Polishing apparatus and method for polishing workpieces

Abstract

To polish workpieces to a uniform thickness while keeping costs down. [Solution] The upper surface of the workpiece 100 is polished by bringing the polishing roll 74 into contact with the workpiece 100 while moving the chuck table 20 and the polishing roll 74 relatively horizontally. In other words, the upper surface of the workpiece 100 is polished in sections by the polishing roll 74. Therefore, it is unnecessary to dress the polishing surface of the polishing roll 74, which is the polishing tool, to match the workpiece. Consequently, there is no wear on the polishing roll 74 due to such dressing, and the frequency of replacement of the polishing roll 74 can be kept low. This makes it possible to suppress the increase in polishing costs.

Description

【Technical Field】 【0001】 The present invention relates to a polishing apparatus and a method for polishing a workpiece. 【Background Art】 【0002】 As disclosed in Patent Document 1, in a polishing method for polishing a workpiece, a polishing pad having a size that covers the entire surface of the workpiece is rotated to polish the rotating workpiece. In this polishing, since the outer peripheral portion of the workpiece is more difficult to polish than the central portion, a thickness difference is likely to occur in the polished workpiece. Therefore, polishing is performed while relatively moving the workpiece and the polishing pad in the horizontal direction. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2012-106293 【Patent Document 2】 Japanese Patent Application Laid-Open No. 2015-188975 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 Also, in the technique disclosed in Patent Document 2, the polishing surface of the polishing pad is dressed according to the shape of the workpiece. However, when such dressing is performed, the polishing pad is greatly consumed, so the replacement frequency of the polishing pad increases and the cost increases. 【0005】 Therefore, an object of the present invention is to polish a workpiece to a uniform thickness while suppressing costs. 【Means for Solving the Problems】 【0006】 The polishing apparatus of the present invention (this polishing apparatus) comprises a chuck table for holding a workpiece, a polishing mechanism for mounting and rotating a polishing tool for polishing the workpiece, a lifting mechanism for raising and lowering the chuck table and the polishing tool relative to each other in the vertical direction, and a horizontal movement mechanism for moving the chuck table and the polishing tool relative to each other in the horizontal direction, wherein the polishing tool is a cylindrical or columnar polishing roll, and the polishing mechanism comprises a spindle unit that rotates the polishing roll around a rotation axis with the horizontal direction as its longitudinal direction while the polishing roll is mounted, thereby rotating the polishing roll around the rotation axis, and polishing the workpiece with the outer surface of the rotating polishing roll. 【0007】 This polishing apparatus may be equipped with a polishing liquid nozzle for supplying polishing liquid to the polishing roll. 【0008】 This polishing apparatus may include a tilt adjustment mechanism that adjusts the tilt of the rotation axis of the polishing roll relative to the workpiece held on the chuck table. 【0009】 The first workpiece polishing method (first polishing method) in the present invention is a workpiece polishing method using the polishing apparatus, comprising: a holding step of holding the workpiece with the chuck table; and a partial polishing step, after the holding step, of polishing a part of the upper surface of the workpiece by bringing the polishing roll into contact with a predetermined part of the workpiece while moving the chuck table and the polishing roll relative to each other in the horizontal direction by the horizontal movement mechanism. 【0010】 The second workpiece polishing method (second polishing method) in the present invention is a workpiece polishing method using the polishing apparatus, comprising: a holding step of holding the workpiece with the chuck table; and a full-surface polishing step, after the holding step, of polishing the entire upper surface of the workpiece by bringing the polishing roll into contact with the workpiece while moving the chuck table and the polishing roll relative to each other in the horizontal direction by the horizontal movement mechanism. 【0011】 In the second polishing method, the overall polishing step may include polishing the entire upper surface of the workpiece by linearly moving the chuck table relative to the polishing roll in a horizontal direction using the horizontal movement mechanism, while reciprocating the polishing roll in a direction intersecting this direction of movement. 【0012】 The second polishing method may further include a measurement step of measuring the thickness of the entire surface of the workpiece after the overall polishing step, and a partial polishing step of polishing the thicker portion of the workpiece by bringing the polishing roll into contact with a portion of the workpiece that is thicker than a predetermined value, while moving the chuck table and the polishing roll relative to each other in the horizontal direction using the horizontal movement mechanism. [Effects of the Invention] 【0013】 In this invention, the upper surface of a workpiece can be polished by bringing the polishing roll into contact with the workpiece while moving the chuck table and the polishing roll relatively horizontally. In other words, it is possible to polish the upper surface of the workpiece in sections using the polishing roll. Therefore, it is unnecessary to dress the polishing surface (outer surface) of the polishing roll to match the workpiece. Consequently, there is no wear on the polishing roll due to such dressing, and the frequency of replacement of the polishing roll can be kept low. This makes it possible to polish the workpiece to a uniform thickness while reducing polishing costs. [Brief explanation of the drawing] 【0014】 [Figure 1] This is a perspective view showing the configuration of the polishing apparatus. [Figure 2] This is a cross-sectional view showing the holding process. [Figure 3] This is a cross-sectional view showing the full polishing process and the partial polishing process. [Figure 4] This is a cross-sectional view showing a Z-axis movement mechanism equipped with a tilt adjustment mechanism. [Figure 5] This is a cross-sectional view showing other full polishing and partial polishing processes. 【Best Mode for Carrying Out the Invention】 【0015】 As shown in FIG. 1, the polishing apparatus 1 according to this embodiment is an apparatus that polishes a workpiece 100 held on a chuck table 20 with a polishing roll 74. The workpiece 100 has, for example, a circular or rectangular shape, and a protective tape 105 is attached to its lower surface. 【0016】 The polishing apparatus 1 includes a rectangular parallelepiped apparatus base 10, a column 11 extending upward, and a control unit 7 that controls each member of the polishing apparatus 1. 【0017】 An opening 13 is provided on the upper surface side of the apparatus base 10. And a wafer holding mechanism 30 is disposed in the opening 13. 【0018】 The wafer holding mechanism 30 includes a chuck table 20 that holds the workpiece 100, a chuck table base 29 that supports the chuck table 20, a rotation mechanism 26 connected to the proximal end side of the chuck table base 29 via an endless belt 25, a support member 28 that supports the chuck table base 29, and a plurality of support columns 27 that support the support member 28. 【0019】 As shown in FIG. 2, the chuck table 20 has a frame body 23, and a holding portion 21 made of a porous member is provided in a recess provided in the frame body 23. The upper surface of the holding portion 21 serves as a holding surface 22 that sucks and holds the workpiece 100. The holding surface 22 sucks and holds the side of the protective tape 105 of the workpiece 100 by being communicated with a suction source (not shown). 【0020】 The rotation mechanism 26 includes a motor 261 and a drive pulley 262, and rotates the chuck table base 29 by rotating the endless belt 25. Thereby, the chuck table 20 supported by the chuck table base 29 rotates about a table rotation axis passing through the center of the holding surface 22. 【0021】 In addition, the rotation mechanism 26 has an encoder 263. The encoder 263 is rotated when the motor 261 of the rotation mechanism 26 rotates the chuck table 20, and can recognize the rotation amount (rotation speed and rotation angle) of the chuck table 20. 【0022】 On the lower surface of the chuck table 20, a cover plate 39 that moves along the Y-axis direction together with the chuck table 20 is provided. Further, a bellows cover 12 that expands and contracts in the Y-axis direction is connected to the cover plate 39. And below the wafer holding mechanism 30, a Y-axis moving mechanism 40 is disposed. 【0023】 The Y-axis moving mechanism 40 relatively moves the chuck table 20 and the polishing roll 74 of the polishing mechanism 70 in the Y-axis direction (horizontal direction) parallel to the holding surface 22, and is an example of a horizontal moving mechanism. In the present embodiment, the Y-axis moving mechanism 40 is configured to move the wafer holding mechanism 30 including the chuck table 20 in the Y-axis direction with respect to the polishing mechanism 70. 【0024】 The Y-axis moving mechanism 40 includes a pair of Y-axis guide rails 42 parallel to the Y-axis direction, a Y-axis moving table 45 that slides on the Y-axis guide rails 42, a Y-axis ball screw 43 parallel to the Y-axis guide rails 42, a Y-axis motor 44 connected to the Y-axis ball screw 43, a Y-axis encoder 46 for detecting the rotation amount of the Y-axis ball screw 43, and a holding base 41 that holds these components. 【0025】 The Y-axis moving table 45 is slidably installed on the Y-axis guide rails 42. A nut portion (not shown) is fixed to the Y-axis moving table 45. The Y-axis ball screw 43 is screwed into this nut portion. The Y-axis motor 44 is connected to one end of the Y-axis ball screw 43. 【0026】 In the Y-axis movement mechanism 40, the Y-axis motor 44 rotates the Y-axis ball screw 43, causing the Y-axis movement table 45 to move in the Y-axis direction along the Y-axis guide rail 42. The wafer holding mechanism 30 is mounted on the Y-axis movement table 45. Therefore, as the Y-axis movement table 45 moves in the Y-axis direction, the wafer holding mechanism 30, including the chuck table 20, also moves in the Y-axis direction. 【0027】 Furthermore, the Y-axis encoder 46 of the Y-axis movement mechanism 40 is rotated by the Y-axis motor 44 rotating the Y-axis ball screw 43, and can recognize the amount of rotation of the Y-axis ball screw 43 (number of rotations and rotation angle). In this embodiment, the control unit 7 can detect the position of the chuck table 20 in the Y-axis direction based on the amount of rotation of the Y-axis ball screw 43 recognized by the Y-axis encoder 46. 【0028】 Furthermore, a column 11 is erected on the rear (+Y direction side) of the device base 10. On the front of the column 11 are a polishing mechanism 70 for polishing the workpiece 100, a Z-axis moving mechanism 60 for moving the polishing mechanism 70 in the Z-axis direction, and an X-axis moving mechanism 50 for moving the polishing mechanism 70 and the Z-axis moving mechanism 60 in the X-axis direction. 【0029】 The X-axis movement mechanism 50 moves 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) parallel to the holding surface 22, and is an example of a horizontal movement mechanism. In this embodiment, the X-axis movement mechanism 50 is configured to move the polishing mechanism 70, including the polishing roll 74, and the Z-axis movement mechanism 60 in the Z-axis direction relative to the chuck table 20. 【0030】 The X-axis movement mechanism 50 includes a pair of X-axis guide rails 51 parallel to the X-axis direction, an X-axis movement table 53 that slides on the X-axis guide rails 51, an X-axis ball screw 52 parallel to the X-axis guide rails 51, an X-axis motor 54 connected to the X-axis ball screw 52, ​​and an X-axis encoder 55 for detecting the amount of rotation of the X-axis ball screw 52. The Z-axis movement mechanism 60 and the polishing mechanism 70 are attached to the X-axis movement table 53. 【0031】 The X-axis moving table 53 is slidably mounted on the X-axis guide rail 51. A nut (not shown) is fixed to the X-axis moving table 53. An X-axis ball screw 52 is screwed into this nut. The X-axis motor 54 is connected to one end of the X-axis ball screw 52. 【0032】 In the X-axis movement mechanism 50, the X-axis motor 54 rotates the X-axis ball screw 52, ​​causing the X-axis movement table 53 to move in the X-axis direction along the X-axis guide rail 51. As a result, the Z-axis movement mechanism 60 attached to the X-axis movement table 53, and the polishing mechanism 70 supported by the Z-axis movement mechanism 60, also move in the X-axis direction along with the X-axis movement table 53. 【0033】 Furthermore, the X-axis encoder 55 of the X-axis movement mechanism 50 is rotated by the X-axis motor 54 rotating the X-axis ball screw 52, ​​and can recognize the amount of rotation of the X-axis ball screw 52 (number of rotations and rotation angle). In this embodiment, the control unit 7 can detect the position of the polishing roll 74 of the polishing mechanism 70 in the X-axis direction based on the amount of rotation of the X-axis ball screw 52 recognized by the X-axis encoder 55. 【0034】 The Z-axis movement mechanism 60 is an example of a lifting mechanism, and it moves the chuck table 20 and the polishing roll 74 of the polishing mechanism 70 up and down relative to each other in the Z-axis direction (vertical direction) perpendicular to the holding surface 22. In this embodiment, the Z-axis movement mechanism 60 is configured to move the polishing mechanism 70, including the polishing roll 74, up and down in the Z-axis direction relative to the chuck table 20. 【0035】 The Z-axis movement mechanism 60 includes a pair of Z-axis guide rails 61 parallel to the Z-axis direction, a Z-axis movement table 63 that slides on the Z-axis guide rails 61, a Z-axis ball screw 62 parallel to the Z-axis guide rails 61, a Z-axis motor 64 connected to the Z-axis ball screw 62, and a Z-axis encoder 65 for detecting the amount of rotation of the Z-axis ball screw 62. A polishing mechanism 70 is attached to the Z-axis movement table 63. 【0036】 The Z-axis moving table 63 is slidably mounted on the Z-axis guide rail 61. A nut (not shown) is fixed to the Z-axis moving table 63. A Z-axis ball screw 62 is screwed into this nut. The Z-axis motor 64 is connected to one end of the Z-axis ball screw 62. 【0037】 In the Z-axis movement mechanism 60, the Z-axis motor 64 rotates the Z-axis ball screw 62, causing the Z-axis movement table 63 to move in the Z-axis direction along the Z-axis guide rail 61. As a result, the polishing mechanism 70 attached to the Z-axis movement table 63 also moves in the Z-axis direction along with the Z-axis movement table 63. 【0038】 Furthermore, the Z-axis encoder 65 of the Z-axis movement mechanism 60 is rotated by the Z-axis motor 64 rotating the Z-axis ball screw 62, and can recognize the amount of rotation of the Z-axis ball screw 62 (number of rotations and rotation angle). In this embodiment, the control unit 7 can detect the position of the polishing roll 74 of the polishing mechanism 70 in the Z-axis direction based on the amount of rotation of the Z-axis ball screw 62 recognized by the Z-axis encoder 65. 【0039】 The polishing mechanism 70 is equipped with a polishing tool for polishing the workpiece 100 and rotates it, polishing the workpiece 100 held on the chuck table 20. The polishing mechanism 70 comprises a base 71 fixed to the Z-axis moving table 63, a spindle 72 rotatably held on the base 71, a spindle motor 73 for rotationally driving the spindle 72, a polishing roll 74 as a polishing tool attached to the tip of the spindle 72, a polishing liquid nozzle 76 for supplying polishing liquid to the polishing roll 74, and a nozzle shaft 77 supporting the polishing liquid nozzle 76. 【0040】 The spindle 72 extends in the Y-axis direction parallel to the holding surface 22 of the chuck table 20 and is rotatably supported on the base 71. The spindle motor 73 is connected to the base end of the spindle 72. This spindle motor 73 causes the spindle 72 to rotate around a rotation axis 721 (see Figure 2) that passes through the center of the spindle 72 and extends in the Y-axis direction. Thus, the spindle 72, with the polishing roll 74 attached, rotates around a rotation axis 721 whose longitudinal direction is horizontal, thereby forming a spindle unit that rotates the polishing roll 74 around the rotation axis 721. 【0041】 The polishing roll 74 is an example of a polishing tool, and its shape is cylindrical or columnar. The polishing roll 74 is sized to fit within the workpiece 100, and its length in the X-axis and Y-axis directions is smaller than that of the workpiece 100. The polishing roll 74 has material on its outer surface for polishing the workpiece 100 and is mounted on the tip of the spindle 72. The polishing roll 74 is rotated together with the spindle 72 by the spindle motor 73 and contacts the workpiece 100 held in the chuck table 20 with its outer surface to polish the workpiece 100. In this way, the polishing apparatus 1 polishes the workpiece 100 with the outer surface of the rotating polishing roll 74. 【0042】 The nozzle shaft 77 is supported on the base 71 so as to extend in the Y-axis direction along the spindle 72. A polishing fluid nozzle 76 is attached to the tip of the nozzle shaft 77 for supplying polishing fluid to the polishing roll 74. The polishing fluid nozzle 76 is connected to a polishing fluid supply source 78 (see Figure 2) and supplies polishing fluid to the polishing roll 74 when the workpiece 100 is being polished by the polishing roll 74. 【0043】 Furthermore, a non-contact thickness measuring mechanism 80 is provided on the side of the opening 13 in the device base 10. The thickness measuring mechanism 80 includes a non-contact thickness measuring instrument 82 for measuring the thickness of the workpiece 100, an arm portion 83 that supports the non-contact thickness measuring instrument 82 at its tip, and a support member 81 that can support and rotate the arm portion 83. The support member 81 allows the non-contact thickness measuring instrument 82 to rotate and move so as to pass through the center of the holding surface 22 of the chuck table 20. 【0044】 The non-contact thickness measuring instrument 82 measures the thickness of a workpiece 100 held on a chuck table 20 in a non-contact manner. For example, the non-contact thickness measuring instrument 82 irradiates the workpiece 100 from above with measuring light having a wavelength that is transparent to the workpiece 100, receives the top reflected light reflected from the top surface of the workpiece 100 and the bottom reflected light reflected from the bottom surface of the workpiece 100, and measures the thickness of the workpiece 100 by spectral interference. Furthermore, the non-contact thickness measuring instrument 82 is not limited to measuring the thickness of the workpiece 100 by spectral interference as described above. The non-contact thickness measuring instrument 82 may also measure the thickness of the workpiece 100 using ultrasound. Also, the thickness measuring mechanism 80 is not limited to measuring the thickness of the workpiece 100 non-contact as described above. The thickness measuring mechanism 80 may also measure the height of the top surface of the workpiece 100 and the height of the top surface of the chuck table 20 and calculate the thickness of the workpiece 100 from the difference. 【0045】 The control unit 7 includes a CPU that performs calculations according to a control program, and a storage medium such as memory. The control unit 7 controls each of the components of the polishing device 1 as described above, and provides overall control of each component of the polishing device 1. For example, the control unit 7 controls each of the components of the polishing device 1 as described above to perform polishing of the workpiece 100. 【0046】 The polishing method for the workpiece 100 according to this embodiment will be described below. 【0047】 [Holding process] In the polishing method of this embodiment, a holding step is performed first. In this step, the workpiece 100 is held by the chuck table 20. Specifically, as shown in Figure 2, an operator or a transport device (not shown) places the workpiece 100 on the holding surface 22 of the chuck table 20 in the polishing device 1 with the protective tape 105 facing downwards. Then, the control unit 7 of the polishing device 1 connects the holding surface 22 to a suction source, thereby holding the workpiece 100 by suction from the holding surface 22. 【0048】 [Full surface polishing process] After the holding process, a full-surface polishing process is performed. In this process, the chuck table 20 holding the workpiece 100 and the polishing roll 74 are moved relative to each other in the horizontal direction by a horizontal movement mechanism, and the polishing roll 74 is brought into contact with the workpiece 100 to polish the entire upper surface of the workpiece 100. 【0049】 Specifically, the control unit 7 controls the Y-axis movement mechanism 40 and the X-axis movement mechanism 50 to adjust the horizontal position of the chuck table 20 and the polishing roll 74, thereby positioning the polishing roll 74 above the starting position for polishing the upper surface of the workpiece 100 held by the chuck table 20. This starting position for polishing the upper surface of the workpiece 100 is, for example, one end of the edge on the +Y direction side of the upper surface of the workpiece 100 (one end in the X-axis direction). 【0050】 Next, the control unit 7 rotates the polishing roll 74 by rotating the spindle 72 with the spindle motor 73 of the polishing mechanism 70. Then, the control unit 7 lowers the polishing roll 74 with the Z-axis movement mechanism 60 so that the outer surface of the rotating polishing roll 74 comes into contact with the upper surface of the workpiece 100, as shown in Figure 3, and polishes the contact portion. At this time, the control unit 7 starts supplying polishing fluid from the polishing fluid nozzle 76 to the polishing roll 74. 【0051】 Furthermore, the control unit 7 polishes the entire upper surface of the workpiece 100 by linearly moving the chuck table 20 in the horizontal direction relative to the polishing roll 74 using a horizontal movement mechanism, while simultaneously reciprocating the polishing roll in a direction intersecting this movement direction. 【0052】 Specifically, the control unit 7 uses the Y-axis movement mechanism 40 to linearly move the chuck table horizontally in the Y-axis direction (for example, the +Y direction) relative to the polishing roll 74, while the X-axis movement mechanism 50 moves the polishing roll 74 back and forth along the X-axis direction, which is intersecting the Y-axis direction, between one end and the other end of the upper surface of the workpiece 100 in the X-axis direction. As a result, the polishing roll 74 travels in a zigzag pattern while in contact with the upper surface of the workpiece 100, thereby polishing the upper surface of the workpiece 100. 【0053】 The control unit 7 stops the movement of the chuck table 20 and the polishing roll 74 when the entire upper surface of the workpiece 100 has been polished by the polishing roll 74. Furthermore, the control unit 7 stops the supply of polishing fluid from the polishing fluid nozzle 76 and raises the polishing roll 74 using the Z-axis movement mechanism 60 to complete the full-surface polishing process. 【0054】 [Measurement process] After the full-surface polishing process, a measurement process is carried out. In this process, the thickness of the entire surface of the workpiece 100 is measured. 【0055】 Specifically, the control unit 7 controls the Y-axis movement mechanism 40 to position the chuck table 20, which holds the workpiece 100 after the full polishing process, below the thickness measuring mechanism 80 shown in Figure 1. Then, the control unit 7 rotates the chuck table 20 with the rotation mechanism 26, and uses the support member 81 of the thickness measuring mechanism 80 to rotate the non-contact thickness measuring instrument 82 so that it passes through the center of the holding surface 22 of the chuck table 20. In this way, the control unit 7 measures the thickness of the entire surface of the workpiece 100 using the non-contact thickness measuring instrument 82 while changing the relative position of the non-contact thickness measuring instrument 82 with respect to the upper surface of the workpiece 100, and acquires the thickness distribution of the workpiece 100 and stores it as a measurement result. 【0056】 [Partial polishing process] After the measurement process, a partial polishing process is performed. In this process, the control unit 7 moves the chuck table 20 and the polishing roll 74 in the horizontal direction relative to each other using a horizontal movement mechanism, and polishes the thicker parts of the workpiece 100 by bringing the polishing roll 74 into contact with the parts of the workpiece 100 that are thicker than a predetermined value. 【0057】 Specifically, the control unit 7 first identifies the location of a portion of the workpiece 100 that is thicker than a predetermined value (a predetermined thickness value) (a portion that needs polishing) based on the thickness distribution of the workpiece 100 obtained in the measurement process. Then, the control unit 7 controls the Y-axis movement mechanism 40 and the X-axis movement mechanism 50 to adjust the horizontal position of the chuck table 20 and the polishing roll 74, thereby positioning the polishing roll 74 above one of the portions of the workpiece 100 that needs polishing, which is held in the chuck table 20. 【0058】 Subsequently, the control unit 7 starts supplying polishing fluid from the polishing fluid nozzle 76 and rotates and lowers the polishing roll 74 to polish (resharpen) one part of the workpiece 100 that needs polishing to the same thickness as the rest of the workpiece 100. In this way, the control unit 7 finishes the partial polishing process after polishing all the parts of the workpiece 100 that need polishing. 【0059】 As described above, in this embodiment, in the full polishing process and the partial polishing process, the upper surface of the workpiece 100 is polished by bringing the polishing roll 74 into contact with the workpiece 100 while moving the chuck table 20 and the polishing roll 74 relatively horizontally. In other words, the upper surface of the workpiece 100 is polished in sections by the polishing roll 74. Therefore, it is unnecessary to dress the polishing surface of the polishing roll 74 to match the workpiece 100. Consequently, there is no wear on the polishing roll 74 due to such dressing, and the frequency of replacement of the polishing roll 74 can be kept low. Therefore, it is possible to suppress the increase in polishing costs. 【0060】 Furthermore, in this embodiment, even if there are inconsistencies in the thickness of the workpiece 100 after the overall polishing process, the partial polishing process allows for partial polishing of only the thicker parts of the workpiece 100. Therefore, it is easy to polish the workpiece 100 so that its thickness becomes uniform. 【0061】 In the polishing method described above, a partial polishing step is performed after the holding step, the full polishing step, and the measurement step. In this embodiment, however, the full polishing step may be omitted, and the measurement step may be performed after the holding step, followed by the partial polishing step. Even in this case, the thicker parts of the workpiece 100 can be polished, making it possible to polish the workpiece 100 so that its thickness is uniform. Furthermore, since the full polishing step is omitted, the time and cost required for polishing can be reduced. 【0062】 Furthermore, in this embodiment, the full polishing process and the measurement process may be omitted, and the partial polishing process may be performed after the holding process. In this case, in the partial polishing process performed after the holding process, the chuck table 20 and the polishing roll 74 are moved relative to each other in the horizontal direction by a horizontal movement mechanism, and the polishing roll 74 is brought into contact with a predetermined portion of the workpiece 100, thereby polishing a portion of the upper surface of the workpiece 100. 【0063】 Specifically, the control unit 7 identifies the location of a predetermined part (the part to be polished) on the workpiece 100. This part to be polished is set in the polishing device 1, for example, by an operator. Subsequently, the control unit 7 controls the Y-axis movement mechanism 40 and the X-axis movement mechanism 50 to adjust the horizontal position of the chuck table 20 and the polishing roll 74, thereby positioning the polishing roll 74 above one of the parts to be polished on the workpiece 100 held in the chuck table 20. 【0064】 Subsequently, the control unit 7 starts supplying polishing fluid from the polishing fluid nozzle 76 and rotates and lowers the polishing roll 74 to polish one portion of the workpiece 100. In this way, the control unit 7 finishes the partial polishing process after polishing all portions of the workpiece 100. 【0065】 In this configuration, only the parts of the workpiece 100 that require polishing (for example, the thicker parts) are polished, thus reducing the time and cost required for polishing. 【0066】 Furthermore, in the partial polishing process described above, the control unit 7 controls the Y-axis movement mechanism 40 and the X-axis movement mechanism 50 to adjust the horizontal position of the chuck table 20 and the polishing roll 74, thereby positioning the polishing roll 74 above the portion of the workpiece 100 that needs polishing. In this regard, the control unit 7 may use a rotation mechanism 26 that rotates the chuck table 20 as a horizontal movement mechanism. In this case, during the partial polishing process, the control unit 7 adjusts the horizontal position of the chuck table 20 and the polishing roll 74 by controlling, for example, the rotation mechanism 26 and the X-axis movement mechanism 50 (or Y-axis movement mechanism 40), thereby positioning the polishing roll 74 above the part of the workpiece 100 that needs polishing. 【0067】 Similarly, the control unit 7 may also use the rotation mechanism 26 as a horizontal movement mechanism in the full-surface polishing process, which polishes the entire surface of the workpiece 100. In this case, the control unit 7 brings the outer surface of the rotating polishing roll 74 into contact with the polishing start position on the upper surface of the workpiece 100 during the full-surface polishing process. This polishing start position is, for example, the center of the edge on the +Y direction side (center in the X-axis direction) of the upper surface of the workpiece 100. 【0068】 Subsequently, the control unit 7 moves the chuck table 20 linearly in the Y-axis direction (for example, the +Y direction) relative to the polishing roll 74 using the Y-axis movement mechanism 40, while simultaneously rotating (rotating) the chuck table 20 relative to the polishing roll 74 using the rotation mechanism 26. As a result, the polishing roll 74 comes into contact with the entire upper surface of the workpiece 100 and polishes the entire upper surface of the workpiece 100. 【0069】 Furthermore, the control unit 7 may perform the full-surface polishing process using the rotation mechanism 26 and the X-axis movement mechanism 50. In this case, the starting position for polishing is, for example, the center of the -X-direction edge (center in the Y-axis direction) on the upper surface of the workpiece 100. The control unit 7 then moves the polishing roll 74 linearly in the X-axis direction (for example, the +X direction) relative to the chuck table 20 using the X-axis movement mechanism 50, while rotating the chuck table 20 relative to the polishing roll 74 using the rotation mechanism 26. As a result, the polishing roll 74 comes into contact with the entire upper surface of the workpiece 100 and polishes the entire upper surface of the workpiece 100. 【0070】 Furthermore, as shown in Figure 4, the Z-axis movement mechanism 60 may have a tilt adjustment mechanism 66 that adjusts the tilt of the spindle 72 in the polishing mechanism 70. This tilt adjustment mechanism 66 adjusts (changes) the tilt of the rotation axis 721 of the polishing roll 74 relative to the workpiece 100 held on the chuck table 20. 【0071】 In this case, as shown in Figure 5, the control unit 7 adjusts the tilt of the spindle 72, thereby adjusting the tilt of the rotation axis 721 of the polishing roll 74, making it possible to bring only a portion of the outer surface of the polishing roll 74 (for example, the tip) into contact with the upper surface of the workpiece 100. This reduces the contact area of ​​the outer surface (polishing surface) of the polishing roll 74 with the upper surface of the workpiece 100. 【0072】 Therefore, for example, the control unit 7 can partially polish only a narrower portion of the upper surface of the workpiece 100 during the partial polishing process. As a result, the upper surface of the workpiece 100 can be polished more precisely, making it easier to polish the workpiece 100 so that its thickness is uniform. 【0073】 Furthermore, in this embodiment, CMP polishing is performed in which the workpiece 100 is polished while supplying polishing fluid to the polishing roll 74. In this regard, the polishing in the polishing apparatus 1 may be dry polishing without using polishing fluid. In this case, the polishing mechanism 70 does not need to have a polishing fluid nozzle 76 and a nozzle shaft 77. [Explanation of symbols] 【0074】 1: Polishing device, 7: Control unit, 10: Device base, 11: Column, 12: Bellows cover, 13: Opening, 20: Chuck table, 21: Holding part, 22: Holding surface, 23: Frame, 25: Endless belt, 26: Rotating mechanism, 27: Support column, 28: Support member, 29: Chuck table base, 30: Wafer holding mechanism, 39: Cover plate, 40: Y-axis movement mechanism, 41: holding base, 42: Y-axis guide rail, 43: Y-axis ball screw, 44: Y-axis motor, 45: Y-axis moving table, 46: Y-axis encoder, 50: X-axis movement mechanism, 51: X-axis guide rail, 52: X-axis ball screw, 53: X-axis movement table, 54: X-axis motor, 55: X-axis encoder, 60: Z-axis movement mechanism, 61: Z-axis guide rail, 62: Z-axis ball screw, 63: Z-axis moving table, 64: Z-axis motor, 65: Z-axis encoder, 66: Tilt adjustment mechanism, 70: Polishing mechanism, 71: Base, 72: Spindle, 73: Spindle motor, 74: Polishing roll, 76: Polishing fluid nozzle, 77: Nozzle shaft, 78: Polishing fluid supply source, 80: Thickness measuring mechanism, 81: Support member, 82: Non-contact thickness measuring instrument, 83: Arm section, 100: Workpiece, 105: Protective tape, 261: Motor, 262: Drive pulley, 263: Encoder, 721: Rotation axis

Claims

[Claim 1] A polishing apparatus comprising: a chuck table for holding a workpiece; a polishing mechanism for mounting and rotating a polishing tool for polishing the workpiece; a lifting mechanism for raising and lowering the chuck table and the polishing tool relative to each other in the vertical direction; and a horizontal movement mechanism for moving the chuck table and the polishing tool relative to each other in the horizontal direction, The polishing tool is a cylindrical or columnar polishing roll, The polishing mechanism includes a spindle unit that rotates the polishing roll around a rotation axis with the horizontal direction as its longitudinal direction while the polishing roll is mounted on it, thereby rotating the polishing roll around the rotation axis. A polishing device that polishes a workpiece with the outer surface of a rotating polishing roll. [Claim 2] The polishing roll is equipped with a polishing liquid nozzle for supplying polishing liquid, The polishing apparatus according to claim 1. [Claim 3] The device includes a tilt adjustment mechanism that adjusts the tilt of the rotation axis of the polishing roll relative to the workpiece held in the chuck table. The polishing apparatus according to claim 1. [Claim 4] A method for polishing a workpiece using a polishing apparatus described in any one of claims 1 to 3, A holding step in which the workpiece is held by the chuck table, After the holding step, a partial polishing step is performed in which the chuck table and the polishing roll are moved relative to each other in the horizontal direction by the horizontal movement mechanism, and the polishing roll is brought into contact with a predetermined portion of the workpiece, thereby polishing a portion of the upper surface of the workpiece. A method for polishing a workpiece, including [specific details omitted]. [Claim 5] A method for polishing a workpiece using a polishing apparatus described in any one of claims 1 to 3, A holding step in which the workpiece is held by the chuck table, After the holding step, the chuck table and the polishing roll are moved relative to each other in the horizontal direction by the horizontal movement mechanism, and the polishing roll is brought into contact with the workpiece to polish the entire upper surface of the workpiece. A method for polishing a workpiece, including [specific details omitted]. [Claim 6] The overall polishing process includes polishing the entire upper surface of the workpiece by linearly moving the chuck table relative to the polishing roll in a horizontal direction using the horizontal movement mechanism, while reciprocating the polishing roll in a direction intersecting this direction of movement. The method for polishing a workpiece according to claim 5. [Claim 7] After the overall polishing process, a measurement process is performed to measure the thickness of the entire surface of the workpiece. Following the measurement step, a partial polishing step is performed in which the chuck table and the polishing roll are moved relative to each other in the horizontal direction by the horizontal movement mechanism, and the polishing roll is brought into contact with the portion of the workpiece that is thicker than a predetermined value, thereby polishing the thicker portion of the workpiece. The method for polishing a workpiece according to claim 5, further comprising:

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