JP2020093381A - Discoidal work-piece processing method - Google Patents

Abstract

To process a discoidal work-piece so that the discoidal work-piece already polished has uniform thicknesses.SOLUTION: A work-piece processing method comprises: a step in which a discoidal work-piece is held on a table 5; a step in which the work-piece is ground with a grindstone by rotating the work-piece and a grinding wheel 304; a step in which the work-piece is polished with a polishing pad 44 covering the work-piece, by rotating the work-piece already ground and the polishing pad 44; a step in which thicknesses of the work-piece are measured in at least two points of a first measurement point P1 at a center of the work-piece already polished and a second measurement point P2 near an outer peripheral edge of the work-piece; a step in which a thickness tendency in a radial direction of the work-piece is recognized from the thicknesses of the work-piece measured in the two measurement points P1 and P2; and a step in which an inclination relation between a rotary shaft 300 attached with the grinding wheel 304 and a rotary shaft 571 of the table 5 is changed in order to form in the subsequent grinding step a work-piece having the thickness tendency opposed to the thickness tendency recognized in the thickness tendency recognition step.SELECTED DRAWING: Figure 5

Description

The present invention relates to a processing method for grinding and polishing a disk-shaped work.

In the case where a device chip is manufactured from a disc-shaped work, etc., as disclosed in Patent Document 1, after the disc-shaped work is ground by a grinding wheel to be thinned, the surface to be ground of the disc-shaped work is The surface to be ground is polished with a polishing pad having a polishing surface with an area covering the area.

In the grinding process, a grinding wheel in which a grinding wheel is annularly arranged is rotated, and the disk-shaped work is ground by the grinding wheel to a uniform thickness. In order to grind a disk-shaped work to a uniform thickness, as disclosed in Patent Document 2, grinding is temporarily stopped during the grinding process, and in the radius of the disk-shaped work, the center point of the radius and the The thickness of the disk-shaped work is measured at a total of three points, that is, two points that are separated from each other by the same distance in the center direction and the outer circumferential direction from the midpoint. Then, the inclination relationship between the spindle shaft that rotates the grinding wheel and the table rotation shaft of the holding table that holds the disk-shaped work is changed so that the difference in thickness of the disk-shaped work at the three measurement points is eliminated. ..

When polishing a disk-shaped work that has been ground to a uniform thickness, the polishing pad may take a long time to contact, so that the central part of the disk-shaped work is often polished, resulting in a disk-shaped work with a concave shape. .. Further, in a grinding and polishing apparatus that uses a holding table for grinding and polishing, the holding surface of the holding table has a conical shape with the center at the apex. When the disc-shaped work after grinding held by the conical holding table is polished, the polishing pad is strongly applied to the center of the disc-shaped work, so that the center is easily polished. As a measure against this, as disclosed in Patent Document 3, the polishing surface of the polishing pad is partially dressed, and the polishing surface is formed so that the center of the polishing surface does not hit the disk-shaped work strongly. The thickness of the disk-shaped work after polishing is made uniform.

JP, 2005-153090, A JP, 2013-119123, A JP, 2005-223636, A

However, in the polishing process in which the time for pressing the polishing pad against the disk-shaped work is lengthened, even if the polishing surface of the polishing pad is dressed in a desired shape as disclosed in Patent Document 3, the polishing pad is There is a problem that the disk-shaped work after being crushed and polished becomes a concave shape.
Furthermore, when the dressing makes the polishing pad thinner, the cushioning property of the polishing pad becomes smaller, and the polishing pad is strongly pressed against the center part of the disk-shaped work held by the holding table, and the disk-shaped work after polishing becomes a concave shape. There is a problem of becoming.
Therefore, when processing a disk-shaped work, there is a problem that the disk-shaped work after polishing is processed to have a uniform thickness.

The present invention for solving the above-mentioned problems is a method for processing a disc-shaped work in which a disc-shaped work held on a holding surface of a holding table is ground by a grinding wheel and polished by a polishing pad, and A holding step of holding the disk-shaped work, a grinding step of rotating the disk-shaped work and the grinding wheel respectively to grind the disk-shaped work with the grinding wheel, and the disk after the grinding step Polishing step in which the circular workpiece and the polishing pad are respectively rotated to polish the circular workpiece while the polishing pad covers the circular workpiece, and a first measurement point at the center of the circular workpiece after the polishing step. And a measurement step of measuring the thickness of the disc-shaped work at at least two measurement points near the outer peripheral edge of the disc-shaped work, and the two measurement points measured in the measurement step. And a thickness tendency recognizing a thickness tendency in the radial direction of the disk-shaped work from the thickness of the disk-shaped work, and a thickness tendency contrary to the thickness tendency recognized in the thickness tendency recognition step in the next grinding step. In order to form the disc-shaped workpiece, the inclination changing step of changing the inclination relation between the rotation axis on which the grinding wheel is mounted and the rotation axis of the holding table is performed. ..

In the method for processing a disk-shaped workpiece according to the present invention, in the measuring step, a third measuring point which is an intermediate point between the two measuring points and the first measuring point and the second measuring point. And measuring the thickness of the disc-shaped work at at least three measurement points, and in the thickness tendency recognition step, the thickness of the disc-shaped work at least at the three measurement points is measured in the radial direction of the disc-shaped work. It is preferable to recognize the thickness tendency in.

In the method for processing a disk-shaped work according to the present invention, the thickness of the disk-shaped work is measured before the polishing step at at least two measurement points of the first measurement point and the second measurement point. The pre-polishing measuring step, and the circle at the two measuring points measured in the measuring step from the thickness of the disk-shaped workpiece at the two measuring points measured in the pre-polishing measuring step before the inclination changing step. And a calculation step of calculating the polishing removal amount at the two measurement points by subtracting the thickness of the plate-shaped work, in the inclination changing step, the polishing removal amount is subtracted from the thickness tendency recognized in the thickness tendency recognition step. Further, in order to form a disk-shaped work having a thickness tendency contrary to the thickness tendency of the disk-shaped work in the next grinding step, a tilt relationship between the rotary shaft on which the grinding wheel is mounted and the rotary shaft of the holding table is formed. Is preferably changed.

In the disk-shaped workpiece processing method according to the present invention, in the pre-polishing measurement step, a third measurement point that is an intermediate point between the two measurement points and the first measurement point and the second measurement point is provided. The thickness of the disk-shaped workpiece is measured at at least three measurement points with the measurement points, in the measurement step, the thickness of the disk-shaped workpiece is measured at least at the three measurement points, and in the calculation step, Polishing at the three measurement points by subtracting the thickness of the disk-shaped work at the three measurement points measured at the measurement step from the thickness of the disk-shaped work at the three measurement points measured at the pre-polishing measurement step It is preferable that the removal amount is calculated, and in the thickness tendency recognition step, the thickness tendency in the radial direction of the disk-shaped work is recognized from the thickness of the disk-shaped work at least at the three measurement points.

The method for processing a disk-shaped work according to the present invention includes a holding step of holding the disk-shaped work on a holding table, and a grinding process of rotating the disk-shaped work and a grinding wheel to grind the disk-shaped work with a grinding wheel. After the grinding step, the disk-shaped work and the polishing pad are respectively rotated to polish the disk-shaped work while the polishing pad covers the disk-shaped work. A measurement step of measuring the thickness of the disk-shaped work at at least two points, that is, one measurement point and a second measurement point near the outer peripheral edge of the disk-shaped work, and a circle at the two measurement points measured in the measurement step. It violates the thickness tendency recognition step that recognizes the thickness tendency (for example, the tendency to be concave) in the radial direction of the disk-shaped work from the thickness of the plate-shaped work, and the thickness tendency recognized in the thickness tendency recognition step in the next grinding step. An inclination changing step of changing the inclination relationship between the rotation axis on which the grinding wheel is mounted and the rotation axis of the holding table in order to form a disk-shaped work piece having a thickness tendency (for example, a tendency to have a medium convex shape). By including the new disk-shaped work, it becomes possible to flatten the new disk-shaped work with higher accuracy after polishing than the disk-shaped work that has been previously polished.
Incidentally, during the grinding and polishing process, the polishing pad is regularly dressed, and when the dressing is repeated and the thickness of the polishing pad becomes thin, there is a phenomenon that the polishing pad is more likely to have a concave shape. The disc-shaped workpiece machining method is such that even when the polishing pad is regularly dressed, the new disc-shaped workpiece is highly accurately flattened after polishing as compared with the disc-shaped workpiece previously polished. It becomes possible.

In the method for processing a disk-shaped workpiece according to the present invention, in the measuring step, at least the two measuring points and a third measuring point which is an intermediate point between the first measuring point and the second measuring point. By measuring the thickness of the disk-shaped work at three measurement points and recognizing the thickness tendency in the radial direction of the disk-shaped work from the thickness of the disk-shaped work at at least three measurement points in the thickness tendency recognition step. When changing the tilt relationship between the rotary shaft on which the grinding wheel is mounted and the rotary shaft of the holding table in the tilt changing step, the tilt relationship can be changed more appropriately than when there are two measurement points. Becomes

In the method for processing a disk-shaped work according to the present invention, a pre-polishing measurement step of measuring the thickness of the disk-shaped work at at least two measurement points including a first measurement point and a second measurement point before the polishing step. And before the inclination changing step, two measurement points are obtained by subtracting the thickness of the disk-shaped workpiece at the two measurement points measured in the measurement step from the thickness of the disk-shaped workpiece at the two measurement points measured in the pre-polishing measurement step. In the inclination changing step, a circle having a thickness tendency contrary to the thickness tendency of the disk-shaped work obtained by subtracting the polishing removal amount calculated from the thickness tendency recognized in the thickness tendency recognition step in the inclination changing step. In order to form a plate-shaped work in the next grinding process, a new disc-shaped work is polished first by changing the tilt relationship between the rotation axis of the grinding wheel and the rotation axis of the holding table. It becomes possible to perform flattening with higher accuracy after polishing than with a disc-shaped work.

In the disk-shaped workpiece processing method according to the present invention, in the pre-polishing measurement step, the two measurement points and the third measurement point which is an intermediate point between the first measurement point and the second measurement point are included. The thickness of the disk-shaped work is measured at at least three measurement points of, the thickness of the disk-shaped work is measured at at least three measurement points in the measurement step, and the thickness of the disk-shaped work measured in the pre-polishing measurement step is calculated in the calculation step. The polishing removal amount at the three measurement points is calculated by subtracting the thickness of the disk-shaped work at the three measurement points measured in the measurement step from the thickness of the disk-shaped work at the measurement points. By recognizing the thickness tendency of the disk-shaped work in the radial direction from the thickness of the disk-shaped work at the measurement point, change the tilt relationship between the rotation axis on which the grinding wheel is mounted and the rotation axis of the holding table in the tilt change process. In this case, it is possible to change the inclination relationship more appropriately than when there are two measurement points.

It is a perspective view showing an example of a grinding and polishing device. It is a perspective view showing a position adjusting unit, a holding table, and a holding table rotating means. It is explanatory drawing which shows the example of arrangement|positioning of the position adjustment unit which comprises an inclination adjustment means. It is sectional drawing which shows the example of a position adjustment unit. 6 is a flowchart illustrating a flow of each step of the method for processing a disk-shaped work according to the first embodiment. It is sectional drawing explaining the state which made the holding|maintenance table hold|maintain the disk-shaped workpiece. It is sectional drawing explaining the state which grinds a disk-shaped work with a grinding grindstone, rotating a plate-shaped work and a grinding wheel, respectively. It is explanatory drawing at the time of seeing from above the processing area|region of the disk-shaped workpiece|work by a grinding wheel during grinding. FIG. 6 is a cross-sectional view illustrating a state in which a disc-shaped work and a polishing pad are respectively rotated to perform polishing with the polishing pad covering the disc-shaped work. It is explanatory drawing at the time of seeing from below the processing area|region of the disk-shaped work by the polishing pad in polishing processing. A first measurement point at the center of the disc-shaped work, a second measurement point near the outer peripheral edge of the disc-shaped work, and a third point that is an intermediate point between the first measurement point and the second measurement point. It is sectional drawing explaining the state which is measuring the thickness of a disk-shaped workpiece|work at three points, a measurement point. In order to form a disk-shaped work with a thickness tendency contrary to the thickness tendency recognized in the next process for recognizing the thickness tendency in the grinding process for a new disk-shaped work, the rotation axis with the grinding wheel and the rotation axis of the holding table It is sectional drawing explaining the state which is changing the inclination relationship with. 9 is a flowchart illustrating the flow of each step of the method for processing a disk-shaped work according to the second embodiment. It is sectional drawing explaining the state which made the holding table hold|maintain the 1st disc-shaped work. It is sectional drawing explaining the state which is rotating the 1st plate-shaped work and each grinding wheel, and grinds a disk-shaped work with a grinding wheel. The first measurement point at the center of the first disk-shaped work before polishing, the second measurement point near the outer peripheral edge of the disk-shaped work, the first measurement point and the second measurement point It is sectional drawing explaining the state which is measuring the thickness of a disk-shaped workpiece|work at three points, the 3rd measurement point which is an intermediate point. FIG. 7 is a cross-sectional view illustrating a state in which the first disk-shaped work and the polishing pad are respectively rotated to perform polishing with the polishing pad covering the disk-shaped work. The first measurement point at the center of the first disk-shaped work after polishing, the second measurement point near the outer peripheral edge of the disk-shaped work, the first measurement point and the second measurement point It is sectional drawing explaining the state which is measuring the thickness of a disk-shaped workpiece|work at three points, the 3rd measurement point which is an intermediate point. Contrary to the thickness tendency recognized in the thickness tendency recognition step for the first disk-shaped workpiece, the thickness tendency obtained by subtracting the polishing removal amount from the recognized thickness tendency, and the thickness tendency subtracting the polishing removal quantity, the next grinding step FIG. 7 is an explanatory diagram for explaining a thickness tendency to be formed on the second disk-shaped work. The second disc-shaped work having a thickness tendency contrary to the thickness tendency of the first disc-shaped work obtained by subtracting the polishing removal amount calculated from the thickness tendency recognized in the thickness tendency recognition step is formed in the next grinding step. Therefore, it is a cross-sectional view for explaining a case of changing the inclination of the rotation axis of the holding table. FIG. 6 is a cross-sectional view illustrating a state in which a second disk-shaped work is held by a holding table and ground to a desired thickness. The first measurement point at the center of the second disk-shaped work before polishing, the second measurement point near the outer peripheral edge of the disk-shaped work, the first measurement point and the second measurement point It is sectional drawing explaining the state which is measuring the thickness of a disk-shaped workpiece|work at three points, the 3rd measurement point which is an intermediate point. FIG. 6 is a cross-sectional view illustrating a state in which the second disc-shaped work and the polishing pad are respectively rotated to perform polishing with the polishing pad covering the disc-shaped work. The first measurement point at the center of the second disk-shaped work after polishing, the second measurement point near the outer peripheral edge of the disk-shaped work, the first measurement point and the second measurement point It is sectional drawing explaining the state which is measuring the thickness of a disk-shaped workpiece|work at three points, the 3rd measurement point which is an intermediate point. It is sectional drawing explaining the inclination maintenance in the inclination change process in the 2nd disk-shaped workpiece. FIG. 6 is a cross-sectional view illustrating a state in which a third disk-shaped work is held by a holding table and is ground to have a desired thickness. The first measurement point at the center of the third disk-shaped work before polishing, the second measurement point near the outer peripheral edge of the disk-shaped work, the first measurement point and the second measurement point It is sectional drawing explaining the state which is measuring the thickness of a disk-shaped workpiece|work at three points, the 3rd measurement point which is an intermediate point. FIG. 7 is a cross-sectional view illustrating a state in which the third disc-shaped work and the polishing pad are respectively rotated to perform polishing with the polishing pad covering the disc-shaped work. The first measurement point at the center of the third disk-shaped work after polishing, the second measurement point near the outer peripheral edge of the disk-shaped work, the first measurement point and the second measurement point It is sectional drawing explaining the state which is measuring the thickness of a disk-shaped workpiece|work at three points, the 3rd measurement point which is an intermediate point.

The grinding and polishing apparatus 1 shown in FIG. 1 includes a rough grinding unit 30, a finish grinding unit 31, and a polishing unit 4, and a disk-shaped work W held on any one of the holding tables 5 is roughly ground and finished. This is a device for grinding by the grinding means 31 and further by the grinding means 4.
The grinding/polishing device 1 is configured, for example, by connecting a second device base 11 to the rear (+Y direction side) of the first device base 10. The first device base 10 has a loading/unloading area A in which the disk-shaped workpiece W is loaded/unloaded. On the second device base 11, there is a processing area B in which the disk-shaped work W held by the holding table 5 by the rough grinding means 30, the finish grinding means 31 or the polishing means 4 is processed.

The disk-shaped work W shown in FIG. 1 is, for example, a circular semiconductor wafer made of a silicon base material or the like, and a plurality of devices are formed on the surface Wa of the disk-shaped work W facing downward in FIG. A protective tape (not shown) is attached and protected. The back surface Wb of the disk-shaped work W is a surface to be processed that is subjected to grinding and polishing. The disk-shaped work W may be made of gallium arsenide, sapphire, gallium nitride, silicon carbide, or the like other than silicon.

The first cassette mounting portion 150 and the second cassette mounting portion 151 are provided on the front side (−Y direction side) of the first device base 10, and the first cassette mounting portion 150 is provided with the first cassette mounting portion 150. Is a second cassette 151a in which the first cassette 150a in which the disk-shaped work W before processing is accommodated is placed, and the second cassette 151a in which the disk-shaped work W after processing is accommodated in the second cassette mounting portion 151. Is placed.

Behind the opening on the +Y direction side of the first cassette 150a, the disk-shaped work W before processing is carried out from the first cassette 150a and the disk-shaped work W after processing is carried into the second cassette 151a. A robot 155 is installed. A temporary placement area 152 is provided at a position adjacent to the robot 155, and a positioning means 153 is provided in the temporary placement area 152. The alignment means 153 aligns (centers) the disk-shaped work W, which has been unloaded from the first cassette 150a and placed on the temporary placement area 152, with a diameter-adjusting alignment pin at a predetermined position.

At a position adjacent to the position adjusting means 153, a loading arm 154a that rotates while holding the disk-shaped work W is arranged. The loading arm 154a holds the disc-shaped work W aligned by the alignment means 153 and conveys it to any one of the holding tables 5 arranged in the processing area B. Next to the loading arm 154a, an unloading arm 154b that rotates while holding the processed disk-shaped work W is provided. At a position close to the unloading arm 154b, a single-wafer cleaning means 156 for cleaning the processed disk-shaped workpiece W conveyed by the unloading arm 154b is arranged. The disk-shaped work W cleaned by the cleaning means 156 is carried into the second cassette 151a by the robot 155.

A first column 12 is provided upright on the rear side (on the +Y direction side) of the second device base 11, and a rough grinding feed means 20 is provided on the front surface of the first column 12. The rough grinding feed means 20 connects the ball screw 200 having a vertical (Z-axis direction) axis, a pair of guide rails 201 arranged in parallel with the ball screw 200, and connects the ball screw 200 to rotate the ball screw 200. The motor 202 includes a motor 202, an elevating plate 203 whose internal nut is screwed to the ball screw 200 and a side portion of which is in sliding contact with the guide rail 201, and a holder 204 which is connected to the elevating plate 203 and holds the rough grinding means 30. When the ball screw 200 is rotated, the elevating plate 203 is guided by the guide rail 201 to reciprocate in the Z-axis direction, and the rough grinding means 30 supported by the holder 204 also reciprocates in the Z-axis direction.

The rough grinding means 30 includes a rotary shaft 300 whose axial direction is the vertical direction (Z-axis direction), a housing 301 which rotatably supports the rotary shaft 300, a motor 302 which rotationally drives the rotary shaft 300, and a rotary shaft 300. A circular mount 303 connected to the lower end of the mount 303 and a grinding wheel 304 detachably connected to the lower surface of the mount 303. The grinding wheel 304 includes a wheel base 304a and a plurality of rough grinding wheels 304b that are annularly arranged on the bottom surface of the wheel base 304a and have a substantially rectangular parallelepiped shape. The rough grinding wheel 304b is, for example, a wheel in which the abrasive grains contained in the wheel are relatively large.
For example, a grinding water flow path extending in the Z-axis direction is formed inside the rotary shaft 300, and a grinding water supply unit (not shown) communicates with the grinding water flow path. The grinding water supplied from the grinding water supply means to the rotary shaft 300 is jetted downward from the opening at the lower end of the grinding water flow path toward the rough grinding wheel 304b, and the rough grinding wheel 304b and the disk-shaped work W are separated. Reach the contact area.

In the rear of the second device base 11, a second column 13 is erected on the first column 12 side by side in the X-axis direction, and a finish grinding feed is provided on the front surface of the second column 13. Means 21 are provided. The finish grinding feed means 21 is configured similarly to the rough grinding feed means 20, and can feed the finish grinding means 31 by grinding in the Z-axis direction. The finish grinding means 31 includes a finish grinding stone 314b in which the abrasive grains contained in the grindstone are relatively small, and other configurations are similar to those of the rough grinding means 30.

A third column 14 is erected on one side (-X direction side) on the second device base 11, and a Y-axis direction moving means 24 is arranged on the front surface of the third column 14. ing. The Y-axis direction moving means 24 includes a ball screw 240 having an axis in the Y-axis direction, a pair of guide rails 241 arranged in parallel with the ball screw 240, a motor 242 for rotating the ball screw 240, and an internal nut. It is composed of a movable plate 243 which is screwed onto the ball screw 240 and whose side portion is in sliding contact with the guide rail 241. When the motor 242 rotates the ball screw 240, the movable plate 243 is guided by the guide rail 241 to move in the Y-axis direction, and the polishing means 4 disposed on the movable plate 243 moves the movable plate 243. Moves in the Y-axis direction.

On the movable plate 243, polishing feed means 25 for moving the polishing means 4 up and down in the Z-axis direction, which approaches or separates from the holding table 5, is arranged. The polishing feed means 25 includes a ball screw 250 having a vertical axis, a pair of guide rails 251 arranged in parallel with the ball screw 250, a motor 252 for connecting the ball screw 250 to rotate the ball screw 250, and A motor 252 rotates the ball screw 250 by a nut 254 that is screwed onto the ball screw 250 and a side portion is slidably in contact with the guide rail 251 and a holder 254 that is connected to the elevator plate 253 and holds the polishing means 4. The elevating plate 253 is guided by the guide rails 251 to move in the Z-axis direction, and the polishing means 4 supported by the holder 254 also moves in the Z-axis direction.

The polishing means 4 is fixed to, for example, a rotary shaft 40 whose axial direction is a vertical direction, a housing 41 which rotatably supports the rotary shaft 40, a motor 42 which rotationally drives the rotary shaft 40, and a lower end of the rotary shaft 40. And a circular polishing pad 44 detachably attached to the lower surface of the mount 43. The polishing pad 44 is made of, for example, a non-woven fabric such as felt, and has a through hole formed in a central portion thereof through which slurry (polishing liquid containing loose abrasive grains) is passed. The diameter of the polishing pad 44 is about the same as the diameter of the mount 43, and is larger than the diameter of the holding table 5.

A slurry passage extending in the axial direction is formed inside the rotary shaft 40, and a slurry supply means (not shown) communicates with the slurry passage. The slurry supplied from the slurry supply means to the rotating shaft 40 is jetted from the opening at the lower end of the slurry flow path toward the polishing pad 44, passes through the through hole of the polishing pad 44, and the polishing pad 44 and the disk-shaped work W. Reach the site of contact with.

As shown in FIG. 1, a turntable 6 is arranged on the second device base 11, and four holding tables 5 are arranged on the upper surface of the turntable 6 at equal intervals in the circumferential direction. Has been done. An unillustrated air supply source for supplying air is connected to the lower surface side of the turntable 6. By blowing the air supplied from the air supply source onto the lower surface of the turntable 6, the turntable 6 can be levitated to be rotatable about the axis in the Z-axis direction. Further, a rotation shaft (not shown) for rotating the turntable 6 is provided at the center of the turntable 6, and the turntable 6 can be rotated about the axis in the Z-axis direction about the rotation shaft. it can. When the turntable 6 rotates, the four holding tables 5 revolve, and the holding tables 5 are moved from near the temporary placement area 152 to below the rough grinding means 30, below the finish grinding means 31, and below the polishing means 4. Can be positioned sequentially.

As shown in FIG. 1, the holding table 5 is provided with a porous member 50 on the upper portion, and the porous member 50 is supported while being surrounded by a frame body 502, and communicates with a suction source (not shown). The upper surface of the porous member 50 is a holding surface 50a that holds the front surface Wa of the disk-shaped work W, and is also formed into a conical surface having an extremely gentle inclination with the center of rotation of the holding table 5 as the apex. .. Then, the disk-shaped work W is also held following the holding surface 50a which is a conical surface. The inclination of the holding surface 50a is so slight that it cannot be recognized by the naked eye.

The holding table 5 is rotatable about a rotation shaft 571 that passes through the center of the holding surface 50a. As shown in FIG. 2, a pipe 571b is formed so as to penetrate the rotating shaft 571, and the pipe 571b communicates with a suction source that generates a suction force of the holding surface 50a (not shown).

The holding table 5 can be rotated by the holding table rotating means 57 shown in FIG. The holding table rotating means 57 is, for example, a pulley mechanism including the rotating shaft 571 and a motor 572 serving as a drive source for rotating the holding table 5 about the center of the holding table 5. A pulley 573 is attached to the shaft of the motor 572, and an endless belt 574 is wound around the pulley 573. The endless belt 574 is also wound around the rotating shaft 571. The motor 572 rotationally drives the pulley 573 to rotate the endless belt 574 with the rotation of the pulley 573, and the endless belt 574 rotates to rotate the rotating shaft 571 and the holding table 5.

As shown in FIG. 2, each holding table 5 includes an inclination changing unit 51 that adjusts the inclination of the rotating shaft 571.
The tilt changing unit 51 includes a support base 52 and a position adjustment unit 53 connected to the support base 52. The support base 52 includes a cylindrical support cylinder 520 and a flange 521 whose diameter is expanded from the cylindrical support 520. The support base 52 surrounds the upper side of the rotating shaft 571, and rotatably supports the rotating shaft 571 of the holding table 5 via a bearing (not shown) provided inside thereof. Then, the inclination changing unit 51 has a function of adjusting the inclination of the rotary shaft 571, that is, the inclination of the holding surface 50a by adjusting the inclination of the flange portion 521.

Two or more position adjusting units 53 shown in FIG. 2 are provided on the flange portion 521 at equal intervals in the circumferential direction. For example, as shown in FIG. 3, two position adjusting units 53 and a fixing unit 53a for fixing the flange portion 521 are arranged at 120° intervals. Also, three or more position adjusting units 53 may be provided.

As shown in FIGS. 2 and 4, the position adjusting unit 53 includes a tubular portion 531 fixed to the turntable 6 by a screw 539, a shaft 532 penetrating the tubular portion 531 and a driving portion connected to a lower end of the shaft 532. 533 and a fixing portion 534 fixed to the flange portion 521 at the upper end of the shaft 532. The drive unit 533 includes a motor 533a that rotates the shaft 532, and a speed reducer 533b that reduces the rotational speed of the shaft 532.

As shown in FIG. 4, a first male screw 532 a is formed on the upper end of the shaft 532. On the other hand, the fixing portion 534 includes a nut 535 having a first female screw 535a screwed to the first male screw 532a, and a holding nut 536 fixed to the nut 535 by a bolt 536a. The nut 535 and the holding nut 536 are provided. The flange portion 521 is sandwiched between and. A spring 536b is interposed between the bolt 536a and the shaft 532.

The tubular portion 531 is supported in a hole 6c formed in the turntable 6. Further, a reducer 533b and a motor 533a are connected to a lower end portion of the shaft 532 via a coupling 532c, and the shaft 532 can be rotated by being driven by the motor 533a. As a result, the inclination of the flange portion 521 can be changed.

For example, as shown in FIG. 1, a cylindrical support base 64 is provided in the center of the turntable 6, and on the support base 64, a rough grinding thickness measuring means 65, a finish grinding thickness measuring means 66, Also, a polishing thickness measuring means 67 is provided. Since the rough grinding thickness measuring means 65, the finish grinding thickness measuring means 66, and the polishing thickness measuring means 67 have the same structure, the structure of the rough grinding thickness measuring means 65 will be described below.

The rough grinding thickness measuring means 65 is provided with an arm 650 extending horizontally on the second apparatus base 11, and the arm 650 can be horizontally swung by a moving means 659 fixed on the support base 64. ..
An optical sensor 652, an optical sensor 653, and an optical sensor 651 are arranged on the arm 650 so as to be linearly and evenly spaced in the extending direction.

As shown in FIG. 1, the grinding and polishing apparatus 1 includes, for example, a control unit 9 that controls the entire apparatus. The control means 9 includes a CPU for performing arithmetic processing according to a control program and a storage section 90 such as a memory. The rough grinding feed means 20, the finish grinding feed means 21, the rough grinding means 30, the finish grinding means 31, and the holding table rotating means. 57 (see FIG. 2) and the like. Then, under the control of the control means 9, the rough-grinding feed means 20 (finish-grinding feed means 21) performs the grinding-feeding operation of the rough-grinding means 30 (finish-grinding means 31) in the Z-axis direction, and the rough-grinding means 30 ( The rotation operation of the grinding wheel 304 in the finish grinding means 31) and the rotation operation of the holding table 5 by the holding table rotating means 57 are controlled.

(Embodiment 1 of processing method)
Hereinafter, each step in the case where the disk-shaped workpiece W is ground and polished by using the grinding and polishing apparatus 1 shown in FIG. 1 will be described. Each step of the method for processing a disk-shaped work according to the present invention (hereinafter, referred to as the processing method of the first embodiment) is performed in the order shown in the flowchart of FIG. 5, for example.

(1) Holding Step First, by rotating the turntable 6 shown in FIG. 1, the holding table 5 in the state where the disk-shaped workpiece W is not placed revolves, and the holding table 5 reaches the vicinity of the loading arm 154a. Moving. The robot 155 pulls out one disk-shaped work W from the first cassette 150 a and moves the disk-shaped work W to the temporary placement area 152. Next, after the disc-shaped work W is centered by the alignment means 153, the loading arm 154a moves the centered disc-shaped work W onto the holding table 5. Then, as shown in FIG. 6, the disk-shaped work W is placed on the holding surface 50a with the back surface Wb facing upward so that the center of the holding table 5 and the center of the disk-shaped work W substantially coincide with each other. Placed. Note that, in FIG. 6, the configurations of the inclination changing means 51, the holding table rotating means 57, etc. are shown in a simplified manner.

Then, the suction force generated by the operation of the suction source (not shown) is transmitted to the holding surface 50a through the pipe 571b shown in FIG. 2, so that the holding table 5 holds the disk-shaped work W. In addition, the holding surface 50a, which is a gentle conical surface, is held by the inclination changing means 51 shown in FIG. 2 so that it is parallel to the grinding surface (lower surface) of the rough grinding wheel 304b of the rough grinding means 30 shown in FIG. By adjusting the inclination of the table 5 (inclination of the rotation shaft 571), as shown in FIG. 7, the back surface Wb of the disk-shaped work W suction-held following the holding surface 50a that is a conical surface, It becomes substantially parallel to the grinding surface of the rough grinding wheel 304b.

(2) Grinding process The turntable 6 shown in FIG. 1 rotates in the counterclockwise direction when viewed from the +Z direction, so that the holding table 5 in a state where the disc-shaped workpiece W is suction-held revolves, and the rough grinding means 30 is used. The rough grinding wheel 304b and the disk-shaped work W held on the holding table 5 are aligned with each other. For example, as shown in FIGS. 7 and 8, the alignment is performed by rotating the rough grinding wheel 304b by rotating the rough grinding wheel 304b horizontally with respect to the rotation center of the disk-shaped work W by a predetermined distance. It is performed so that the locus passes through the center of rotation of the disk-shaped work W.

As shown in FIG. 7, as the rotating shaft 300 is rotated at a predetermined rotation speed by the motor 302, the rough grinding wheel 304b is rotated. Further, the rough grinding means 30 is fed in the -Z direction by the rough grinding feed means 20, and the rotating rough grinding wheel 304b comes into contact with the back surface Wb of the disk-shaped work W held by the holding table 5 to perform grinding. Is done. Further, as the holding table rotating means 57 rotates the holding table 5 at a predetermined rotation speed, the disk-shaped work W held on the holding surface 50a also rotates, so that the rough grinding wheel 304b rotates the disk-shaped work W. Rough grinding is performed on the entire back surface Wb. During the rough grinding process, a grinding water supply means (not shown) supplies the grinding water to the contact part between the rough grinding wheel 304b and the back surface Wb of the disk-shaped work W through the grinding water flow path in the rotary shaft 300, and the contact part. To cool and wash.

Since the disk-shaped work W is sucked and held following the holding surface 50a which is a gentle conical surface of the holding table 5, as shown in FIG. 8, the range indicated by the arrow R1 in the rotation locus of the rough grinding wheel 304b. Inside, the rough grinding wheel 304b abuts on the disk-shaped work W to perform grinding.

After the disk-shaped work W is roughly ground up to the finish thickness, the rough grinding feed means 20 shown in FIG. 7 raises the rough grinding means 30 to separate it from the disk-shaped work W. Then, the turntable 6 shown in FIG. 1 rotates counterclockwise when viewed from the +Z direction, and the holding table 5 that sucks and holds the disk-shaped workpiece W moves to below the finishing grinding means 31.

After the finish grinding wheel 314b of the finish grinding means 31 shown in FIG. 1 and the disk-shaped workpiece W suction-held by the holding table 5 are aligned in the same manner as in the rough grinding process, the finish grinding means 31 is The finishing grinding feed means 21 feeds downward, and the rotating finishing grinding stone 314b contacts the back surface Wb of the disk-shaped workpiece W, and is held on the holding surface 50a as the holding table 5 rotates. The disk-shaped work W rotates, and the entire back surface Wb of the disk-shaped work W is finish ground. Further, the grinding water is supplied to the contact portion between the finish grinding wheel 314b and the disk-shaped work W, and the contact portion is cooled and washed. The inclination of the holding table 5 (inclination of the rotating shaft 571) is the same as that during rough grinding.

(3) Polishing Step After the finishing grinding wheel 314b is separated from the disk-shaped work W that has been ground to have a desired finishing thickness (for example, 100 μm) and the back surface Wb of which the flatness is further improved, it is shown in FIG. When the turntable 6 rotates in the counterclockwise direction when viewed from the +Z direction, the holding table 5 that holds the disc-shaped work W after finish grinding revolves, and the polishing means 4 polishes the disc-shaped work W. The holding table 5 is positioned at a predetermined polishing position. For the alignment of the disk-shaped work W with respect to the polishing pad 44 of the polishing means 4, for example, as shown in FIGS. 9 and 10, the rotation center of the polishing pad 44 is predetermined with respect to the rotation center of the disk-shaped work W. The polishing pad 44 covers the entire back surface Wb of the disk-shaped work W by shifting the distance in the horizontal direction. In the illustrated example, the outer periphery of the polishing pad 44 and the outer periphery of the disk-shaped work W are partially overlapped, but the state is not limited to this.

As shown in FIG. 9, the polishing pad 44 rotates as the rotary shaft 40 is rotationally driven by the motor 42. Further, the polishing means 4 is fed in the -Z direction by the polishing feed means 25, and the polishing pad 44 is brought into contact with the back surface Wb of the disk-shaped work W to perform the polishing process. Further, as the holding table rotating means 57 rotates the holding table 5 at a predetermined rotation speed, the disk-shaped work W held on the holding surface 50a also rotates, so that the polishing pad 44 serves as the disk-shaped work W. The entire back surface Wb is polished. Further, during the polishing process, the slurry is supplied to the contact portion between the polishing pad 44 and the back surface Wb of the disk-shaped work W.

Since the disk-shaped work W is sucked and held following the holding surface 50a, which is a gentle conical surface of the holding table 5, as shown in FIG. 10, within the range shown by the arrow R2 in the polishing surface of the polishing pad 44. At, the polishing pad 44 contacts the disk-shaped work W to perform polishing.

When the polishing means 4 is not moved in the surface direction (horizontal direction) of the disk-shaped work W during the polishing process, a striped pattern may be formed on the back surface Wb, which is the bending strength of the disk-shaped work W. It becomes a factor to reduce the strength. Therefore, during the polishing process, the Y-axis direction moving means 24 reciprocates the polishing means 4 in the Y-axis direction to slide the polishing pad 44 on the back surface Wb of the disk-shaped workpiece W in the Y-axis direction. Good.

After the polishing of one disk-shaped work W is completed, the polishing feed means 25 shown in FIG. 9 moves the polishing means 4 in the +Z direction to separate it from the polished disk-shaped work W.

(4) Measurement Step After the polishing step, for example, a first measurement point P1 at the center of the disk-shaped work W, a second measurement point P2 near the outer peripheral edge of the disk-shaped work W, and a second measurement point P2 shown in FIG. The thickness of the disk-shaped work W is measured at at least three points, that is, a third measurement point P3 which is an intermediate point between the first measurement point P1 and the second measurement point P2. The number of measurement points may be only two, that is, the first measurement point P1 and the second measurement point P2. Specifically, after the rotation of the holding table 5 is stopped, for example, the arm 650 of the polishing thickness measuring means 67 shown in FIG. 1 is pivotally moved to be positioned above the radius of the disk-shaped work W, and the optical sensor A first measurement point P1, a third measurement point P3, and a second measurement point P2 are positioned immediately below 651, 653, and 652, respectively.

For example, in the optical sensors 651, 653, 652, the built-in light projecting element irradiates the disc-shaped work W positioned below the measuring light with the measuring light, and the light receiving element receives the reflected light. Then, the optical path difference when the light receiving element receives the reflected light reflected by the back surface Wb of the disk-shaped work W and the reflected light reflected by the surface Wa after passing through the disk-shaped work W is calculated. Based on the values, the thicknesses T1, T2, and T3 of the disk-shaped workpiece W at the first measurement point P1, the second measurement point P2, and the third measurement point P3 are measured based on the principle of interferometry and the like.

(5) Thickness Tendency Recognition Step The optical sensors 651, 652, 653 of the polishing thickness measuring means 67 measure the first measurement point P1, the second measurement point P2, and the third measurement point P3 of the disc-shaped workpiece W. The information about the thicknesses T1, T2 and T3 of the slab is sent to the control means 9 shown in FIG. The information sent to the control means 9 is stored in the storage section 90 of the control means 9.
The control means 9 determines, for example, from the thicknesses T1, T2, T3 of the disk-shaped work W at the measured first measurement point P1, the second measurement point P2, and the third measurement point P3 to the disk-shaped work W. A thickness tendency recognition unit 91 that recognizes a thickness tendency in the radial direction is provided. For example, the thicknesses of the disk-shaped workpiece W at the measured first measurement point P1, second measurement point P2, and third measurement point P3 are thickness T1=99 μm, T2=102 μm, and T3=101 μm. To do. In this case, the thickness tendency recognition unit 91 tends to increase the thickness of the disk-shaped work W after polishing toward the outer side in the radial direction, in other words, the disk-shaped work W after polishing tends to have a concave shape. Judge that there is.

(6) Inclination changing step In addition, the turntable 6 rotates in the counterclockwise direction when viewed from the +Z direction, so that the holding table 5 that holds the disk-shaped workpiece W after polishing revolves, and the holding table 5 moves. It moves to the vicinity of the unloading arm 154b shown in FIG.
Next, the unloading arm 154b suction-holds the disk-shaped work W that has been subjected to the polishing process and is suction-held on the holding table 5, and the suction by a suction source (not shown) is stopped, and the holding table 5 is used. The suction holding of the disk-shaped work W is released. The unloading arm 154b conveys the disk-shaped work W from the holding table 5 to the cleaning means 156, and the cleaning means 156 cleans the disk-shaped work W. The disc-shaped workpiece W that has been cleaned is accommodated in the second cassette 151a by the robot 155.

For example, when performing grinding on a new disk-shaped work W before being ground, the control unit 9 recognizes the thickness tendency (recognized in the thickness tendency recognition step in the next grinding step for the new disk-shaped work W). In order to form a disk-shaped workpiece W having a thickness tendency against the tendency of becoming thicker toward the outside in the radial direction), the rotary shaft 300 to which the grinding wheels 304 of the rough grinding means 30 and the finish grinding means 31 are mounted, and the holding table 5. The inclination relationship with the rotation axis 571 of is changed.

For example, when the motor 533a of the drive unit 533 of the position adjustment unit 53 shown in FIG. 2 is a pulse motor that operates by a drive pulse supplied from a pulse oscillator (not shown), the control means 9 is supplied to the motor 533a. The tilt angle of the flange portion 521 by each position adjustment unit 53 is grasped by counting the number of drive pulses to be generated, and the holding table 5 with respect to the vertical rotating shaft 300 on which the grinding wheel 304 of the rough grinding means 30 is mounted. The relative inclination of the rotating shaft 571 is changed via the inclination changing means 51. That is, in the present embodiment, as shown in FIG. 12, under the control of the control means 9, the tilt angle of the rotating shaft 571 is controlled so that the tilt changing means 51 lifts the outer peripheral side of the holding table 5 in the +Z direction by a predetermined distance. To change.

The motor 533a of the drive unit 533 of the position adjustment unit 53 may be a servo motor, and a rotary encoder may be connected to the servo motor. The rotary encoder is connected to the control means 9 which also has a function as a servo amplifier, and after the operation signal is supplied from the control means 9 to the servo motor, the encoder signal (the rotation number of the servo motor) is controlled by the control means 9. Output to. The control unit 9 grasps the tilt angle of the rotation shaft 571 by the tilt changing unit 51 based on the received encoder signal.

By changing the inclination relationship between the rotary shaft 300 on which the grinding wheel 304 is mounted and the rotary shaft 571 of the holding table 5, a grinding process is performed on a new disc-shaped workpiece W held on the next holding table 5. In the case of performing the grinding in, the second measurement point P2 and the third measurement point P3, which become thicker than the first measurement point P1 in the disk-shaped work W after the grinding in the disk-shaped work W previously ground However, it is possible to perform grinding in a state in which the surface of the rough grinding wheel 304b (finishing grinding wheel 314b) is relatively raised above the first measurement point P1. Therefore, the disk-shaped work W having a thickness tendency (a tendency to become thicker toward the radially inner side) contrary to the thickness tendency (the tendency to become thicker toward the radially outer side) of the disk-shaped work W that has been polished first, In other words, the medium convex disk-shaped workpiece W can be formed by completing the grinding process.

Then, the disk-shaped workpiece W that tends to become thicker inward in the radial direction is subjected to the above-described polishing processing, so that the second measurement of the disk-shaped workpiece W that has been difficult to be polished in the previously performed polishing processing. Since the point P2 and the third measurement point P3 are polished in a state where they are more easily polished (the state where they are easily contacted by the polishing pad 44), the disk-shaped workpiece W after the new polishing process is first ground and polished. The processed disk-shaped workpiece W is flattened with higher accuracy.

As described above, the disc-shaped work machining method according to the present invention includes the holding step of holding the disc-shaped work W on the holding table 5, and the rough grinding by rotating the disc-shaped work W and the grinding wheel 304, respectively. A grinding step of grinding the disk-shaped work W with the grindstone 304b (finish grinding wheel 314b), and after the grinding step, the disk-shaped work W and the polishing pad 44 are respectively rotated so that the polishing pad 44 changes the disk-shaped work W. After the polishing step of polishing in a covered state, after the polishing step, a first measurement point P1 at the center of the disk-shaped work W, a second measurement point P2 near the outer peripheral edge of the disk-shaped work W, and, for example, the third Measurement step of measuring the thickness of the disk-shaped work W at three points P3 and P3, and the thicknesses T1, T2, T3 of the disk-shaped work W at the three measurement points P1, P2, P3 measured in the measurement step. From the thickness tendency recognizing step for recognizing a thickness tendency (for example, a tendency to have a concave shape) in the radial direction of the disk-shaped workpiece W, and a thickness tendency recognizing step for the next grinding step for the new disk-shaped workpiece W. Inclination between the rotary shaft 300 on which the grinding wheel 304 is mounted and the rotary shaft 571 of the holding table 5 in order to form a disk-shaped work W having a thickness tendency (for example, a tendency to have a convex shape) contrary to the thickness tendency. By providing the inclination changing step of changing the relationship, it is possible to highly accurately flatten the new disk-shaped work W by polishing the disk-shaped work W that has been previously polished. Becomes
In the case where the polishing pad 44 is regularly dressed during the grinding/polishing process, if the dressing is repeated and the thickness of the polishing pad 44 becomes thin, the polishing pad 44 is likely to become more concave. Even if the polishing pad 44 is regularly dressed, the method for processing the disk-shaped work W according to the present invention is performed after polishing the new disk-shaped work W after polishing the disk-shaped work W that has been processed first. It becomes possible to flatten with high accuracy.

As in the present embodiment, in the measurement process, at least three of the two measurement points P1 and P2 and the third measurement point P3 that is an intermediate point between the first measurement point P1 and the second measurement point P2 are used. The thickness of the disk-shaped work W is measured at the measurement points, and in the thickness tendency recognition step, the thickness T1 to T3 of the disk-shaped work W at the at least three measurement points P1 to P3 is measured in the radial direction of the disk-shaped work W. By recognizing the thickness tendency, it is possible to change the inclination relationship more appropriately in the inclination changing step than in the case where there are only two measurement points, that is, the first measurement point P1 and the second measurement point P2. It will be possible.

(Embodiment 2 of processing method)
Hereinafter, each step in the case where the disk-shaped workpiece W is ground and polished by using the grinding and polishing apparatus 1 shown in FIG. 1 will be described. Each step of the disk-shaped workpiece processing method according to the present invention (hereinafter, referred to as the processing method of Embodiment 2) is performed in the order shown in the flowchart of FIG. 13, for example.

(1) Holding process for the first disk-shaped work to (2) Grinding process The holding process is performed in the same manner as in the case of the first embodiment, and as shown in FIG. The work W (hereinafter, referred to as the first disk-shaped work W) is held. Further, in the grinding step, rough grinding and finish grinding are performed as in the case of the first embodiment, and as shown in FIG. 15, grinding is performed so that the disk-shaped work W has a desired finish thickness (for example, 100 μm). To be done.

(3) Pre-polishing measurement step for the first disk-shaped work Next, the first measurement point P1 at the center of the disk-shaped work W shown in FIG. The thickness of the disk-shaped workpiece W after finish grinding is measured at least at three points, namely, two measurement points P2 and a third measurement point P3 which is an intermediate point between the first measurement point P1 and the second measurement point P2. taking measurement. The number of measurement points may be only two, that is, the first measurement point P1 and the second measurement point P2. Specifically, after the rotation of the holding table 5 is stopped and the finish grinding wheel 314b is separated from the disk-shaped work W, for example, the arm 650 of the finish grinding thickness measuring means 66 shown in FIG. It is positioned above the radius of the disk-shaped work W, and the first measurement point P1, the second measurement point P2, and the third measurement point P3 are positioned immediately below the optical sensors 651, 652, and 653, respectively. Then, the thicknesses T11, T12, T13 of the disk-shaped workpiece W at the first measurement point P1, the second measurement point P2, and the third measurement point P3 are measured by the optical sensors 651, 652, 653, respectively.

The optical sensors 651, 652, 653 of the finish grinding thickness measuring means 66 measure the first measurement point P1, the second measurement point P2, and the thicknesses T11, T12 of the third measurement point P3 of the disk-shaped workpiece W, The information about T13 is sent to the control means 9 shown in FIG. The information sent to the control means 9 is stored in the storage section 90 of the control means 9. For example, the thicknesses of the disk-shaped workpiece W at the measured first measurement point P1, second measurement point P2, and third measurement point P3 after finish grinding are: thickness T11=102 μm, T12=100 μm, T13= It is assumed to be 101 μm.

(4) Polishing step for the first disk-shaped work Next, the disk-shaped work W, which has been ground to the finished thickness and whose back surface Wb has a higher flatness, is moved to below the polishing means 4, and as shown in FIG. As shown, the disk-shaped work W is polished as in the case of the first embodiment. Then, after the polishing of the first disk-shaped work W is completed, the polishing means 4 is moved in the +Z direction as shown in FIG.

(5) Measurement process for the first disk-shaped work After the rotation of the holding table 5 is stopped, the first measurement point P1 is provided immediately below the optical sensors 651, 652, 653 of the polishing thickness measurement means 67, respectively. The second measurement point P2 and the third measurement point P3 are located. Then, the thicknesses T21, T22, T23 of the disk-shaped workpiece W at the first measurement point P1, the second measurement point P2, and the third measurement point P3 are determined by the optical sensors 651, 652, 653 of the polishing thickness measuring means 67. Measure respectively. For example, the thickness T21=95 μm, T22=98 μm, and T23=97 μm. The number of measurement points may be only two, that is, the first measurement point P1 and the second measurement point P2.

(6) Calculation process for the first disk-shaped work For example, the CPU of the control means 9 measures the first measurement point P1, the second measurement point P2, and the third measurement point P2 shown in FIG. From the thickness T11=102 μm, T12=100 μm, T13=101 μm after the finish grinding of the first disk-shaped work W at the measurement point P3, the first measurement point P1 shown in FIG. The polishing removal amount L1=102 μm-95 μm at the three measurement points after subtracting the thicknesses T21=95 μm, T22=98 μm, and T23=97 μm after polishing of the disk-shaped workpiece W at the second measurement point P2 and the third measurement point P3. =7 μm, L2=100 μm-98 μm=2 μm, and L3=101 μm-97 μm=4 μm.

(7) Thickness tendency recognition step for the first disk-shaped work The optical sensors 651, 652, 653 of the polishing thickness measuring means 67 measure the first measurement point P1 and the second measurement point P1 of the disk-shaped work W. Information about the thicknesses T21, T22, T23 of the measurement point P2 and the third measurement point P3 is sent to the control means 9 shown in FIG. For example, since the measured thicknesses T21=95 μm, T22=98 μm, and T23=97 μm shown in FIG. 18, the thickness tendency recognizing unit 91 has a tendency that the disk-shaped workpiece W after polishing becomes thicker toward the outer side in the radial direction. In other words, it is determined that the disk-shaped work W after polishing tends to have a concave shape.

When the turntable 6 shown in FIG. 1 rotates in the counterclockwise direction when viewed from the +Z direction, the holding table 5 moves to the vicinity of the unloading arm 154b. Next, the unloading arm 154b conveys the disk-shaped work W from the holding table 5 to the cleaning means 156. The first disk-shaped work W that has been cleaned is accommodated in the second cassette 151a by the robot 155.

(8) Inclination changing step in the first disk-shaped work In the inclination changing step in the second embodiment, the thickness tendency recognized in the thickness tendency recognition step (the tendency of the first disk-shaped work W to be a concave shape). The disk-shaped work obtained by subtracting the polishing removal amounts L1=7 μm, L2=2 μm, and L3=4 μm at the first measurement point P1, the second measurement point P2, and the third measurement point P3 calculated in In order to form the disk-shaped work W (second disk-shaped work W) having a thickness tendency contrary to the thickness tendency of W in the next grinding step, the grinding wheels 304 of the rough grinding means 30 and the finish grinding means 31 are The tilt relationship between the mounted rotary shaft 300 and the rotary shaft 571 of the holding table 5 is changed. In the first disk-shaped work W, the thickness tendency obtained by subtracting the polishing removal amounts L1 to L3 from the thickness tendency of the three measurement points P1 to P3 recognized in the thickness tendency recognition step is as shown in FIG. The thickness tends to be more concave than the first disk-shaped work W after polishing and has a steeper slope. Therefore, the thickness tendency of the second disk-shaped work W (thickness tendency to be formed in the next grinding step), which is contrary to the thickness tendency obtained by subtracting the polishing removal amounts L1 to L3, has a convex shape as shown in FIG. Thickness tendency.

A specific example of changing the inclination relationship between the rotary shaft 300 on which the grinding wheel 304 of the rough grinding means 30 and the finish grinding means 31 is mounted and the rotary shaft 571 of the holding table 5 is shown in, for example, the control means shown in FIG. 9 shows the maximum polishing removal amount L1 among the polishing removal amounts L1=7 μm, L2=2 μm, and L3=4 μm at the first measurement point P1, the second measurement point P2, and the third measurement point P3. The difference (L1−L2=5 μm) from the minimum polishing removal amount L2 is calculated. Then, the difference becomes a correction value S1=5 μm for appropriately changing the inclination relationship between the rotary shaft 300 and the rotary shaft 571. In the present embodiment, as shown in FIG. 20, under the control of the control unit 9, the tilt changing unit 51 changes the tilt angle of the rotation shaft 571 of the holding table 5 (for example, holding on the outer peripheral side of the holding table 5). Raise the surface 50a by a predetermined distance) so that the thickness after finish grinding becomes a medium convexity 5 μm (correction value S1=5 μm), that is, the thickness after finish grinding at the first measurement point P1 is the desired finish thickness. 100 μm+5 μm (correction value S1)=105 μm.

(9) Holding process for second disc-shaped work to (10) Grinding process Holding process for disc-shaped work W to be newly ground (hereinafter, second disc-shaped work W) However, as in the case of the first disk-shaped work W, the disk-shaped work W is held by the holding table 5 as shown in FIG. Further, rough grinding and finish grinding in the grinding process are performed in the same manner as in the case of the first disk-shaped work W except that the inclination of the rotary shaft 571 of the holding table 5 is changed, as shown in FIG. As described above, the second disk-shaped work W after grinding is made to have a middle convex thickness tendency by grinding the disk-shaped work W so as to have a desired finished thickness (for example, 100 μm). You can

(11) Pre-polishing measurement step for second disk-shaped work Next, three points of the first measurement point P1 to the third measurement point P3 of the second disk-shaped work W shown in FIG. At, the thickness of the disk-shaped workpiece W after finish grinding is measured. After the rotation of the holding table 5 is stopped and the final grinding wheel 314b is separated from the disk-shaped work W, the first measurement points are measured by the optical sensors 651, 652, 653 of the final grinding thickness measuring means 66 shown in FIG. The thicknesses T31, T32, T33 of the disk-shaped work W at P1, the second measurement point P2, and the third measurement point P3 are measured. The number of measurement points may be only two, that is, the first measurement point P1 and the second measurement point P2.

The optical sensors 651, 652, 653 of the finish grinding thickness measuring means 66 measure the first measurement point P1, the second measurement point P2, and the thicknesses T31, T32 of the third measurement point P3 of the disk-shaped workpiece W measured. The information about T33 is sent to the control means 9 shown in FIG. For example, the thickness of the disk-shaped workpiece W at the measured first measurement point P1, second measurement point P2, and third measurement point P3 after finish grinding is as follows: thickness T31=105 μm, T32=100 μm, T33= The thickness is 102 μm, and the shape is medium convex.

(12) Polishing Step for Second Disc-Shaped Work Next, the disc-shaped work W, which has been ground to the finished thickness and whose back surface Wb has a higher flatness, moves to below the polishing means 4, and FIG. As shown, the polishing is performed in the same manner as the case of the first disk-shaped work W except that the inclination of the rotary shaft 571 of the holding table 5 is changed. Then, after the polishing of the second disk-shaped work W is completed, the polishing feed means 25 moves the polishing means 4 in the +Z direction and separates it from the polished disk-shaped work W.

(13) Measurement process for the second disk-shaped work After the rotation of the holding table 5 is stopped, the optical sensors 651, 652, 653 of the polishing thickness measuring means 67 are used to measure the first disc as shown in FIG. The thicknesses T41, T42, and T43 of the second disk-shaped work W at the measurement points P1, the second measurement points P2, and the third measurement points P3 of the optical sensors 651, 652, and 653 of the polishing thickness measuring means 67. Measure respectively. For example, assume that the thicknesses T41=98 μm, T42=98 μm, and T43=98 μm. The number of measurement points may be only two, that is, the first measurement point P1 and the second measurement point P2.

(14) Calculation process for the second disk-shaped work The CPU of the control means 9 measures the first measurement point P1, the second measurement point P2, and the third measurement point P1 measured in the pre-polishing measurement process shown in FIG. From the thickness T31=105 μm, T32=100 μm, T33=102 μm after the finish grinding of the first disk-shaped work W at the measurement point P3, the first measurement point P1 and the second measurement point P1 measured in the measurement process shown in FIG. The polishing removal amount L11=105 μm−98 μm=at three measurement points after subtracting the thickness T41=98 μm, T42=98 μm, T43=98 μm after polishing of the disk-shaped workpiece W at the measurement point P2 and the third measurement point P3. 7 μm, L12=100 μm−98 μm=2 μm, and L13=102 μm−98 μm=4 μm are calculated.

(15) Thickness tendency recognition step for the second disk-shaped work The optical sensors 651, 652, 653 of the polishing thickness measuring means 67 provide information on the measured thicknesses T41, T42, T43 shown in FIG. To the control means 9 shown in FIG. For example, the thickness of the disk-shaped workpiece W after polishing at the first measurement point P1, the second measurement point P2, and the third measurement point P3 is T41=98 μm, T42=98 μm, and T43=98 μm. The thickness tendency recognizing unit 91 determines that the disk-shaped work W after polishing is flat.
After that, the second disk-shaped work W is carried out from the holding table 5 and stored in the second cassette 151a shown in FIG.

In the disk-shaped workpiece processing method according to the present invention, at least three measurement points P1, P2, that is, a first measurement point P1, a second measurement point P2, and a third measurement point P3, for example, before the polishing step. , P3, the pre-polishing measurement step of measuring the thicknesses T11, T12, T13 of the disk-shaped workpiece W shown in FIG. 16 and the three measurement points P1 shown in FIG. 16 measured in the pre-polishing measurement step before the inclination changing step. , P2, P3, the thickness T21, T22, T23 of the disk-shaped work W at the three measurement points P1, P2, P3 shown in FIG. And a calculation step of calculating the polishing removal amounts L1, L2, and L3 at the three measurement points P1, P2, and P3 by subtracting the same. In the inclination changing step, the thickness tendency (first sheet One from which the polishing removal amounts L1 to L3 at the first measurement point P1, the second measurement point P2, and the third measurement point P3 calculated in the calculation process are subtracted from (the tendency of the disk-shaped work W to be concave) To form a new second disk-shaped work W having a thickness tendency (center-convex thickness tendency) contrary to the thickness tendency (center-concave thickness tendency) of the eye-shaped disk-shaped work W in the next grinding step. In addition, by changing the inclination relationship between the rotary shaft 300 on which the grinding wheel 304 is mounted and the rotary shaft 571 of the holding table 5, as shown in FIG. 22, the second disc-shaped work W is ground after the grinding process. It is possible to have a thickness tendency of a medium convex shape, and after polishing a new disc-shaped work W (second disc-shaped work W) after polishing the first disc-shaped work W. It becomes possible to flatten with high accuracy.

As in the present embodiment, in the pre-polishing measurement step, at least two measurement points P1 and P2 and a third measurement point P3 that is an intermediate point between the first measurement point P1 and the second measurement point P2 are included. The thicknesses T11 to T13 of the disk-shaped work W are measured at three measurement points P3, the thickness T21 to T23 of the disk-shaped work W is measured at at least three measurement points P1 to P3 in the measurement step, and the calculation step is performed. From the thicknesses T11 to T13 of the disk-shaped work W at the three measurement points P1 to P3 measured in the pre-polishing measurement step, the thicknesses T21 to T23 of the disk-shaped work W at the three measurement points P1 to P3 measured in the measurement step Is calculated to calculate the polishing removal amounts L1 to L3 at the three measurement points P1 to P3, and in the thickness tendency recognition step, the thickness of the disk-shaped workpiece W after polishing at least at the three measurement points P1 to P3 is changed to a disk shape. By recognizing the thickness tendency of the work W in the radial direction, the inclination can be more appropriately adjusted in the inclination changing step than in the case where there are only two measurement points, the first measurement point P1 and the second measurement point P2. It is possible to change the relationship.

(16) Inclination changing step in the second disk-shaped work In the inclination changing step in the second embodiment, the thickness tendency recognized in the thickness tendency recognition step (the second disk-shaped workpiece W after polishing is flat). Disk obtained by subtracting the polishing removal amounts L11=7 μm, L12=2 μm, and L13=4 μm at the first measurement point P1, the second measurement point P2, and the third measurement point P3 calculated in the calculation step In order to form the third disc-shaped work W having a thickness tendency (thickness tendency of a medium concave shape) contrary to the thickness tendency of the work piece W (thickness tendency of a concave shape), a rough grinding means 30 is formed. Also, the inclination relationship between the rotary shaft 300 on which the grinding wheel 304 of the finish grinding means 31 is mounted and the rotary shaft 571 of the holding table 5 is changed.

Specifically, for example, by the control means 9, the polishing removal amounts L11=7 μm, L12=2 μm, and L13=4 μm at the first measurement point P1, the second measurement point P2, and the third measurement point P3. The difference (L11−L12=5 μm) between the maximum polishing removal amount L11 and the minimum polishing removal amount L12 is calculated. Then, the difference becomes a correction value S2=5 μm for appropriately changing the inclination relationship between the rotary shaft 300 and the rotary shaft 571. Since the correction value S2=5 μm is the same value as the correction value S1=5 μm calculated in the inclination changing step of the first disk-shaped work W, the rotary shaft 300 on which the grinding wheel 304 is mounted and the holding table. The inclination relationship between the rotation axis 571 and the rotation axis 571 of 5 is maintained as shown in FIG. 25, and the thickness after the finish grinding of the first measurement point P1 of the third disk-shaped workpiece W is the second circle. The same desired finished thickness as the plate-shaped workpiece W is set to 100 μm+5 μm (correction value S2)=105 μm.

(17) Holding step for the third disk-shaped work to (18) Grinding step Holding step for the disk-shaped work W to be newly ground (hereinafter, the third disk-shaped work W) Is performed in the same manner as for the second disk-shaped work W, and the disk-shaped work W is held by the holding table 5 as shown in FIG. Further, similarly to the case of the second disk-shaped work W, rough grinding and finish grinding are performed so that the disk-shaped work W has a desired finish thickness (for example, 100 μm), and thus, after the grinding, The thickness tendency of the third disk-shaped work W can be made to have a convex shape.

(19) Pre-polishing measurement step for third disk-shaped work Next, the first measurement point P1, the second measurement point P2, and the third measurement point P3 of the third sheet shown in FIG. The thickness of the disk-shaped work W after finish grinding is measured at at least three points. After the rotation of the holding table 5 is stopped and the final grinding wheel 314b is separated from the disk-shaped work W, the first measurement points are measured by the optical sensors 651, 652, 653 of the final grinding thickness measuring means 66 shown in FIG. The thicknesses T51, T52, T53 of the disk-shaped work W at P1, the second measurement point P2, and the third measurement point P3 are measured.
The optical sensors 651, 652, 653 of the finish grinding thickness measuring means 66 send information about the measured thicknesses T51, T52, T53 to the control means 9 shown in FIG. For example, the measured thickness is T51=105 μm, T52=100 μm, and T53=102 μm.

(20) Polishing Step for Third Disc-Shaped Work Next, the disc-shaped work W ground to the finished thickness moves to below the polishing means 4, and as shown in FIG. The polishing is performed as in the case of the plate-shaped work W. Then, after the polishing of the third disk-shaped work W is completed, the polishing feeding means 25 moves the polishing means 4 in the +Z direction to separate it from the polished disk-shaped work W.

(21) Measuring Step for Third Disc-shaped Work After the rotation of the holding table 5 is stopped, as shown in FIG. 29, by the optical sensors 651, 652, 653 of the polishing thickness measuring means 67, the first The thicknesses T61, T62, T63 of the third disk-shaped work W at the measurement point P1, the second measurement point P2, and the third measurement point P3 are measured, respectively. For example, the thickness T61=97.9 μm, the thickness T62=98 μm, and the thickness T63=98 μm.

(22) Calculation process for the third disk-shaped work For example, the CPU of the control means 9 measures the first measurement point P1, the second measurement point P2, and the third measurement point P1 measured in the pre-polishing measurement process shown in FIG. From the thickness T51=105 μm, T52=100 μm, T53=102 μm after the finish grinding of the third disk-shaped work W at the measurement point P3, the first measurement point P1 measured at the measurement step shown in FIG. The polishing removal amount L21=105 μm at the three measurement points after subtracting the thicknesses T61=97.9 μm, T62=98 μm, and T63=98 μm of the disk-shaped workpiece W after the polishing at the second measurement point P2 and the third measurement point P3. Calculate -97.9 μm=7.1 μm, L22=100 μm-98 μm=2 μm, and L23=102 μm-98 μm=4 μm.

(23) Step of recognizing the thickness tendency of the third disk-shaped work The measured thickness of the disk-shaped work W after polishing is, as shown in FIG. 29, thickness T61=97.9 μm, T62=98 μm, T63. =98 μm, the thickness tendency recognition unit 91 determines that the disk-shaped workpiece W after polishing has a slightly concave shape. That is, it is determined that the flatness of the disk-shaped workpiece W after polishing is slightly lowered due to the change in the polishing removal amount due to the deformation of the polishing pad 44 or the like.
After that, the third disk-shaped work W is carried out from the holding table 5 and accommodated in the second cassette 151a shown in FIG.

(24) Inclination changing process in the third disk-shaped work In the inclination changing process in the second embodiment, the thickness tendency recognized in the thickness tendency recognition step (the third disk-shaped work W is slightly concaved). The tendency of the polishing removal) to subtract the polishing removal amount L21=7.1 μm, L22=2 μm, and L23=4 μm at the first measurement point P1, the second measurement point P2, and the third measurement point P3 calculated in the calculation step. Next, a disk-shaped work W (fourth disk-shaped work W) having a thickness tendency (center-convex thickness tendency) contrary to the thickness tendency (center-concave thickness tendency) of the third disk-shaped work W is next described. In order to form it in the grinding process of No. 3, the tilt relationship between the rotary shaft 300 on which the grinding wheels 304 of the rough grinding unit 30 and the finish grinding unit 31 are mounted and the rotary shaft 571 of the holding table 5 is changed.

Specifically, for example, the controller 9 controls the difference (L21) between the maximum polishing removal amount L21 and the minimum polishing removal amount L22 among the polishing removal amounts L21=7.1 μm, L22=2 μm, and L23=4 μm. -L22=5.1 μm) is calculated. The difference is that the first measurement point P1 at the center of the third disk-shaped work W after polishing is increased by 0.1 μm and is more likely to be polished than the second disk-shaped work W. In contrast to this, the correction value S3 for appropriately changing the inclination relationship between the rotary shaft 300 and the rotary shaft 571 is 5.1 μm.

In the second embodiment, under the control of the control unit 9, the tilt changing unit 51 changes the tilt angle of the rotary shaft 571 of the holding table 5 (for example, the holding surface 50a on the outer peripheral side of the holding table 5 is raised by a predetermined distance. Change) so that the thickness of the next disc-shaped workpiece W after finish grinding becomes a medium convex of 5.1 μm (correction value S3=5.1 μm), that is, the fourth disc. The thickness of the workpiece W after the first grinding at the first measurement point P1 is set to a desired finished thickness of 100 μm+5.1 μm (correction value S3)=105.1 μm. As a result, unlike the third disk-shaped work W in which the flatness is slightly different after polishing as shown in FIG. 29 due to the change in the polishing removal amount due to the deformation of the polishing pad 44, etc. After the grinding process of the fourth disk-shaped work W, the processing conditions are corrected so as to follow the change in the polishing removal amount so that the flatness of the disk-shaped work W after polishing is not different. The thickness tendency of can be changed appropriately.

As a result, the next fourth disk-shaped work W can be formed to have a thickness tendency of a medium convex shape after the grinding step, and further, the next fourth disk-shaped work W is ground three times. After polishing, the second disk-shaped work W is flattened more accurately than the disk-shaped work W, that is, the fourth disk-shaped work W at the first measurement point P1, the second measurement point P2, and the third measurement point P3. It is possible to make the thickness after polishing of, for example, 98 μm as in the case of the second disk-shaped work W.

It goes without saying that the method for processing a disk-shaped work according to the present invention is not limited to the above-described first or second embodiment, and may be carried out in various different forms within the scope of its technical idea. Further, each configuration of the grinding and polishing apparatus 1 shown in the accompanying drawings is not limited to this, and can be appropriately changed within a range where the effect of the present invention can be exhibited.

W: Disc-shaped work 1: Grinding/polishing device 10: First device base A: Loading/unloading area
150: 1st cassette mounting part 150a: 1st cassette 151: 2nd cassette mounting part 151a: 2nd cassette 152: Temporary mounting area 153: Positioning means 154a: Loading arm
154b: unloading arm 155: robot 156: cleaning means 11: second device base B: processing area
12: 1st column 20: Coarse grinding feed means 30: Coarse grinding means 304b: Coarse grinding wheel 13: 2nd column 21: Finishing grinding feeding means 31: Finishing grinding means 314b: Finishing grinding wheel 14: 3rd column 24: Y-axis direction moving means 25: Polishing feeding means 4: Polishing means 6: Turntable
64: Support base 65: Coarse grinding thickness measuring means 650: Arm part 659: Moving means 651-653: Optical sensor 66: Finish grinding thickness measuring means 67: Polishing thickness measuring means 5: Holding table 50: Porous member 50a: Holding surface 502: Frame body
51: Inclination adjusting means 52: Support base 520: Support cylinder part 521: Flange part 53: Position adjustment unit 531: Cylinder part 532: Shaft 532a: First male screw 533: Drive part 533a: Motor 533b: Reduction gear 534: Fixed Part 535: Nut 536: Holding nut 53a: Fixed unit 57: Holding table rotating means 571: Rotating shaft 571b: Piping 572: Motor 573: Pulley 574: Endless belt 9: Control means 90: Storage part 91: Thickness tendency recognizing part

Claims (4)

A method of processing a disk-shaped work, comprising grinding a disk-shaped work held on a holding surface of a holding table with a grinding wheel and polishing with a polishing pad,
A holding step of holding the disk-shaped work on the holding table;
A grinding step of rotating the disk-shaped work and a grinding wheel, respectively, and grinding the disk-shaped work with the grinding wheel;
After the grinding step, a polishing step of rotating the disk-shaped work and the polishing pad respectively and polishing with the polishing pad covering the disk-shaped work,
After the polishing step, the thickness of the disc-shaped work at at least two measurement points, a first measurement point at the center of the disc-shaped work and a second measurement point near the outer peripheral edge of the disc-shaped work. A measurement process for measuring
A thickness tendency recognizing step of recognizing a thickness tendency in the radial direction of the disk-shaped work from the thicknesses of the disk-shaped work at the two measurement points measured in the measurement step;
In the next grinding step, in order to form a disk-shaped work having a thickness tendency contrary to the thickness tendency recognized in the thickness tendency recognition step, a rotary shaft on which the grinding wheel is mounted and a rotary shaft of the holding table are formed. A method of processing a disk-shaped workpiece, comprising a tilt changing step of changing a tilt relationship. In the measuring step, at least three measuring points of the two measuring points and a third measuring point which is an intermediate point between the first measuring point and the second measuring point of the disk-shaped workpiece Measure the thickness,
2. The method for processing a disk-shaped work according to claim 1, wherein in the thickness tendency recognition step, a thickness tendency in the radial direction of the disk-shaped work is recognized from the thickness of the disk-shaped work at least at the three measurement points. A pre-polishing measurement step of measuring the thickness of the disk-shaped workpiece at at least two measurement points of the first measurement point and the second measurement point before the polishing step;
Prior to the inclination changing step, the thickness of the disk-shaped work at the two measurement points measured in the measurement step is subtracted from the thickness of the disk-shaped work at the two measurement points measured in the pre-polishing measurement step. And a calculation step of calculating the polishing removal amount at the two measurement points,
In the inclination changing step, a disc-shaped work having a thickness tendency contrary to the thickness tendency of the disc-shaped work obtained by subtracting the polishing removal amount from the thickness tendency recognized in the thickness tendency recognition step is formed in the next grinding step. The method for machining a disk-shaped workpiece according to claim 1, wherein the tilt relationship between the rotary shaft on which the grinding wheel is mounted and the rotary shaft of the holding table is changed. In the pre-polishing measurement step, the disk shape is formed at at least three measurement points of the two measurement points and a third measurement point which is an intermediate point between the first measurement point and the second measurement point. Measure the work thickness,
In the measuring step, the thickness of the disk-shaped work is measured at least at the three measuring points,
In the calculation step, the thickness of the disc-shaped work at the three measurement points measured in the measurement step is subtracted from the thickness of the disc-shaped work at the three measurement points measured in the pre-polishing measurement step. Calculate the polishing removal amount at three measurement points,
4. The method for processing a disk-shaped work according to claim 3, wherein in the thickness tendency recognition step, the thickness tendency in the radial direction of the disk-shaped work is recognized from the thickness of the disk-shaped work at least at the three measurement points.

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