Grinding device

Abstract

To increase grinding accuracy of a workpiece.SOLUTION: In a grinding device 10, a workpiece is held on an upper surface of a wafer stage 42, and the wafer stage 42 is rotated by a motor 22, thereby rotating the workpiece. In addition, a grinding mechanism grinds the workpiece. Here, a case 24 of the motor 22 supports the wafer stage 42, and a cooling mechanism 36 cools the case 24. Accordingly, machining heat generated at the wafer stage 42, friction heat generated between a bearing stator 38 and a bearing rotor 40, and heat generated in the motor 22 are prevented from being transferred to a bearing base 20 and an angle adjustment mechanism 18. As a result, tilting of the wafer stage 42 can be suppressed, allowing the grinding accuracy of the workpiece to be increased.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a grinding device for grinding a workpiece. [Background technology]

[0002] In the grinding device described in Patent Document 1 below, a chuck table and a shaft (including a support plate) are rotatably supported by a housing and an inclination adjustment mechanism, and the shaft is connected to the rotating shaft of a motor via an endless belt. A workpiece is held on the chuck table, and the motor is operated to rotate the chuck table and the shaft via the endless belt, thereby rotating the workpiece and causing the grinding mechanism to grind the workpiece.

[0003] Here, in this grinding device, if frictional heat is generated between the shaft and the housing as the shaft rotates, and at least one of the chuck table, shaft, housing, and tilt adjustment mechanism thermally expands in the direction of the shaft's rotation axis, the position of the workpiece in the direction of the rotation axis will change, and the accuracy of the workpiece's thickness after grinding will decrease.

[0004] Furthermore, in such a grinding device, by stabilizing the rotation of the chuck table, it is possible to suppress uneven grinding in the circumferential direction of rotation of the workpiece. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2022-184395 Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE INVENTION In consideration of the above, an object of the present invention is to provide a grinding device that can improve the grinding accuracy of a workpiece. [Means for solving the problem]

[0007] A first aspect of the grinding device of the present invention includes a holder that holds and rotates a workpiece, thereby rotating the workpiece; a support that rotatably supports the holder; a grinding mechanism that grinds the workpiece held and rotated by the holder; and a cooling mechanism that cools at least one of the holder and the support.

[0008] A grinding device according to a second aspect of the present invention is the grinding device according to the first aspect of the present invention, further comprising a motor provided with a rotation shaft constituting the holder and operated to rotate the holder.

[0009] A third aspect of the grinding device of the present invention is the grinding device of the first or second aspect of the present invention, wherein an outer wall constitutes the support body, and the cooling mechanism includes a motor that is actuated to rotate the holder and cool the outer wall.

[0010] A fourth aspect of the grinding device of the present invention is a grinding device according to any one of the first to third aspects of the present invention, which includes an axial support portion that is provided on the support body, supports the holder in the direction of the rotation axis, and is cooled by the cooling mechanism.

[0011] A grinding device according to a fifth aspect of the present invention is the grinding device according to any one of the first to fourth aspects of the present invention, further comprising a passage provided in the holder and through which a fluid passes.

[0012] A grinding apparatus of a sixth aspect of the present invention is the grinding apparatus of any one of the first to fifth aspects of the present invention, further comprising a detection device that detects the rotational speed of the holder, and a control device that controls the rotational speed of the holder based on the rotational speed of the holder detected by the detection device.

[0013] A seventh aspect of the grinding device of the present invention includes a holder that holds and rotates a workpiece, causing the workpiece to rotate; a motor that is provided with a rotating shaft that constitutes the holder and is actuated to rotate the holder; and a grinding mechanism that grinds the workpiece that is held and rotated by the holder. [Effects of the Invention]

[0014] In a first aspect of the grinding device of the present invention, a support body rotatably supports a holder, a workpiece is held by the holder, and the workpiece is rotated by rotating the holder, and the grinding mechanism grinds the workpiece held and rotated by the holder.

[0015] Here, a cooling mechanism cools at least one of the holder and the support. Therefore, even if the holder is rotated and frictional heat is generated between the holder and the support, thermal expansion of at least one of the holder and the support in the holder rotation axis direction can be suppressed, and change in the position of the workpiece in the rotation axis direction can be suppressed. This prevents a decrease in the accuracy of the workpiece's thickness after grinding, and improves the grinding accuracy of the workpiece.

[0016] In the grinding device according to the second aspect of the present invention, the motor is operated to rotate the holder.

[0017] Here, the rotating shaft of the motor constitutes the holder, so that the rotation of the holder by the motor can be stabilized.

[0018] In the grinding device according to the third aspect of the present invention, the motor is operated to rotate the holder.

[0019] Here, the outer wall of the motor constitutes the support, and the cooling mechanism cools the outer wall of the motor, so that the support can be easily cooled.

[0020] In the grinding device of the fourth aspect of the present invention, the shaft support portion of the support body supports the holder in the rotation axis direction, and the shaft support portion is cooled by the cooling mechanism, so that the change in the position of the holder in the rotation axis direction can be effectively suppressed, and the change in the position of the workpiece in the rotation axis direction can be effectively suppressed.

[0021] In the grinding device of the fifth aspect of the present invention, a fluid passes through the passage.

[0022] Here, the passage is provided in the holder, so that the passage can be easily arranged.

[0023] In a grinding apparatus according to a sixth aspect of the present invention, a detection device detects the rotation speed of the holder. Furthermore, a control device controls the rotation speed of the holder based on the rotation speed of the holder detected by the detection device. Therefore, the rotation of the holder can be appropriately controlled.

[0024] In the grinding device of the seventh aspect of the present invention, a workpiece is held by a holder, and a motor is operated to rotate the holder, thereby rotating the workpiece. Then, the grinding mechanism grinds the workpiece held and rotated by the holder.

[0025] Here, the rotating shaft of the motor constitutes the holder, which allows for stable rotation of the holder by the motor, suppressing grinding irregularities in the circumferential direction of the workpiece rotation, and improving grinding accuracy of the workpiece. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a side view showing a grinding device according to a first embodiment of the present invention. [Figure 2] 1 is a cross-sectional view showing a holding device of a grinding device according to a first embodiment of the present invention. [Figure 3] FIG. 6 is a cross-sectional view showing a holding device of a grinding device according to a second embodiment of the present invention. [Figure 4] FIG. 10 is a cross-sectional view showing a holding device of a grinding device according to a third embodiment of the present invention. [Figure 5] FIG. 10 is a cross-sectional view showing a holding device of a grinding device according to a fourth embodiment of the present invention. [Figure 6] FIG. 10 is a cross-sectional view showing a holding device of a grinding device according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] [First embodiment] Fig. 1 shows a side view of a grinding apparatus 10 according to a first embodiment of the present invention, and Fig. 2 shows a cross-sectional view of a holding device 12 of the grinding apparatus 10. In the drawings, the upward direction of the grinding apparatus 10 is indicated by an arrow UP.

[0028] As shown in Figures 1 and 2, a base 14 in the shape of a substantially rectangular box is provided at the bottom of the grinding device 10 according to this embodiment as an installation body, and a circular installation hole 14A is formed through the upper wall of the base 14.

[0029] The holding device 12 is installed on the upper wall of the base 14 at the position of the installation hole 14A.

[0030] The holding device 12 is provided with an angle adjustment mechanism 18 that forms the shaft support portion of the support body 16, and the angle adjustment mechanism 18 is fixed to the upper side around the installation hole 14A in the upper wall of the base 14. A circular plate-shaped bearing base 20 that forms the shaft support portion of the support body 16 is supported above the angle adjustment mechanism 18, and the bearing base 20 is arranged coaxially with the installation hole 14A of the base 14.

[0031] A substantially cylindrical motor 22 is mounted on the bearing base 20, and a substantially cylindrical container-like case 24 is provided on the motor 22 as an outer wall constituting the support 16. A cylindrical insertion recess 24A is coaxially formed in the upper part of the case 24, and the upper end of the case 24 forms an expanded diameter portion 24B as a shaft support portion, which protrudes radially outward over the entire circumferential direction. The case 24 is fitted into the bearing base 20 and coaxially inserted into the installation hole 14A of the base 14, and the expanded diameter portion 24B of the case 24 is fixed to the upper side of the bearing base 20. A substantially cylindrical rotating shaft 28 constituting a holder 26 is coaxially mounted within the case 24, and the rotating shaft 28 is rotatably supported by coaxially penetrating the upper and lower walls of the case 24. When the motor 22 is operated, the rotating shaft 28 rotates. A rotary joint 30 is connected to the lower end of the rotating shaft 28.

[0032] A plurality of detectable portions 28A are fixed to the outer periphery of the lower end of rotating shaft 28, and the plurality of detectable portions 28A are arranged at equal intervals in the circumferential direction of rotating shaft 28. A rotation detection sensor 32 serving as a detection device is fixed to the lower surface of case 24, and rotation detection sensor 32 detects detectable portions 28A to detect the rotation speed (rotational angular velocity) of rotating shaft 28. Rotation detection sensor 32 is electrically connected to control device 34, which is also electrically connected to motor 22. Based on the rotation speed of rotating shaft 28 detected by rotation detection sensor 32, control device 34 operates motor 22 to rotate rotating shaft 28 at a constant speed.

[0033] A cooling mechanism 36 is installed in the motor 22. A cylindrical chiller circuit 36A serving as a cooling section is provided within the side wall of the case 24, and the chiller circuit 36A is disposed between the upper end (expanded diameter section 24B) and the lower end of the case 24 (including the side of the bearing base 20). A supply path 36B and a discharge path 36C are connected to the chiller circuit 36A, and the supply path 36B and the discharge path 36C are connected to a cooling circulation device 36D. The cooling circulation device 36D circulates cooling water (fluid) through the supply path 36B, the chiller circuit 36A, and the discharge path 36C while cooling it.

[0034] A cylindrical bearing stator 38 serving as a support member constituting the shaft support portion of the support body 16 is fixed to the upper side of the expanded diameter portion 24B of the case 24, and the bearing stator 38 is arranged coaxially with the case 24. A substantially cylindrical bearing rotor 40 serving as a supported member constituting the holder 26 is arranged coaxially within the bearing stator 38, and the bearing rotor 40 protrudes above and below the bearing stator 38. A bearing recess 40A having a rectangular cross section is formed coaxially in the axially middle portion of the bearing rotor 40 over the entire circumferential direction, and the bearing stator 38 is fitted into the bearing recess 40A, so that the bearing rotor 40 is rotatably supported by the bearing stator 38. The bearing rotor 40 is coaxially inserted into the insertion recess 24A of the case 24 and coaxially coupled to the rotating shaft 28 of the motor 22. The bearing rotor 40 rotates integrally with the rotating shaft 28 and has its interior communicated with the rotating shaft 28.

[0035] A disk-shaped wafer stage 42 (chuck table) serving as a holding unit constituting the holder 26 is coaxially coupled to the upper side of the bearing rotor 40, and the wafer stage 42 rotates integrally with the bearing rotor 40. A disk-shaped porous chuck 42A serving as an adsorption body is coaxially embedded above the wafer stage 42, with the upper surface of the porous chuck 42A exposed above the wafer stage 42. The porous chuck 42A is made of a porous material such as alumina. A workpiece W (see FIG. 1), which is a semiconductor wafer such as a silicon wafer, is transported and placed on the upper side of the porous chuck 42A by a transport device (not shown).

[0036] A suction passage 44 serving as a passage is connected to the underside of the porous chuck 42A, and the suction passage 44 passes through the wafer stage 42 and is piped into the bearing rotor 40 and the rotary shaft 28 of the motor 22. The suction passage 44 passes through the rotary joint 30 and is piped to the outside of the rotary joint 30, and the suction passage 44 is connected to a vacuum source 46 serving as a suction source.

[0037] When the angle adjustment mechanism 18 is activated, the bearing base 20, motor 22, rotary joint 30, bearing stator 38, bearing rotor 40 and wafer stage 42 are tilted, and the upper surface of the porous chuck 42A of the wafer stage 42 is positioned horizontally.

[0038] A moving mechanism 48 is provided on the upper part of the grinding apparatus 10, and the moving mechanism 48 is fixed to the upper side of the base 14. The moving mechanism 48 supports the grinding mechanism 50, and moves the grinding mechanism 50 up and down. A disk-shaped grinding wheel 50A is provided at the lower end of the grinding mechanism 50, and the grinding wheel 50A is arranged horizontally above the wafer stage 42. When the moving mechanism 48 moves the grinding mechanism 50 downward, the grinding wheel 50A is moved onto the workpiece W above the wafer stage 42 (porous chuck 42A). Furthermore, when the grinding mechanism 50 is operated, the grinding wheel 50A is rotated.

[0039] Next, the operation of this embodiment will be described.

[0040] In the grinding apparatus 10 configured as described above, the workpiece W is transported by the transport device and placed coaxially above the porous chuck 42A of the wafer stage 42 in the holding device 12.

[0041] Then, in the holding device 12, the vacuum source 46 is activated and air (fluid) is sucked into the vacuum source 46 through the porous chuck 42A and the suction path 44, generating a negative pressure between the porous chuck 42A and the workpiece W, and the workpiece W is coaxially adsorbed and held on the upper surface of the porous chuck 42A. Furthermore, when the motor 22 is activated, the holder 26 (the rotating shaft 28 of the motor 22, the bearing rotor 40, and the wafer stage 42) is rotated while being supported by the support body 16 (the angle adjustment mechanism 18, the bearing base 20, the case 24 of the motor 22, and the bearing stator 38), and the workpiece W is rotated.

[0042] Next, the moving mechanism 48 moves the grinding mechanism 50 downward, and the grinding mechanism 50 is operated, whereby the grinding wheel 50A of the grinding mechanism 50 is moved onto the workpiece W, the peripheral surface of the grinding wheel 50A is positioned on the central axis of the workpiece W, and the grinding wheel 50A is rotated. As a result, the workpiece W is ground by the grinding wheel 50A.

[0043] When the holder 26 is rotated, frictional heat is generated between the bearing rotor 40 of the holder 26 and the bearing stator 38 of the support body 16 .

[0044] Here, in the cooling mechanism 36, the cooling circulation device 36D circulates cooling water through the chiller circuit 36A inside the side wall of the case 24 of the support 16, so that the cooling water cools the side wall of the case 24 (including the expanded diameter portion 24B), and also cools the angle adjustment mechanism 18, bearing base 20, and bearing stator 38 of the support 16. Therefore, even if the holder 26 is rotated and frictional heat is generated between the bearing rotor 40 and the bearing stator 38, thermal expansion of the angle adjustment mechanism 18, bearing base 20, case 24, and bearing stator 38 in the vertical direction (in the direction of the rotation axis of the holder 26) can be suppressed, and change in the position of the workpiece W in the vertical direction (in the direction of the rotation axis) can be suppressed. This prevents a decrease in the accuracy of the thickness of the workpiece W after grinding, and improves the grinding accuracy of the workpiece W.

[0045] Furthermore, the case 24 of the motor 22 constitutes the support 16, and the cooling mechanism 36 cools the side wall of the case 24. Therefore, the support 16 can be easily cooled.

[0046] Furthermore, the angle adjustment mechanism 18, bearing base 20, enlarged diameter portion 24B of the case 24, and bearing stator 38 support the holder 26 in the vertical direction (direction of the rotation axis), and the angle adjustment mechanism 18, bearing base 20, enlarged diameter portion 24B, and bearing stator 38 are cooled by the cooling mechanism 36, suppressing thermal expansion of the angle adjustment mechanism 18, bearing base 20, enlarged diameter portion 24B, and bearing stator 38. Therefore, changes in the vertical position of the holder 26 can be effectively suppressed, and changes in the vertical position of the workpiece W can be effectively suppressed, effectively improving the grinding accuracy of the workpiece W.

[0047] Moreover, the chiller circuit 36A of the cooling mechanism 36 is disposed on the side wall of the case 24 to the side of the bearing base 20, and is disposed in the heat transfer path from the bearing stator 38 to the bearing base 20. This effectively suppresses thermal expansion of the bearing base 20 in the vertical direction, effectively suppressing changes in the vertical position of the workpiece W, and effectively improving the grinding accuracy of the workpiece W.

[0048] Furthermore, the rotating shaft 28 of the motor 22 constitutes the holder 26. Therefore, unlike when the rotating shaft 28 of the motor 22 is connected to the holder 26 via an endless belt, the transmission of rotational vibration to the holder 26 and the occurrence of rotational irregularities in the holder 26 can be suppressed, the rotation of the holder 26 by the motor 22 can be stabilized, grinding irregularities in the circumferential direction of rotation of the workpiece W can be suppressed, and the grinding accuracy of the workpiece W can be improved.

[0049] Furthermore, the rotation detection sensor 32 detects the rotation speed of the rotating shaft 28 of the motor 22 that constitutes the holder 26, and the control device 34 controls the rotation speed of the holder 26 to be constant based on the rotation speed of the holder 26 detected by the rotation detection sensor 32. Therefore, unlike when the rotation detection sensor 32 detects the rotation speed of the rotating shaft 28 of the motor 22 that is connected to the holder 26 via an endless belt, the rotation of the holder 26 can be appropriately controlled, and the rotation of the workpiece W can be appropriately controlled, thereby effectively suppressing uneven grinding of the workpiece W in the circumferential direction of rotation and effectively improving the grinding accuracy of the workpiece W.

[0050] Furthermore, the suction passage 44 is disposed within the bearing rotor 40 and the rotary shaft 28 of the motor 22. Therefore, the suction passage 44 can be easily disposed.

[0051] [Second embodiment] FIG. 3 shows a cross-sectional view of a holding device 12 of a grinding device 60 according to a second embodiment of the present invention.

[0052] The grinding device 60 according to this embodiment has almost the same configuration as that of the first embodiment, but differs in the following respects.

[0053] As shown in Figure 3, in the grinding device 60 of this embodiment, the expanded diameter portion 24B of the case 24 of the motor 22 is expanded radially outward and downward to form the bearing base 20 of the first embodiment, and the bearing base 20 is not provided separately.

[0054] Here, this embodiment can also achieve the same functions and effects as the first embodiment.

[0055] Furthermore, the expanded diameter portion 24B of the case 24 constitutes the bearing base 20. This simplifies the configuration.

[0056] [Third embodiment] FIG. 4 shows a cross-sectional view of a holding device 12 of a grinding device 70 according to a third embodiment of the present invention.

[0057] The grinding device 70 according to this embodiment has almost the same configuration as that of the first embodiment, but differs in the following respects.

[0058] As shown in FIG. 4, in the grinding device 70 according to this embodiment, the cooling mechanism 36 is installed in the bearing base 20 instead of the motor 22, and the chiller circuit 36A of the cooling mechanism 36 is annular and provided within the bearing base 20.

[0059] Here, in the cooling mechanism 36, the cooling circulation device 36D circulates cooling water through the chiller circuit 36A in the bearing base 20 of the support body 16, so that the cooling water cools the bearing base 20, and also cools the angle adjustment mechanism 18 of the support body 16, the side wall (including the expanded diameter portion 24B) of the case 24, and the bearing stator 38. Therefore, even if the holder 26 is rotated and frictional heat is generated between the bearing rotor 40 and the bearing stator 38, thermal expansion of the angle adjustment mechanism 18, bearing base 20, case 24, and bearing stator 38 in the vertical direction (in the direction of the rotation axis of the holder 26) can be suppressed, and change in the position of the workpiece W in the vertical direction (in the direction of the rotation axis) can be suppressed.

[0060] As a result, this embodiment can also achieve the same functions and effects as the first embodiment.

[0061] [Fourth embodiment] FIG. 5 shows a cross-sectional view of a holding device 12 of a grinding device 80 according to a fourth embodiment of the present invention.

[0062] The grinding device 80 according to this embodiment has almost the same configuration as that of the first embodiment, but differs in the following respects.

[0063] As shown in Figure 5, in the grinding device 80 of this embodiment, the cooling mechanism 36 is installed in the bearing stator 38 instead of the motor 22, and the chiller circuit 36A of the cooling mechanism 36 is provided within the bearing stator 38.

[0064] Here, in the cooling mechanism 36, the cooling circulation device 36D circulates cooling water through the chiller circuit 36A in the bearing stator 38 of the support body 16, so that the cooling water cools the bearing stator 38, and also cools the angle adjustment mechanism 18 of the support body 16, the side wall (including the expanded diameter portion 24B) of the case 24, and the bearing base 20. Therefore, even if the holder 26 is rotated and frictional heat is generated between the bearing rotor 40 and the bearing stator 38, thermal expansion of the angle adjustment mechanism 18, bearing base 20, case 24, and bearing stator 38 in the vertical direction (in the direction of the rotation axis of the holder 26) can be suppressed, and change in the position of the workpiece W in the vertical direction (in the direction of the rotation axis) can be suppressed.

[0065] As a result, this embodiment can also achieve the same functions and effects as the first embodiment.

[0066] In the first to fourth embodiments, the cooling mechanism 36 cools the case 24 of the motor 22, the bearing base 20, or the bearing stator 38. However, it is sufficient if the cooling mechanism 36 cools at least one of the angle adjustment mechanism 18, the case 24 of the motor 22, the bearing base 20, and the bearing stator 38.

[0067] [Fifth embodiment] FIG. 6 shows a cross-sectional view of a holding device 12 of a grinding device 90 according to a fifth embodiment of the present invention.

[0068] The grinding device 90 according to this embodiment has almost the same configuration as that of the first embodiment, but differs in the following respects.

[0069] 6, in a grinding machine 90 according to this embodiment, a cooling mechanism 36 is installed in the bearing rotor 40 instead of the motor 22, and a chiller circuit 36A of the cooling mechanism 36 is provided inside the bearing rotor 40. The chiller circuit 36A has a U-shaped cross section, and the upper and lower ends of the chiller circuit 36A extend radially outward from the bearing rotor 40. A supply path 36B and a discharge path 36C are formed as passages and are piped inside the bearing rotor 40 and the rotary shaft 28 of the motor 22, and the supply path 36B and the discharge path 36C pass through the rotary joint 30, are piped outside the rotary joint 30, and are connected to a cooling circulation device 36D.

[0070] Here, in the cooling mechanism 36, the cooling circulation device 36D circulates cooling water through the chiller circuit 36A in the bearing rotor 40 of the holder 26, so that the cooling water cools the bearing rotor 40, and also cools the wafer stage 42 of the holder 26. Therefore, even if the holder 26 is rotated and frictional heat is generated between the bearing rotor 40 and the bearing stator 38, thermal expansion of the bearing rotor 40 and the wafer stage 42 in the vertical direction (the direction of the rotation axis of the holder 26) can be suppressed, and change in the position of the workpiece W in the vertical direction (the direction of the rotation axis) can be suppressed.

[0071] As a result, this embodiment can also achieve the same functions and effects as the first embodiment.

[0072] Furthermore, the supply passage 36B and the discharge passage 36C are arranged in the bearing rotor 40 and the rotary shaft 28 of the motor 22. Therefore, the supply passage 36B and the discharge passage 36C can be easily arranged.

[0073] In this embodiment, the cooling mechanism 36 cools the bearing rotor 40. However, the cooling mechanism 36 may cool the wafer stage 42, or the cooling mechanism 36 may cool both the wafer stage 42 and the bearing rotor 40.

[0074] In the first to fifth embodiments, the cooling mechanism 36 cools the holder 26 or the support 16. However, the cooling mechanism 36 may cool the holder 26 and the support 16.

[0075] Furthermore, in the first to fifth embodiments, the chiller circuit 36A of the cooling mechanism 36 is cylindrical or annular. However, the chiller circuit 36A of the cooling mechanism 36 may be spiral.

[0076] In addition, in the first to fifth embodiments, the cooling mechanism 36 does not necessarily have to be provided. [Explanation of symbols]

[0077] 10 Grinding equipment 16 Support 18 Angle adjustment mechanism (shaft support part) 20 Bearing base (shaft support part) 22 Motor 24 Case (exterior wall) 24B Expanded diameter part (shaft support part) 26 Holding body 28 Rotation axis 32 Rotation detection sensor (detection device) 34 Control device 36 Cooling mechanism 36B Supply path (passage path) 36C Discharge path (passage path) 38 Bearing stator (shaft support part) 44 Suction path (passage path) 50 Grinding mechanism 60 Grinding equipment 70 Grinding equipment 80 Grinding equipment 90 Grinding equipment double work

Claims

1. a holder that holds and rotates a workpiece, thereby rotating the workpiece; a support body that rotatably supports the holder; a grinding mechanism that grinds the workpiece held by the holder and rotated; a cooling mechanism that cools at least one of the holder and the support; A grinding device comprising:

2. 2. The grinding apparatus according to claim 1, further comprising a motor provided with a rotary shaft constituting said holder and operable to rotate said holder.

3. 2. The grinding device according to claim 1, wherein an outer wall forms the support, and the cooling mechanism includes a motor that is actuated to rotate the holder and cools the outer wall.

4. 2. The grinding device according to claim 1, further comprising a shaft support portion provided on the support body, supporting the holder in the rotation axis direction, and cooled by the cooling mechanism.

5. 2. The grinding device according to claim 1, further comprising a passage provided in said holder for allowing a fluid to pass therethrough.

6. a detection device for detecting the rotation speed of the holder; a control device that controls the rotation speed of the holder based on the rotation speed of the holder detected by the detection device; The grinding device according to claim 1 , comprising:

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