POLISHING APPARATUS AND METHOD OF POLISHING WORKPIECE

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Japanese Patent Application No. 2024-210005 filed with the Japan Patent Office on Dec. 3, 2024, the entire content of which is hereby incorporated by reference.

BACKGROUND ART

1. Technical Field

The present invention relates to a polishing apparatus and a method of polishing a workpiece.

2. Related Art

As disclosed in Japanese Unexamined Patent Publication No. 2012-106293, according to a method of polishing a workpiece, a rotating workpiece is polished by rotating a polishing pad that is sized to entirely cover the workpiece. Because an outer circumferential part of the workpiece is less easily polished as compared to a central part of the workpiece in this polishing, a thickness variation tends to exist in the workpiece after the polishing. Due to this, the polishing is performed while the workpiece and the polishing pad are moved in the horizontal direction relative to each other.

SUMMARY

According to a technology disclosed in Japanese Unexamined Patent Publication No. 2015-188975, a polishing surface of a polishing pad is dressed in accordance with the shape of a workpiece. However, because the polishing pad is significantly worn by such dressing, the polishing pad must be frequently replaced and cost increase is incurred.

An object of the present invention is therefore to polish a workpiece to an even thickness with reduced costs.

A polishing apparatus (present polishing apparatus) of the present invention includes: a chuck table which holds a workpiece; a polishing mechanism to which a polishing tool configured to polish the workpiece is attached and which is configured to rotate the polishing tool; an elevation mechanism which is configured to move up and down the chuck table and the polishing tool relative to each other in a vertical direction; and a horizontal movement mechanism which is configured to move the chuck table and the polishing tool relative to each other in a horizontal direction, the polishing tool being a polishing roll that has an outer side surface used for polishing the workpiece and is hollow cylindrical or solid cylindrical in shape, and the polishing mechanism including a spindle unit to which the polishing roll is attached and which rotates about a rotational axis whose longitudinal direction is the horizontal direction so as to rotate the polishing roll about the rotational axis.

The present polishing apparatus may further include a polishing liquid nozzle which is configured to supply polishing liquid to the polishing roll.

The present polishing apparatus may further include a tilt adjustment mechanism which is configured to adjust tilt of the rotational axis of the polishing roll relative to the workpiece held by the chuck table.

A first method of polishing a workpiece of the present invention (first polishing method) is a method of polishing a workpiece by using the present polishing apparatus, which includes: a holding step of holding the workpiece by the chuck table; and a partial polishing step of, after the holding step, polishing a part of a top surface of the workpiece by bringing the polishing roll into contact with a predetermined part of the workpiece while causing the horizontal movement mechanism to move the chuck table and the polishing roll in the horizontal direction relative to each other.

A second method of polishing a workpiece of the present invention (second polishing method) is a method of polishing a workpiece by using the present polishing apparatus, which includes: a holding step of holding the workpiece by the chuck table; and an entire polishing step of, after the holding step, polishing entirety of a top surface of the workpiece by bringing the polishing roll into contact with the workpiece while causing the horizontal movement mechanism to move the chuck table and the polishing roll in the horizontal direction relative to each other.

According to the second polishing method, the entire polishing step may include polishing of the entirety of the top surface of the workpiece by causing the horizontal movement mechanism to linearly move the chuck table in the horizontal direction relative to the polishing roll while relatively reciprocating the polishing roll in a direction intersecting with the direction of linear movement.

The second polishing method may further include: a measuring step of measuring overall thickness of the workpiece after the entire polishing step; and a partial polishing step of, after the measuring step, polishing a thick part of the workpiece by bringing the polishing roll into contact with the thick part that is thicker than a predetermined value in the workpiece, while causing the horizontal movement mechanism to move the chuck table and the polishing roll in the horizontal direction relative to each other.

According to the present invention, the top surface of the workpiece can be polished by bringing the polishing roll into contact with the workpiece while horizontally moving the chuck table and the polishing roll relative to each other. In other words, the top surface of the workpiece is polished part by part by the polishing roll. It is therefore unnecessary to dress the polishing surface (outer side surface) of the polishing roll in accordance with the workpiece. Because the polishing roll is not worn by the dressing, the frequency of replacement of the polishing roll is reduced. As a result, it is possible to polish the workpiece to an even thickness while suppressing costs for the polishing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an oblique perspective view showing an arrangement of a polishing apparatus.

FIG. 2 is a cross-sectional view illustrating a holding step.

FIG. 3 is a cross-sectional view illustrating an entire polishing step and a partial polishing step.

FIG. 4 is a cross-sectional view illustrating a Z-axis moving mechanism having a tilt adjustment mechanism.

FIG. 5 is a cross-sectional view illustrating another entire polishing step and another partial polishing step.

DETAILED DESCRIPTION

In the following detailed description, for purpose of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing.

As shown in FIG. 1, a polishing apparatus 1 of the present embodiment is an apparatus configured to polish a workpiece 100 held by a chuck table 20 by using a polishing roll 74. The workpiece 100 is, for example, circular or rectangular in shape, and a protection tape 105 is pasted onto the bottom surface of the workpiece 100.

The polishing apparatus 1 includes an apparatus base 10 which is rectangular parallelepiped in shape, a column 11 extending upward, and a controller 7 configured to control components of the polishing apparatus 1.

In the apparatus base 10, an opening 13 is formed on the top surface side. In the opening 13, a workpiece holding mechanism 30 is provided.

The workpiece holding mechanism 30 includes the chuck table 20 which holds the workpiece 100, a chuck table base 29 which supports the chuck table 20, a rotating mechanism 26 which is connected to the base end side of the chuck table base 29 through an endless belt 25, a supporter 28 which supports the chuck table base 29, and supporting pillars 27 which support the supporter 28.

As shown in FIG. 2, the chuck table 20 has a frame 23, and a holder 21 made of a porous member is provided in a recess in the frame 23. The top surface of the holder 21 is the holding surface 22 arranged to suck and hold the workpiece 100. Due to communication with a suction source (not illustrated), the holding surface 22 sucks and holds the protection tape 105 side of the workpiece 100.

The rotating mechanism 26 includes a motor 261 and a drive pulley 262, and is configured to rotate the chuck table base 29 by rotating the endless belt 25. With this arrangement, the chuck table 20 supported by the chuck table base 29 rotates about a table rotational axis which passes through the center of the holding surface 22.

The rotating mechanism 26 includes an encoder 263. The encoder 263 is rotated as the motor 261 of the rotating mechanism 26 rotates the chuck table 20. The encoder 263 is able to recognize the rotation amount (rotation count and rotation angle) of the chuck table 20.

On the bottom surface of the chuck table 20, a cover plate 39 is provided to move along a Y-axis direction together with the chuck table 20. The cover plate 39 is connected to a bellows cover 12 which expands and contracts in the Y-axis direction. Below the workpiece holding mechanism 30, a Y-axis movement mechanism 40 is provided.

The Y-axis movement mechanism 40 is configured to move the chuck table 20 and the polishing roll 74 of a polishing mechanism 70 relative to each other in the Y-axis direction (horizontal direction) which is parallel to the holding surface 22. The Y-axis movement mechanism 40 is an example of a horizontal movement mechanism. In the present embodiment, the Y-axis movement mechanism 40 is configured to move the workpiece holding mechanism 30 including the chuck table 20 in the Y-axis direction relative to the polishing mechanism 70.

The Y-axis movement mechanism 40 includes a pair of Y-axis guide rails 42 which are parallel to the Y-axis direction, a Y-axis movement table 45 which slides on these Y-axis guide rails 42, a Y-axis ball screw 43 which is parallel to the Y-axis guide rails 42, a Y-axis motor 44 which is connected to the Y-axis ball screw 43, a Y-axis encoder 46 configured to detect the rotation amount of the Y-axis ball screw 43, and a holding base 41 which holds the foregoing members.

The Y-axis movement table 45 is provided on the Y-axis guide rails 42 to be slidable. To the Y-axis movement table 45, a nut (not illustrated) is fixed. Into this nut, the Y-axis ball screw 43 is screwed. The Y-axis motor 44 is connected to one end portion of the Y-axis ball screw 43.

In the Y-axis movement mechanism 40, as the Y-axis motor 44 rotates the Y-axis ball screw 43, the Y-axis movement table 45 moves in the Y-axis direction along the Y-axis guide rails 42. On the Y-axis movement table 45, the workpiece holding mechanism 30 is placed. On this account, in accordance with the movement of the Y-axis movement table 45 in the Y-axis direction, the workpiece holding mechanism 30 including the chuck table 20 moves in the Y-axis direction.

The Y-axis encoder 46 of the Y-axis movement mechanism 40 is rotated as the Y-axis motor 44 rotates the Y-axis ball screw 43, and the Y-axis encoder 46 is able to recognize the rotation amount (rotation count and rotation angle) of the Y-axis ball screw 43. In the present embodiment, the controller 7 is able to detect the position in the Y-axis direction of the chuck table 20 based on the rotation amount of the Y-axis ball screw 43 recognized by the Y-axis encoder 46.

At a rear part (on the +Y direction side) of the top surface of the apparatus base 10, the column 11 is erected. On the front surface of the column 11, the polishing mechanism 70 configured to polish the workpiece 100, a Z-axis moving mechanism 60 configured to move the polishing mechanism 70 in the Z-axis direction, and an X-axis movement mechanism 50 configured to move the polishing mechanism 70 and the Z-axis moving mechanism 60 in the X-axis direction are provided.

The X-axis movement mechanism 50 is configured to move the chuck table 20 and the polishing roll 74 of the polishing mechanism 70 relative to each other in the X-axis direction (horizontal direction) which is parallel to the holding surface 22. The X-axis movement mechanism 50 is an example of a horizontal movement mechanism. In the present embodiment, the X-axis movement mechanism 50 is configured to move the polishing mechanism 70 including the polishing roll 74 and the Z-axis moving mechanism 60 in the X-axis direction relative to the chuck table 20.

The X-axis movement mechanism 50 includes a pair of X-axis guide rails 51 which are parallel to the X-axis direction, an X-axis movement table 53 which slides on these X-axis guide rails 51, an X-axis ball screw 52 which is parallel to the X-axis guide rails 51, an X-axis motor 54 which is connected to the X-axis ball screw 52, and an X-axis encoder 55 which is configured to detect the rotation amount of the X-axis ball screw 52. To the X-axis movement table 53, the Z-axis moving mechanism 60 and the polishing mechanism 70 are attached.

The X-axis movement table 53 is provided on the X-axis guide rails 51 to be slidable. To the X-axis movement table 53, a nut (not illustrated) is fixed. Into this nut, the X-axis ball screw 52 is screwed. The X-axis motor 54 is connected to one end portion side of the X-axis ball screw 52.

In the X-axis movement mechanism 50, as the X-axis motor 54 rotates the X-axis ball screw 52, the X-axis movement table 53 moves in the X-axis direction along the X-axis guide rails 51. As a result, the Z-axis moving mechanism 60 attached to the X-axis movement table 53 and the polishing mechanism 70 supported by the Z-axis moving mechanism 60 move in the X-axis direction together with the X-axis movement table 53.

The X-axis encoder 55 of the X-axis movement mechanism 50 is rotated as the X-axis motor 54 rotates the X-axis ball screw 52, and the X-axis encoder 55 is able to recognize the rotation amount (rotation count and rotation angle) of the X-axis ball screw 52. In the present embodiment, the controller 7 is able to detect the position in the X-axis direction of the polishing roll 74 of the polishing mechanism 70 based on the rotation amount of the X-axis ball screw 52 recognized by the X-axis encoder 55.

The Z-axis moving mechanism 60 is an example of an elevation mechanism, and is configured to move up and down the chuck table 20 and the polishing roll 74 of the polishing mechanism 70 relative to each other in the Z-axis direction (vertical direction) perpendicular to the holding surface 22. In the present embodiment, the Z-axis moving mechanism 60 is configured to move up and down the polishing mechanism 70 including the polishing roll 74 in the Z-axis direction relative to the chuck table 20.

The Z-axis moving mechanism 60 includes a pair of Z-axis guide rails 61 which are parallel to the Z-axis direction, a Z-axis movement table 63 which slides on these Z-axis guide rails 61, a Z-axis ball screw 62 which is parallel to the Z-axis guide rails 61, a Z-axis motor 64 which is connected to the Z-axis ball screw 62, and a Z-axis encoder 65 which is configured to detect the rotation amount of the Z-axis ball screw 62. To the Z-axis movement table 63, the polishing mechanism 70 is attached.

The Z-axis movement table 63 is provided on the Z-axis guide rails 61 to be slidable. To the Z-axis movement table 63, a nut (not illustrated) is fixed. Into this nut, the Z-axis ball screw 62 is screwed. The Z-axis motor 64 is connected to one end portion of the Z-axis ball screw 62.

In the Z-axis moving mechanism 60, as the Z-axis motor 64 rotates the Z-axis ball screw 62, the Z-axis movement table 63 moves in the Z-axis direction along the Z-axis guide rails 61. As a result, the polishing mechanism 70 attached to the Z-axis movement table 63 moves in the Z-axis direction together with the Z-axis movement table 63.

The Z-axis encoder 65 of the Z-axis moving mechanism 60 is rotated as the Z-axis motor 64 rotates the Z-axis ball screw 62, and the Z-axis encoder 65 is able to recognize the rotation amount (rotation count and rotation angle) of the Z-axis ball screw 62. In the present embodiment, the controller 7 is able to detect the position in the Z-axis direction of the polishing roll 74 of the polishing mechanism 70 based on the rotation amount of the Z-axis ball screw 62 recognized by the Z-axis encoder 65.

A polishing tool for polishing the workpiece 100 is attached to the polishing mechanism 70, and the polishing mechanism 70 rotates the polishing tool to polish the workpiece 100 held by the chuck table 20. The polishing mechanism 70 includes a base 71 which is fixed to the Z-axis movement table 63, a spindle 72 which is rotatably held by the base 71, a spindle motor 73 which is configured to rotationally drive the spindle 72, the polishing roll 74 which is a polishing tool attached to the leading end of the spindle 72, a polishing liquid nozzle 76 used for supplying polishing liquid to the polishing roll 74, and a nozzle shaft 77 which supports the polishing liquid nozzle 76.

The spindle 72 extends in the Y-axis direction to be parallel to the holding surface 22 of the chuck table 20, and is rotatably supported by the base 71.

The spindle motor 73 is connected to the base end side of the spindle 72. This spindle motor 73 rotates the spindle 72 about a rotational axis 721 (see FIG. 2) passing through the center of the spindle 72 and extending in the Y-axis direction.

In this way, the spindle 72 includes a spindle unit to which the polishing roll 74 is attached and which rotates about a rotational axis 721 whose longitudinal direction is a horizontal direction so as to rotate the polishing roll 74 about the rotational axis.

The polishing roll 74 is an example of the polishing tool and is hollow cylindrical or solid cylindrical in shape. The polishing roll 74 is sized to be accommodated in the workpiece 100. The lengths in the X-axis direction and the Y-axis direction of the polishing roll 74 are shorter than those of the workpiece 100. The polishing roll 74 is, on its outer side surface, provided with a material for polishing the workpiece 100, and is attached to the leading end of the spindle 72. The polishing roll 74 is rotated by the spindle motor 73 together with the spindle 72, and polishes the workpiece 100 as the outer side surface of the polishing roll 74 makes contact with the workpiece 100 held by the chuck table 20. In this way, in the polishing apparatus 1, the polishing roll 74 has the outer side surface for polishing the workpiece 100, and the workpiece 100 is polished by the outer side surface of the rotating polishing roll 74.

The nozzle shaft 77 is supported by the base 71 to extend in the Y-axis direction along the spindle 72. At the leading end of the nozzle shaft 77, a polishing liquid nozzle 76 is attached to supply polishing liquid to the polishing roll 74. The polishing liquid nozzle 76 is connected to a polishing liquid supply source 78 (see FIG. 2), and supplies the polishing liquid to the polishing roll 74 when the workpiece 100 is polished by the polishing roll 74.

Beside the opening 13 of the apparatus base 10, a contactless thickness measuring mechanism 80 is provided.

The thickness measuring mechanism 80 includes a contactless thickness measurement device 82 configured to measure the thickness of the workpiece 100, an arm portion 83 supporting the contactless thickness measurement device 82 at the leading end, and a supporter 81 capable of supporting and rotating the arm portion 83. The supporter 81 allows the contactless thickness measurement device 82 to rotationally move to pass through the center of the holding surface 22 of the chuck table 20.

The contactless thickness measurement device 82 is configured to measure the thickness of the workpiece 100 held by the chuck table 20 in a contactless manner. For example, the contactless thickness measurement device 82 measures the thickness of the workpiece 100 by means of spectral interference in such a way that measurement light having a transmissive wavelength is applied to the workpiece 100 from above the workpiece 100 and top-surface-reflected light reflected on the top surface of the workpiece 100 and bottom-surface-reflected light reflected on the bottom surface of the workpiece 100 are received.

It is noted that the contactless thickness measurement device 82 is not limited to the above-described device configured to measure the thickness of the workpiece 100 by means of spectral interference. The contactless thickness measurement device 82 may measure the thickness of the workpiece 100 by means of ultrasound. The thickness measuring mechanism 80 is not limited to the above-described device configured to measure the thickness of the workpiece 100 in a contactless manner. The thickness measuring mechanism 80 may be arranged to calculate the thickness of the workpiece 100 in such a way that the height of the top surface of the workpiece 100 and the height of the top surface of the chuck table 20 are measured and the thickness of the workpiece 100 is calculated based on a difference between the calculated heights.

The controller 7 includes members such as a CPU configured to perform computation based on a control program and storage media such as a memory. The controller 7 controls the above-described members of the polishing apparatus 1 so as to centrally control components of the polishing apparatus 1. For example, the controller 7 controls the above-described members of the polishing apparatus 1 so as to polish the workpiece 100.

The following will describe a method of polishing the workpiece 100 of the present embodiment.

[Holding Step]

In the polishing method of the present embodiment, to begin with, a holding step is performed. In this step, the workpiece 100 is held by the chuck table 20. To be more specific, as shown in FIG. 2, an operator or an unillustrated transportation device places the workpiece 100 on the holding surface 22 of the chuck table 20 of the polishing apparatus 1 with the protection tape 105 facing down. Thereafter, as the controller 7 of the polishing apparatus 1 causes the holding surface 22 to communicate with the suction source, the workpiece 100 is sucked and held by the holding surface 22.

[Entire Polishing Step]

After the holding step, an entire polishing step is performed. In this process, the entirety of the top surface of the workpiece 100 is polished by bringing the polishing roll 74 into contact with the workpiece 100 while causing the horizontal movement mechanism to move the chuck table 20 holding the workpiece 100 and the polishing roll 74 in the horizontal direction relative to each other.

To be more specific, the polishing roll 74 is positioned above a polishing start position on the top surface of the workpiece 100 held by the chuck table 20, as the controller 7 controls the Y-axis movement mechanism 40 and the X-axis movement mechanism 50 to adjust the positions in the horizontal direction of the chuck table 20 and the polishing roll 74. This polishing start position on the top surface of the workpiece 100 is, for example, one end portion of an edge portion on the +Y direction side of the top surface of the workpiece 100 (i.e., one end portion in the X-axis direction).

Subsequently, the controller 7 rotates the polishing roll 74 by rotating the spindle 72 by using the spindle motor 73 of the polishing mechanism 70. Thereafter, the controller 7 lowers the polishing roll 74 by using the Z-axis moving mechanism 60 so as to bring the outer side surface of the rotating polishing roll 74 into contact with the top surface of the workpiece 100 and to polish the contact part, as shown in FIG. 3. At this stage, the controller 7 starts the supply of the polishing liquid from the polishing liquid nozzle 76 to the polishing roll 74.

Furthermore, the controller 7 polishes the entirety of the top surface of the workpiece 100 by causing the horizontal movement mechanism to linearly move the chuck table 20 in the horizontal direction relative to the polishing roll 74, while relatively reciprocating the polishing roll in a direction intersecting with the direction of the linear movement.

To be more specific, the controller 7 causes the Y-axis movement mechanism 40 to linearly move the chuck table 20 relative to the polishing roll 74 in the Y-axis direction (e.g., +Y direction) that is the horizontal direction, while causing the X-axis movement mechanism 50 to reciprocate the polishing roll 74 between one end portion and the other end portion in the X-axis direction of the top surface of the workpiece 100 along the X-axis direction intersecting with the Y-axis direction. As the polishing roll 74 runs zigzag while being in contact with the top surface of the workpiece 100, the top surface of the workpiece 100 is polished.

When the entirety of the top surface of the workpiece 100 is polished by the polishing roll 74, the controller 7 stops the movement of the chuck table 20 and the polishing roll 74. Furthermore, the controller 7 stops the supply of the polishing liquid from the polishing liquid nozzle 76 and causes the Z-axis moving mechanism 60 to move up the polishing roll 74, and finishes the entire polishing step.

[Measuring Step]

After the entire polishing step, a measuring step is performed. In this step, the overall thickness of the workpiece 100 is measured.

To be more specific, the controller 7 controls the Y-axis movement mechanism 40 to position the chuck table 20, which holds the workpiece 100 having been subjected to the entire polishing step, at a position below the thickness measuring mechanism 80 shown in FIG. 1. Subsequently, the controller 7 causes the rotating mechanism 26 to rotate the chuck table 20 and causes the supporter 81 of the thickness measuring mechanism 80 to rotationally move the contactless thickness measurement device 82 to pass through the center of the holding surface 22 of the chuck table 20. In this way, the controller 7 measures the overall thickness of the workpiece 100 by the contactless thickness measurement device 82 while changing the position of the contactless thickness measurement device 82 relative to the top surface of the workpiece 100, and stores thickness distribution of the workpiece 100 as a measurement result.

[Partial Polishing Step]

After the measuring step, a partial polishing step is performed. In this step, the controller 7 polishes a thick part of the workpiece 100 by bringing the polishing roll 74 into contact with a part thicker than a predetermined value in the workpiece 100 while causing the horizontal movement mechanism to move the chuck table 20 and the polishing roll 74 in the horizontal direction relative to each other.

To be more specific, to begin with, the controller 7 specifies the position of a part (polishing target part) which is thicker than a predetermined value (predetermined thickness value) in the workpiece 100, based on the thickness distribution of the workpiece 100 obtained in the measuring step. Thereafter, the controller 7 positions the polishing roll 74 above one polishing target part of the workpiece 100 held by the chuck table 20 by controlling the Y-axis movement mechanism 40 and the X-axis movement mechanism 50 to adjust the positions in the horizontal direction of the chuck table 20 and the polishing roll 74.

Then the controller 7 polishes (re-polishes) the one polishing target part of the workpiece 100 to have the same thickness as the other parts of the workpiece 100 by starting the supply of the polishing liquid from the polishing liquid nozzle 76 and moving down the polishing roll 74 while rotating the polishing roll 74. In this way, the controller 7 polishes all polishing target parts of the workpiece 100 and finishes the partial polishing step.

As described above, in the present embodiment, in the entire polishing step and the partial polishing step, the top surface of the workpiece 100 is polished by bringing the polishing roll 74 into contact with the workpiece 100 while horizontally moving the chuck table 20 and the polishing roll 74 relative to each other. In other words, the top surface of the workpiece 100 is polished part by part by the polishing roll 74. It is therefore unnecessary to dress the polishing surface of the polishing roll 74 in accordance with the workpiece 100. Because the polishing roll 74 is not worn by the dressing, the frequency of replacement of the polishing roll 74 is reduced. It is therefore possible to suppress cost increase regarding the polishing.

In the present embodiment, even when the thickness of the workpiece 100 is uneven after the entire polishing step, it is possible to partially polish only a thick part of the workpiece 100 in the partial polishing step. It is therefore easy to polish to workpiece 100 to an even thickness.

In this way, the method of polishing the workpiece of the present embodiment makes it possible to produce the workpiece 100 having an even thickness.

In the above-described polishing method, the partial polishing step is performed after the holding step, the entire polishing step, and the measuring step. In this regard, in the present embodiment, the entire polishing step may not be performed, the measuring step may be performed after the holding step, and then the partial polishing step may be performed. Because a thick part of the workpiece 100 can be polished also in this case, it is easy to polish the workpiece 100 to be an even thickness. Furthermore, because the entire polishing step is not performed, time and costs required for the polishing can be reduced.

In addition to the above, in the present embodiment, the entire polishing step and the measuring step may not be performed, and the partial polishing step may be performed after the holding step. In this case, in the partial polishing step after the holding step, a part of the top surface of the workpiece 100 is polished by bringing the polishing roll 74 into contact with a predetermined part of the workpiece 100 while causing the horizontal movement mechanism to move the chuck table 20 and the polishing roll 74 in the horizontal direction relative to each other.

To be more specific, the controller 7 specifies the position of a polishing target part that is a predetermined part (part that should be polished) of the workpiece 100. This polishing target part is, for example, set in the polishing apparatus 1 by an operator. Thereafter, the controller 7 positions the polishing roll 74 above one polishing target part of the workpiece 100 held by the chuck table 20 by controlling the Y-axis movement mechanism 40 and the X-axis movement mechanism 50 to adjust the positions in the horizontal direction of the chuck table 20 and the polishing roll 74.

Then the controller 7 polishes the one polishing target part of the workpiece 100 by starting the supply of the polishing liquid from the polishing liquid nozzle 76 and moving down the polishing roll 74 while rotating the polishing roll 74. In this way, the controller 7 polishes all polishing target parts of the workpiece 100 and finishes the partial polishing step.

According to the configuration above, because only a part requiring polishing (e.g., a thick part) is polished on the workpiece 100, time and costs required for the polishing can be reduced.

In the above-described partial polishing step, the controller 7 positions the polishing roll 74 above one polishing target part of the workpiece 100 by controlling the Y-axis movement mechanism 40 and the X-axis movement mechanism 50 to adjust the positions in the horizontal direction of the chuck table 20 and the polishing roll 74.

In this regard, the controller 7 may utilize the rotating mechanism 26 configured to rotationally drive the chuck table 20, as the horizontal movement mechanism. In this case, in the partial polishing step, the controller 7 positions the polishing roll 74 above a polishing target part of the workpiece 100 by controlling the rotating mechanism 26 and the X-axis movement mechanism 50 (or the Y-axis movement mechanism 40) to adjust the positions in the horizontal direction of the chuck table 20 and the polishing roll 74.

Likewise, the controller 7 may utilize the rotating mechanism 26 as the horizontal movement mechanism also in the entire polishing step of polishing the entire surface of the workpiece 100. In this case, in the entire polishing step, the controller 7 causes the outer side surface of the rotating polishing roll 74 to make contact with a polishing start position on the top surface of the workpiece 100. This polishing start position is, for example, the center of an edge portion on the +Y direction side of the top surface of the workpiece 100 (i.e., the center in the X-axis direction).

Thereafter, the controller 7 causes the Y-axis movement mechanism 40 to linearly move the chuck table 20 in the Y-axis direction (e.g., +Y direction) relative to the polishing roll 74, while causing the rotating mechanism 26 to rotate (rotationally move) the chuck table 20 relative to the polishing roll 74. As a result, the polishing roll 74 makes contact with the entirety of the top surface of the workpiece 100, and polishes the entirety of the top surface of the workpiece 100.

Alternatively, the controller 7 may perform the entire polishing step by using the rotating mechanism 26 and the X-axis movement mechanism 50. In this case, the polishing start position is, for example, the center of an edge portion on the −X direction side of the top surface of the workpiece 100 (i.e., the center in the Y-axis direction). Thereafter, the controller 7 causes the X-axis movement mechanism 50 to linearly move the polishing roll 74 in the X-axis direction (e.g., +X direction) relative to the chuck table 20, while causing the rotating mechanism 26 to rotate the chuck table 20 relative to the polishing roll 74. As a result, the polishing roll 74 makes contact with the entirety of the top surface of the workpiece 100, and polishes the entirety of the top surface of the workpiece 100.

As shown in FIG. 4, the Z-axis moving mechanism 60 may include a tilt adjustment mechanism 66 which is configured to adjust the tilt of the spindle 72 in the polishing mechanism 70. This tilt adjustment mechanism 66 is configured to adjust (change) the tilt of the rotational axis 721 of the polishing roll 74 relative to the workpiece 100 held by the chuck table 20.

In this case, as shown in FIG. 5, the controller 7 is able to bring only a part (e.g., a leading end part) of the outer side surface of the polishing roll 74 into contact with the top surface of the workpiece 100 by adjusting the tilt of the rotational axis 721 of the polishing roll 74 by adjusting the tilt of the spindle 72. This makes it possible to reduce the contact area of the outer side surface (polishing surface) of the polishing roll 74 on the top surface of the workpiece 100.

On this account, for example, the controller 7 is able to partially polish only a narrower part of the top surface of the workpiece 100 in the partial polishing step. Because the top surface of the workpiece 100 can be further precisely polished, it is easy to polish to workpiece 100 to an even thickness.

In the present embodiment, CMP polishing performed such that the workpiece 100 is polished while polishing liquid is supplied to the polishing roll 74. Alternatively, the polishing performed by the polishing apparatus 1 may be dry polishing without the use of polishing liquid. In this case, the polishing mechanism 70 may not have the polishing liquid nozzle 76 and the nozzle shaft 77.

The foregoing detailed description has been presented for the purposes of illustration and description. Many modifications and variations are possible in light of the above teaching. It is not intended to be exhaustive or to limit the subject matter described herein to the precise form disclosed. Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims appended hereto.