. The multiple circular holes 3c provided on the first dressing surface 31 and the second dressing surface 32 shown in FIG. 3 and FIG. 4 are screw holes that are arbitrarily formed.

The cleaning water injection mechanism 3b has a function of injecting high-pressure cleaning water during dressing. The cleaning water injection mechanism 3b has a pair of first injection ports 38 (see FIG. 3) provided on the sides of the first dressing surface 31, three second injection ports 39 (see FIG. 4) provided on the sides 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 ports 38 and the second injection ports 39. The cleaning water is supplied through the inside of the arm member 2. Here, the first injection port 38 is located upstream of the first dressing surface 31 in the upper platen rotation direction CCW. The second injection port 39 is located upstream of the second dressing surface 32 in the lower platen rotation direction CW. Furthermore, 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.

As shown in Figure 5, the first dressing surface 31 has a shape in which the dimension W in the platen radial direction Y (direction perpendicular to the platen circumferential direction X; see Figures 2 to 5), which is the radial direction of the upper and lower platens 11, 12, gradually increases from one end 31a in the platen circumferential direction X (see Figures 2 to 5), which is the circumferential direction of the upper and lower platens 11, 12, to the other end 31b in the platen circumferential direction X. As a result, as shown in Figure 2, one side 31c (side on the outer periphery) of the first dressing surface 31 in the platen radial direction Y is aligned along the tangent direction Lα of the outer periphery 14 when the dresser 3 is positioned at the outer periphery 14 of the upper and lower platens 11, 12 during dressing. In addition, the other side 31d (the inner peripheral side) of the first dressing surface 31 in the platen radial direction Y is aligned with the tangent direction Lβ of the inner peripheral edge 15 when the dresser 3 is positioned at the inner peripheral edge 15 of the upper and lower platens 11 and 12 during dressing. Furthermore, both ends 31a, 31b of the first dressing surface 31 in the platen circumferential direction X extend approximately parallel to each other. Therefore, the first dressing surface 31 has an approximately trapezoidal shape in a plan view.

Here, "when the dresser 3 is located on the outer periphery 14 of the upper and lower surface plates 11, 12" means that the dresser 3 has moved to the outermost periphery of the upper and lower surface plates 11, 12. Also, "when the dresser 3 is located on the inner periphery 15 of the upper and lower surface plates 11, 12" means that the dresser 3 has moved to the innermost periphery of the upper and lower surface plates 11, 12.

The first dressing surface 31 has a large R on both ends 31a and 31b in the circumferential direction X of the platen to reduce the contact force with the polishing pad 11a.

The first dressing surface 31 has a first region 33 and a second region 34. The first region 33 has abrasive grains with a relatively large grain size electroplated therein, and is set to a relatively low grain size (coarse grain size) such as #50 to #325. The second region 34 has abrasive grains with a smaller grain size than the first region 33 electroplated therein, and is set to a higher grain size (fine grain size) than the first region 33, such as #325 to #3000. The first region 33 and the second region 34 are set to be flush with each other, as shown in FIG. 6. In other words, the distance from the first region 33 to the polishing pad 11a and the distance from the second region 34 to the polishing pad 11a are the same.

The first region 33 and the second region 34 are arranged side by side along the circumferential direction X of the base plate. Here, the first region 33 is arranged on one end 31a side of the base plate in the circumferential direction X, and the second region 34 is arranged on the other end 31b side of the base plate in the circumferential direction X. The first region 33 and the second region 34 are divided by a dividing line 35.

As shown in FIG. 5, the dividing line 35 is formed by a straight line connecting the first corner 35a, the second corner 35b, and the third corner 35c (midpoint). Here, the first corner 35a is a point set on one side 31c of the first dressing surface 31 in the radial direction Y of the platen. The second corner 35b is a point set on the other side 31d of the first dressing surface 31 in the radial direction Y of the platen. The third corner 35c is a point set in the middle of the first dressing surface 31 in the radial direction Y of the platen. The third corner 35c is set at a position closer to one end 31a of the first dressing surface 31 in the circumferential direction X of the platen than the first and second corners 35a, 35b located on both sides 31c, 31d in the radial direction Y of the platen.

As a result, the first region 33 has sharpened portions 36 formed at both ends in the radial direction Y of the platen at the boundary position with the second region 34. The second region 34 is located between the two sharpened portions 36.

In Example 1, the sharpened portion 36 is rounded. Therefore, in Example 1, the first corner portion 35a and the second corner portion 35b are set on both sides 31c, 31d in the imaginary radial direction Y of the base plate when it is assumed that the sharpened portion 36 is not rounded, that is, on straight lines along each side portion 31c, 31d.

7, the third corner portion 35c is set at the intersection of the first straight line L1 and the second straight line L2 set on the first dressing surface 31. Here, the first straight line L1 is parallel to the tangent direction Lβ of the inner peripheral edge 15 of the upper and lower surface plates 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 an intersection point between one side portion 31c of the first dressing surface 31 in the surface plate radial direction Y and one end portion 31a in the surface plate circumferential direction X. The second straight line L2 is parallel to the tangent direction Lα of the outer peripheral edge 14 of the upper and lower surface plates 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 35e is the intersection of the other side 31d of the first dressing surface 31 in the platen radial direction Y and one end 31a in the platen circumferential direction X.

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

In addition, in Example 1, the angle θ5 between the tangent direction Lα of the outer peripheral edge 14 and the tangent direction Lβ of the inner peripheral edge 15 is set to the same angle as the angles θ3 and θ4. Note that the angle θ5 is set according to the length of the arm member 2 or the size of 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.

Then, by setting the third corner 35c at the intersection of the first straight line L1 and the second straight line L2 and setting θ1 and θ2, and θ3 and θ4 to the same angles, when the dresser 3 is located at the outer periphery 14 of the upper and lower surface plates 11 and 12, as shown in FIG. 8, the contact length in the circumferential direction of the surface plate between the first region 33 and the polishing pad 11a gradually decreases from one side 31c (the side on the outer periphery 14 side of the upper and lower surface plates 11 and 12) in the surface plate radial direction Y of the first dressing surface 31 (the side on the inner periphery 15 side of the upper and lower surface plates 11 and 12). Note that the hole 3c is not taken into account in the contact length in the circumferential direction of the surface plate shown in FIG. 8.

Furthermore, in FIG. 8, the area surrounded by the X-axis, Y-axis, and lines indicating the contact length in the circumferential direction of the platen between the first region 33 and the polishing pad 11a (hatched area) indicates the contact area between the first region 33 and the polishing pad 11a. When the dresser 3 is located at the outer periphery 14 of the upper and lower platens 11, 12, as can be seen from FIG. 8, the contact area between the first region 33 and the polishing pad 11a gradually decreases from the outermost periphery of the upper and lower platens 11, 12, and presents an approximately triangular shape when illustrated with the horizontal axis being the platen radial direction Y.

In addition, when the dresser 3 is positioned at the inner peripheral edge 15 of the upper and lower surface plates 11, 12, the contact length in the surface plate circumferential direction X between the first region 33 and the polishing pad 11a gradually decreases from the other side 31d of the first dressing surface 31 in the surface plate radial direction Y (the side on the inner peripheral edge 15 side of the upper and lower surface plates 11, 12) toward one side 31c in the surface plate radial direction Y (the side on the outer peripheral edge 14 side of the upper and lower surface plates 11, 12).

In other words, the contact length between the first region 33 and the polishing pad 11a in the circumferential direction X of the platen gradually decreases from the platen edge (the outer peripheral edge 14 or the inner peripheral edge 15) side toward the platen interior (the middle part of the platen radial direction Y of the upper and lower platens 11, 12) side, whether the dresser 3 is positioned on the outer peripheral edge 14 of the upper and lower platens 11, 12 or on the inner peripheral edge 15 of the upper and lower platens 11, 12.

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

Furthermore, a groove portion 37 is formed on the first dressing surface 31. The groove portion 37 is a depression formed on 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 allows the flow of fluids such as cleaning water supplied during dressing.

The groove portion 37 in Example 1 has a first groove portion 37a, a second groove portion 37b, and a third groove portion 37c.

The first groove portion 37a extends along the dividing line 35. The first groove portion 37a divides the first region 33 and the second region 34.

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

The third groove portion 37c extends from the center position of the first dressing surface 31 in the platen radial direction Y toward the side portions 31c and 31d in the platen radial direction Y in a direction following the downstream direction relative to the rotation of the upper platen 11. Note that the "direction following the downstream direction relative to the rotation of the upper platen 11" refers to a direction in which the fluid that has flowed into the groove portion 37 flows downstream in the upper platen rotation direction CCW. The third groove portion 37c is formed only in the first region 33.

The second dressing surface 32 is located on the opposite side of the first dressing surface 31 and has a similar shape to the first dressing surface 31 as shown in FIG. 4, so a detailed description is omitted.

The second dressing surface 32 also has a first region 33 set to a predetermined grain size (e.g., #50 to #325, etc.) and a second region 34 set to a higher grain size (e.g., #325 to #3000, etc.) than the first region 33. The first region 33 and second region 34 set on the second dressing surface 32 and the first region 33 and second region 34 set on the first dressing surface 31 have the same shape, so a detailed description will be omitted.

Furthermore, a groove portion 37 having a first groove portion 37a, a second groove portion 37b, and a third groove portion 37c is formed on the second dressing surface 32. Here, the shapes of the first groove portion 37a and the second groove portion 37b are similar to those of the first groove portion 37a and the second groove portion 37b formed on the first dressing surface 31, so a detailed description is omitted.

On the other hand, the third groove portion 37c formed on the second dressing surface 32 extends from the center position of the second dressing surface 32 in the platen radial direction Y toward the side portions 32c and 32d in the platen radial direction Y in a direction following the downstream direction with respect to the rotation of the lower platen 12. Note that the "direction following the downstream direction with respect to the rotation of the lower platen 12" refers to the direction in which the fluid that has flowed into the groove portion 37 flows downstream in the lower platen rotation direction CW. Here, the upper platen rotation direction CCW and the lower platen rotation direction CW are opposite directions. Therefore, as shown in FIG. 4, the third groove portion 37c formed on the second dressing surface 32 extends in a different direction from the third groove portion 37c formed on the first dressing surface 31.

The operation of the dressing device 1 of Example 1 is described below.

When dressing the polishing pads 11a and 12a of the double-sided polisher 10, the dressing device 1 of Example 1 controls each part using a control unit (not shown), and first rotates the arm member 2 using the drive mechanism 4. Then, the drive mechanism 4 places the dresser 3 provided at the tip 2b of the arm member 2 between the upper platen 11 and the lower platen 12.

Next, the double-sided polisher 10 sets the gap height between the upper platen 11 and the lower platen 12 to a predetermined height. As a result, the dresser 3 is sandwiched between the upper and lower platens 11 and 12, and the first dressing surface 31 contacts the polishing pad 11a of the upper platen 11, and the second dressing surface 32 contacts the polishing pad 12a of the lower platen 12.

The double-sided polisher 10 then rotates the upper platen 11 and the lower platen 12 in opposite directions around the rotation axis 13 with the first and second dressing surfaces 31, 32 in contact with the polishing pads 11a, 12a, respectively. 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 along the track 2c from the outer periphery 14 side to the inner periphery 15 side of the upper and lower platen 11, 12, while bringing the polishing pads 11a, 12a into sliding contact with the dresser 3, thereby dressing the polishing pads 11a, 12a.

Here, in the dressing device 1 of Example 1, the first dressing surface 31 has a shape in which the dimension W in the radial direction Y of the platen gradually increases from one end 31a in the circumferential direction X of the platen toward the other end 31b in the circumferential direction X of the platen. In addition, in the dressing device 1 of Example 1, a first region 33 having a predetermined grain size and a second region 34 having a grain size higher than that of the first region 33 are set on the first dressing surface 31. In addition, the first region 33 and the second region 34 are aligned in the circumferential direction X of the platen, and the first region 33 is disposed on the side of one end 31a in the circumferential direction X of the platen. Furthermore, the dividing line 35 dividing the first region 33 and the second region 34 has a third corner 35c in the middle of the platen radial direction Y, which is set closer to one end 31a in the platen circumferential direction X than both ends (first corner 35a, second corner 35b) in the platen radial direction Y.

As a result, the contact length in the circumferential direction X of the polishing pad 11a and the first region 33, which has a lower grain size (coarser grain) than the second region 34 and therefore a higher dressing force than the second region 34, can be gradually reduced from the edge of the plate (the outer peripheral edge 14 or the inner peripheral edge 15) toward the inside of the plate (the middle part of the plate radial direction Y of the upper and lower platens 11, 12) both when the dresser 3 is located on the outer peripheral edge 14 of the upper and lower platens 11, 12 and when the dresser 3 is located on the inner peripheral edge 15 of the upper and lower platens 11, 12 (see, for example, Figure 8). As a result, as shown in FIG. 9A, the difference between the amount of polishing pad 11a removed at the outer periphery (near outer edge 14) and inner periphery (near inner edge 15) of upper platen 11 and the amount of polishing pad 11a removed at the radially intermediate portion of upper platen 11 can be reduced without overhanging dresser 3. As a result, the dressing device 1 of Example 1 can improve the flatness of polishing pad 11a.

In addition, the dressing device 1 of Example 1 uses a dressing force based on the grain size, but a dressing force obtained by the density, material, arrangement, etc. of the abrasive grains may also be used. In other words, the dressing device 1 varies the magnitude of the dressing force by adjusting the grain size, but the magnitude of the dressing force may also be changed by adjusting the density, material, arrangement, etc. of the abrasive grains.

"Overhanging" refers to dressing the upper platen 11 with a part of the dresser 3 protruding outside the platen relative to the outer periphery 14 and inner periphery 15. When the dresser 3 is overhanging, it is possible to dress the polishing pads 11a, 12a in the desired state on the outer periphery and inner periphery of the upper and lower platen 11, 12. However, in this case, it is difficult to control, as it is difficult to adjust the position of the dresser 3 and interference occurs between the dresser 3 and structures such as the internal gear and sun gear. For this reason, it is preferable not to overhang the dresser 3.

The amount of polishing pad 11a removed shown in FIG. 9(a) is a value measured along measurement line LS shown in FIG. 9(b). Furthermore, the amount of polishing pad 11a removed shown in FIG. 9(a) is a value measured when the movement of the dresser 3 along the track 2c 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 surface plate 11 and when the first dressing surface 31 contacts the inner peripheral edge 15 during dressing.

In addition, for example, in the case of a dresser having a first region 33X having a rectangular shape in a plan view, as in the first comparative example shown in FIG. 10(a), when the dresser is located on the outer periphery 14 or inner periphery 15 of the upper and lower surface plates 11 and 12, the dressing surface contacts the outer periphery 14 or inner periphery 15 in an oblique direction due to the rotation of the arm member 2. Therefore, for example, when the dresser of the first comparative example is located on the outer periphery 14 of the upper and lower surface plates 11 and 12, the contact length between the first region 33X and the polishing pad 11a in the surface plate circumferential direction X does not continue to decrease from one side 31c in the surface plate radial direction Y to the other side 31d in the surface plate radial direction Y, as shown in FIG. 10(b). In addition, the contact area between the first region 33X and the polishing pad 11a shown with diagonal lines in FIG. 10(b) is trapezoidal when the horizontal axis is the surface plate radial direction Y.

As a result, as shown in FIG. 10(c), the amount of polishing pad 11a removed is less at the outer and inner periphery of the upper platen 11 compared to Example 1. On the other hand, the amount of polishing pad 11a removed is greater at the radially middle portion of the upper platen 11 compared to Example 1. As a result, the difference between the amount of polishing pad 11a removed at the outer and inner periphery of the upper platen 11 and the amount of polishing pad 11a removed at the middle portion of the upper platen 11 is greater than in Example 1, and the flatness of polishing pad 11a cannot be improved.

In addition, 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 in the second comparative example shown in FIG. 11(a), when the dresser of the second comparative example is located on the outer periphery 14 of the upper and lower base plates 11 and 12, the contact length between the first region 33Y and the polishing pad 11a in the base plate circumferential direction X does not gradually decrease from one side 31c in the base plate radial direction Y to the other side 31d in the base plate radial direction Y, as shown in FIG. 11(b), but increases halfway and then decreases again. Note that the contact area between the first region 33Y and the polishing pad 11a shown with diagonal lines in FIG. 11(b) is in the shape of two triangles lined up when the horizontal axis is the base plate radial direction Y.

As a result, as shown in FIG. 11(c), the increase in the amount of polishing pad 11a removed varies greatly between the outer and inner periphery of upper platen 11, resulting in a so-called step D. As a result, the flatness of polishing pad 11a cannot be improved.

Furthermore, in the dressing device 1 of Example 1, a second region 34 is set on the first dressing surface 31, which has a higher grain size (finer mesh) than the first region 33 and a lower dressing force than the first region 33. Here, the second region 34 is arranged in line with the first region 33 along the circumferential direction X of the platen. This makes it possible to suppress the impact force acting on the edge of the first groove portion 37a and to protect the portion of the periphery of the first region 33 along the dividing line 35, i.e., the sharp tip portion 36.

In addition, the second region 34 protects the periphery of the sharpened tip 36, which can suppress the peeling of abrasive grains at the sharpened tip 36. Furthermore, the second region 34 can hold down the polishing pad 11a, making it difficult for the sharpened tip 36 to get caught on the polishing pad 11a, preventing damage to the polishing pad 11a.

For example, if the second region 34 is formed of a flat metal surface or the like that does not have a dressing force, there is a risk that the second region 34 will destroy the grain of the polishing pad 11a that has been roughened by the first region 33. For this reason, it is undesirable to make the second region 34 a surface that does not have a dressing force, such as a metal surface. In contrast, in the dressing device 1 of Example 1, by giving the second region 34 a dressing force lower than the first region 33, the polishing pad 11a is not actively roughened, but the grain of the polishing pad 11a that has been roughened by the first region 33 can be prevented from being destroyed.

Furthermore, since the second region 34 only needs to have a lower dressing force than the first region 33, it may be made of a material with dressing force, such as a relatively soft brush, a high-grit grindstone, or a roughened surface of ceramics, in addition to abrasive grains.

In the dressing device 1 of Example 1, the third corner portion 35c set on the dividing line 35 is set on the intersection of a first straight line L1 parallel to the tangent direction Lβ of the inner peripheral edge 15 of the upper surface plate 11 and a second straight line L2 parallel to the tangent direction Lα of the outer peripheral edge 14 of the upper surface plate 11. Furthermore, the angle θ1 between the tangent direction Lα and the dividing line 35 and the angle θ2 between the tangent direction Lβ and the dividing line 35 are set to the same angle, and the angle θ3 between the tangent direction Lα and the first straight line L1 and the angle θ4 between the tangent direction Lβ and the second straight line L2 are set to the same angle.

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

For example, in the case where 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 modified example shown in FIG. 12(a), when the dresser 3 is located on the outer periphery 14 of the upper and lower surface plates 11 and 12, as shown in FIG. 12(b), the reduction rate of the contact length in the circumferential direction X of the first region 33A and the polishing pad 11a changes significantly at the midway position (middle position) from the side 31c to the side 31d. Also, although not shown, when the dresser 3 is located on the inner periphery 15 of the upper and lower surface plates 11 and 12, the reduction rate of the contact length in the circumferential direction X of the first region 33A and the polishing pad 11a changes significantly at the midway position (middle position) from the side 31d to the side 31c. Furthermore, the contact area between the first region 33, which is shown with diagonal lines in FIG. 12(b), and the polishing pad 11a does not form a triangle when illustrated with the horizontal axis representing the platen radial direction Y.

However, even in such a case, as shown in FIG. 12(c), it is possible to suppress the variation in the amount of polishing pad 11a removed at the outer and inner periphery of the upper platen 11 and at the radial middle portion, thereby improving the flatness of the polishing pad 11a.

However, it is desirable that the shortest distance B from the straight line connecting the fourth corner 35d and the fifth corner 35e to the third corner 35c be at least 10% of the shortest distance A from the straight line connecting the first corner 35a and the second corner 35b to the third corner 35c. If the distance B is shorter than this, the area of the first region 33A will be narrowed, the dressing function of the dressing device 1 will be reduced, and it will become less practical.

In addition, in the dressing device 1 of Example 1, a groove portion 37 is formed on the first dressing surface 31 through which cleaning water (fluid) supplied when performing dressing can flow, and which is open to the side of the dresser 3.

As a result, the dressing device 1 of Example 1 can use the cleaning water flowing through the groove portion 37 to remove grinding debris from the polishing pad 11a generated by dressing, as well as deposits and by-products attached to the polishing pad 11a, from between the first dressing surface 31 and the polishing pad 11a.

In particular, in Example 1, the groove portion 37 has a first groove portion 37a that is aligned with the dividing line 35. This allows a gap to be created between the first region 33 and the second region 34, improving the discharge performance of grinding debris. This makes it possible to prevent clogging of the dresser 3.

In addition, in Example 1, the groove portion 37 has a second groove portion 37b along the circumferential direction X of the platen. This improves the discharge performance of the cleaning water flowing along the circumferential direction X of the platen, and improves the discharge performance of the grinding debris. This makes it possible to suppress clogging of the dresser 3.

Furthermore, in Example 1, the groove portion 37 has a third groove portion 37c that extends from the center position of the first dressing surface 31 in the platen radial direction Y toward both side portions 31c and 31d in the platen radial direction Y in a direction following the downstream direction relative to the rotation of the upper platen 11. This improves the discharge performance of grinding debris and suppresses clogging of the dresser 3.

Furthermore, in the dressing device 1 of Example 1, the first dressing surface 31 is subjected to R processing on both one end 31a in the circumferential direction X of the platen and the other end 31b in the circumferential direction X of the platen. This makes it possible to reduce resistance between both ends 31a, 31b of the first dressing surface 31 and the polishing pad 11a. This makes it possible to prevent the first dressing surface 31 from getting caught on the polishing pad 11a, and to suppress damage to the polishing pad 11a and the abrasive grains.

In the dressing device 1 of Example 1, the second dressing surface 32 can also provide the same effect as the first dressing surface 31. That is, when the dresser 3 is located on the outer periphery 14 of the upper and lower surface plates 11 and 12, the dressing device 1 of Example 1 can gradually reduce the contact length between the first region 33 and the polishing pad 12a in the surface plate circumferential direction X from one side 32c in the surface plate radial direction Y of the second dressing surface 32 to the other side 32d in the surface plate radial direction Y. Also, when the dresser 3 is located on the inner periphery 15 of the upper and lower surface plates 11 and 12, the contact length between the first region 33 and the polishing pad 12a in the surface plate circumferential direction X can be gradually reduced from the other side 32d in the surface plate radial direction Y of the second dressing surface 32 to one side 31c in the surface plate radial direction Y.

This reduces the difference between the amount of polishing pad 12a removed at the outer periphery (near outer edge 14) and inner periphery (near inner edge 15) of the lower surface plate 12 and the amount of polishing pad 12a removed at the radial middle part of the lower surface plate 12, thereby improving the flatness of the polishing pad 12a.

Furthermore, the dressing device 1 of Example 1 can suppress the peeling of abrasive grains in the first region 33 on the second dressing surface 32, and can also suppress the sharpened portion 36 on the second dressing surface 32 from getting caught on the polishing pad 12a, thereby preventing damage to the polishing pad 12a.

The dressing device of the present invention has been described above based on Example 1, but the specific configuration is not limited to this example, and design changes and additions are permitted as long as they do not deviate from the gist of the invention as defined by each claim in the scope of the claims.

In Example 1, an example is shown in which the groove portion 37 has the first groove portion 37a, the second groove portion 37b, and the third groove portion 37c. However, it is sufficient that the groove portion 37 has any of the first to third groove portions 37a to 37c. Furthermore, the groove portion 37 does not necessarily have to be formed on the first dressing surface 31 and the second dressing surface 32. Furthermore, the size (width and depth) of the groove portion 37 can be set arbitrarily. Furthermore, the number of the second groove portions 37b and the third groove portions 37c and the positions at which they are formed can also be set arbitrarily.

In addition, in Example 1, an example was shown in which the dressing device 1 is equipped with a dresser 3 having a first dressing surface 31 and a second dressing surface 32, and can simultaneously dress the upper platen 11 and the lower platen 12 of the double-sided polisher 10. However, the dresser 3 is not limited to this. The dresser 3 may be, for example, a dresser 3 having only a first dressing surface 31 facing the polishing pad 11a of the upper platen 11, or a dresser 3 having only a second dressing surface 32 facing the polishing pad 12a of the lower platen 12. In this case, it is possible to make the shapes of the first and second dressing surfaces 31 and 32 optimal according to the upper platen rotation direction CCW and the lower platen rotation direction CW.

In Example 1, an example is shown in which the first dressing surface 31 has a shape in which the dimension W in the radial direction Y of the platen gradually increases from one end 31a in the circumferential direction X of the platen toward the other end 31b in the circumferential direction X of the platen. However, for example, when the dresser 3 is inserted between the upper and lower platens 11 and 12 along the radial direction Y of the platen, 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.

Therefore, the first dressing surface may have a constant dimension W in the radial direction Y of the base plate from one end 31a in the circumferential direction X of the base plate to the other end 31b in the circumferential direction X of the base plate.

In the dressing device 1 of Example 1, the dividing 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 dividing line 35 is not limited to this, and may be composed of, for example, an arc with the third corner 35c as an apex, 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).

In addition, in the dressing device 1 of Example 1, an example is shown in which a large R processing is performed on both one end 31a in the circumferential direction X of the first dressing surface 31 and the other end 31b in the 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 R processed on either one end 31a in the circumferential direction X of the first dressing surface 31 or the other end 31b in the circumferential direction X of the first dressing surface 31, or neither end 31a nor 31b may be R processed.

Furthermore, in the dressing device 1 of Example 1, an example of improving the flatness of the polishing pads 11a and 12a was shown. However, by controlling the position of the third corner portion 35c (midpoint), it is possible to control the manner in which the contact length between the first region 33 and the polishing pads 11a and 12a in the circumferential direction X of the platen is reduced from the side portion 31c toward the side portion 31d, and the manner in which the contact length between the first region 33 and the polishing pads 11a and 12a in the circumferential direction X of the platen is reduced from the side portion 31d toward the side portion 31c. In other words, it is also possible to intentionally control the outer and inner peripheral portions of the polishing pads 11a and 12a to have shapes such as a ridge (a state in which the amount of cutting of the outer and inner peripheral portions is small) or a sag (a state in which the amount of cutting of the outer and inner peripheral portions is large).

The dressing device 1 of Example 1 can also appropriately set the shape of the contact area between the first region 33 and the polishing pads 11a and 12a (the shape of the area surrounded by the X-axis, Y-axis, and a line indicating the contact length between the first region 33 and the polishing pad 11a in the circumferential direction X of the platen) from the shapes of the outer and inner peripheries of the polishing pads 11a and 12a after actual dressing, and can design the shape of the first region 33 (the position of the third corner portion 35c) based on the shape of the set contact area. This allows for precise control of the shapes of the polishing pads 11a and 12a.

Furthermore, in the dressing device 1 of Example 1, an example is shown in which the dresser 3 has a cleaning water spraying mechanism 3b, but cleaning water does not necessarily have to be able to be sprayed from the dresser 3. In other words, the dresser 3 does not necessarily have to have a cleaning water spraying mechanism 3b.

The double-sided polishing machine 10 equipped with the dressing device 1 may have a mechanism for fixing the upper platen 11 during dressing. In that case, dressing may be performed with the upper platen 11 fixed in a position where it has been raised to a predetermined height by a mechanism for fixing the upper platen 11 in a suspended state (hereinafter referred to as the "upper platen hanging part fixing mechanism").

The upper platen suspension fixing mechanism is provided on the device frame that supports the upper platen 11 and the upper platen suspension provided on the upper platen 11 in a suspended state. The upper platen suspension fixing mechanism can prevent the upper platen 11 from being moved in the vertical direction (height) or from vibrating. The upper platen suspension fixing mechanism can be of any structure and shape, such as a mechanism in which a locking member provided on the device frame, such as a U-shaped, cylindrical, or claw-shaped locking member that can be driven to lock and release, is locked to a locked member provided on the upper platen suspension to fix the device frame and the upper platen suspension, or a mechanism in which a locking member that can be driven to lock and release is provided on the upper platen suspension and the locked member is provided on the device frame. The driving direction when locking and unlocking the locking member may be any direction other than the horizontal direction as long as it can be locked to the locked part. The upper platen suspension fixing mechanism can be applied not only to the auto-dressing technology of the present invention, but also to dressing using other types of platen dressers and pad dressers, as well as to maintenance work on all types of platens.

1 Dressing device 2 Arm member 3 Dresser 3a Dressing member 31 First dressing surface 31a One end portion in the circumferential direction of the platen 31b The other end portion in the circumferential direction of the platen 31c One side portion in the radial direction of the platen (side portion on the outer circumferential side of the platen in the radial direction)
31d: the other side in the radial direction of the surface plate (the inner 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 Sharpened portion 37 Groove 37a First groove 37b Second groove 37c Third groove 10 Double-sided polisher 11 Upper surface plate 11a Polishing pad 12 Lower surface plate 12a Polishing pad 13 Rotary shaft 14 Outer periphery 15 Inner periphery X Surface plate circumferential direction Y Surface plate radial direction Lα Tangential direction of outer periphery Lβ Tangential direction of inner periphery

Claims (6)

A dressing apparatus including a dresser for dressing a polishing pad attached to a platen for polishing a workpiece,
the dresser has a dressing surface facing the polishing pad;
The dressing surface is provided with a first region having a predetermined dressing force and a second region having a lower dressing force than the first region,
The first region and the second region are aligned in a circumferential direction of the platen, and the first region is disposed on one end side of the dressing surface in the circumferential direction of the platen,
A dividing line dividing the first region and the second region has a midpoint set at a position closer to one end in the circumferential direction of the platen than both end portions in a middle portion in the radial direction of the platen,
the dressing surface has a shape in which a dimension in the radial direction of the platen gradually increases from one end in the circumferential direction of the platen to the other end in the circumferential direction of the platen, and when the dresser is located on the outer circumferential edge of the platen, a side portion on the outer circumferential side of the platen in the radial direction is aligned along a tangential direction of the outer circumferential edge of the platen, and when the dresser is located on the inner circumferential edge of the platen, a side portion on the inner circumferential side of the platen in the radial direction is aligned along a tangential direction of the inner circumferential edge of the platen,
the midpoint is set on an intersection of a first straight line which is parallel to a tangential direction of an inner peripheral edge of the platen and passes through an intersection point between a side portion of the dressing surface on the outer peripheral side in the radial direction of the platen and one end portion in the circumferential direction of the platen, and a second straight line which is parallel to a tangential direction of an outer peripheral edge of the platen and passes through an intersection point between a side portion of the dressing surface on the inner peripheral side in the radial direction of the platen and one end portion in the circumferential direction of the platen,
The angle between the tangential direction of the outer peripheral edge of the platen and the dividing line and the angle between the tangential direction of the inner peripheral edge of the platen and the dividing line are set to the same angle, and the angle between the tangential direction of the outer peripheral edge of the platen and the first straight line and the angle between the tangential direction of the inner peripheral edge of the platen and the second straight line are set to the same angle,
A contact length between the polishing pad and the first region in the circumferential direction of the platen gradually decreases from a side portion of the dressing surface on the outer circumferential side in the radial direction of the platen to a side portion of the dressing surface on the inner circumferential side in the radial direction of the platen when the dresser is located on the outer circumferential edge of the platen, and gradually decreases from a side portion of the dressing surface on the inner circumferential side in the radial direction of the platen to a side portion of the dressing surface on the outer circumferential side in the radial direction of the platen when the dresser is located on the inner circumferential edge of the platen.
A dressing apparatus comprising: 2. The dressing apparatus according to claim 1 ,
a groove portion, which is open to a side of the dresser, and through which a fluid supplied during the dressing can flow, is formed on the dressing surface. 3. The dressing apparatus according to claim 2 ,
The dressing device, wherein the groove portion has a first groove portion extending along the partition line. 4. The dressing apparatus according to claim 2 ,
The dressing device according to claim 1, wherein the groove portion has a second groove portion extending along a circumferential direction of the platen. The dressing apparatus according to any one of claims 2 to 4 ,
The dressing device according to claim 1, wherein the groove portion has a third groove portion extending from a center position of the dressing surface in the radial direction of the platen toward a side portion in the radial direction of the platen in a direction following a downstream direction with respect to rotation of the platen. The dressing apparatus according to any one of claims 1 to 5 ,
The dressing device according to claim 1, wherein the dressing surface is subjected to R processing on at least one of one end portion in a circumferential direction of the platen or the other end portion in the circumferential direction of the platen.