Clamping device and substrate holding device

Abstract

The present application provides a clamping device capable of suppressing generation of particles caused by operation of a clamping mechanism, and a substrate holding device having the clamping device. The clamping device has a pin, a base having a pair of supports each having a pair of first opening portions facing each other in an axial direction of the pin and being penetrated by the pin, a lever having an operation portion, a clamping portion, and a support portion provided between the clamping portion and the operation portion, the support portion having a second opening portion penetrated by the pin, a force applying portion having a first locking portion locked to the base, a second locking portion locked to the operation portion, and a coil portion provided between the first locking portion and the second locking portion and penetrated by the pin, the clamping portion being pressed against a substrate by an elastic force of the coil portion acting around the axis of the pin, and one or more first bearings having a first inner ring penetrated by the pin and a first outer ring facing the inner peripheral surface of the coil portion with a space therebetween.

Description

Technical Field

[0001] The present invention relates to a clamping device for holding a substrate and a substrate holding device having the clamping device. Background Art

[0002] In recent years, carrier-circulating continuous sputtering systems have become widely used. These systems are known to have two types: a horizontal transport system, which transports substrates in a horizontal position, and a vertical transport system, which transports substrates in an upright position. Compared to the horizontal transport system, the vertical transport system has the advantage of minimizing the increase in system installation area caused by larger substrates.

[0003] Vertical transport devices use a carrier that transports substrates in a roughly vertical position. This carrier requires a substrate-holding structure that can stably maintain the substrate's position. For example, Patent Document 1 describes a structure that uses multiple clamps positioned around the opening of a carrier to hold the substrate.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: WO2008 / 133139.

[0007] Problems to be solved by the invention

[0008] However, in the structure of Patent Document 1, there is a possibility that particles (metal dust) generated by the mechanical clamping mechanism around the substrate may adhere to the substrate and cause film formation defects. Summary of the Invention

[0009] In view of the above circumstances, an object of the present invention is to provide a clamping device capable of suppressing the generation of particles due to the operation of a clamping mechanism and a substrate holding device including the clamping device.

[0010] Solutions for solving problems

[0011] A clamping device according to one embodiment of the present invention includes:

[0012] pin;

[0013] a base having a pair of brackets, each of the pair of brackets having a pair of first openings facing each other in the axial direction of the pin and penetrated by the pin;

[0014] a lever having an operating portion, a clamping portion, and a supporting portion provided between the clamping portion and the operating portion, the supporting portion having a second opening portion through which the pin is inserted;

[0015] a force-applying portion comprising: a first locking portion locked to the base, a second locking portion locked to the operating portion, and a coil portion provided between the first locking portion and the second locking portion and inserted by the pin, the coil portion being configured to press the clamping portion toward the substrate by elastic force acting around the axis of the pin; and

[0016] The one or more first bearings include a first inner ring through which the pin is inserted, and a first outer ring facing the inner peripheral surface of the coil portion with a space therebetween.

[0017] The first outer ring of the first bearing faces the inner circumferential surface of the coil portion with a space therebetween. Therefore, even if the coil portion is torsionally deformed and reduced in diameter when the clamping is released, the inner circumferential surface of the coil portion is unlikely to come into contact with the first outer ring of the first bearing. Therefore, particles that may be generated due to the contact between the inner circumferential surface of the coil portion and the first outer ring of the first bearing are unlikely to be generated. In addition, even if the inner circumferential surface of the coil portion is in contact with the first outer ring of the first bearing, while the coil portion is circumferentially twisted as it is deformed, the first outer ring of the first bearing is also rotating circumferentially. In this way, since the circumferential twisting of the coil portion and the circumferential rotation of the first outer ring of the first bearing occur substantially simultaneously and with substantially the same displacement, particles that may be generated due to the relative displacement between the inner circumferential surface of the coil portion in contact and the first outer ring of the first bearing are unlikely to be generated.

[0018] Alternatively, the coil portion includes a plurality of winding portions wound in a direction to be twisted by an operating force applied to the operating portion.

[0019] The pitch as the axial interval between the plurality of winding portions is set to a size such that the plurality of adjacent winding portions do not contact each other within the rotation range of the operating portion.

[0020] Because the multiple windings are arranged with spacing between them, the elongation of the coil's axial length resulting from the torsional deformation of the coil is converted into an axial compressive force generated between a pair of brackets. This makes it difficult for adjacent windings to contact each other even if the spacing between adjacent windings decreases (the distance between them becomes closer). In other words, when the coil undergoes torsional deformation, the spacing between adjacent windings provides sufficient play, so the axial movement of the windings is absorbed by the play in the spacing. Therefore, particles (metal dust) generated by contact between adjacent windings are less likely to be generated. Furthermore, because adjacent windings do not contact each other, the force-applying portion is less likely to bend into a "く" shape centered around the central portion. Therefore, when the coil undergoes torsional deformation, the coil remains parallel to the pin, spaced apart from the pin, and the inner circumference of the coil is less likely to contact the first outer ring of the first bearing. Therefore, particles that could be generated by contact between the inner circumference of the coil and the first outer ring of the first bearing are less likely to be generated.

[0021] Optionally, the natural axial length of the force-applying portion is shorter than the distance between the pair of inner surfaces of the pair of brackets in the axial direction.

[0022] The axial length of the force-applying portion in the unloaded state before preload is applied, that is, the natural length, is shorter than the axial distance between a pair of inner surfaces of a pair of brackets. Therefore, even when the coil portion is assembled to the pin in a state in which a preload is applied, sufficient space can be ensured between the coil portion and the pin and between adjacent winding portions.

[0023] Optionally, the clamping device further includes a first collar, the first collar being penetrated by the pin and having an outer peripheral surface facing the inner peripheral surface of the coil portion with a space therebetween, and the first collar contacts the first bearing in the axial direction to position the first bearing.

[0024] The first bearing is positioned by the first collar, so that the first bearing can maintain a state of facing the inner peripheral surface of the coil portion with a space therebetween.

[0025] Optionally, the first collar contacts the first inner ring of the first bearing in the axial direction, but does not contact the first outer ring.

[0026] Since the first collar does not contact the first outer ring of the first bearing, the first collar does not hinder the rotation of the first outer ring, allowing the first outer ring to rotate freely and easily. In addition, particles that may be generated by contact between the first collar and the first outer ring are less likely to be generated.

[0027] Optionally, the clamping device further includes a first washer, the pin penetrates the first washer, the first washer contacts the first bearing and the supporting portion of the rod in the axial direction, and positions the first bearing relative to the rod.

[0028] The first bearing is positioned by the first washer, so that the first bearing can maintain a state of facing the inner peripheral surface of the coil portion with a space therebetween.

[0029] Optionally, the first washer contacts the first inner ring of the first bearing in the axial direction, but does not contact the first outer ring.

[0030] Since the first washer does not contact the first outer ring of the first bearing, it does not hinder the rotation of the first outer ring, allowing the first outer ring to rotate freely. In addition, particles that may be generated by contact between the first washer and the first outer ring are less likely to be generated.

[0031] Optionally, the clamping device further includes a pair of second bearings including a second inner ring through which the pin is inserted, and a second outer ring facing the inner circumferential surfaces of the pair of first openings of the pair of brackets of the base.

[0032] Furthermore, because the main body of the pin is inserted into the first bearing, it does not directly contact the inner surface of the first opening of the bracket. Therefore, when the pin rotates within the first opening of the bracket, particles that might otherwise be generated by contact between the main body of the pin and the inner surface of the first opening of the bracket are less likely to be generated.

[0033] Optionally, the clamping device further includes a pair of second shaft rings, which are penetrated by the pins and contact the first bearing and the second bearing in the axial direction to position the first bearing relative to the base.

[0034] Furthermore, since the main body of the pin is inserted into the second collar, it does not directly contact the inner surface of the first opening of the stent. Therefore, when the pin rotates within the first opening of the stent, particles that might otherwise be generated by the main body of the pin contacting the inner surface of the first opening of the stent are less likely to be generated.

[0035] Optionally, the second collar contacts the first inner ring of the first bearing in the axial direction but does not contact the first outer ring, and contacts the second inner ring of the second bearing in the axial direction but does not contact the second outer ring.

[0036] Since the second collar does not contact the first outer ring of the first bearing, it does not hinder the rotation of the first outer ring, allowing the first outer ring to rotate freely. In addition, particles that may be generated by contact between the first washer and the first outer ring are less likely to be generated.

[0037] Optionally, the clamping device further includes a pair of limiting parts, which are respectively in contact with the second inner rings of the pair of second bearings and not in contact with the second outer rings, and limit the pin from falling off from the pair of first openings.

[0038] Since the restriction portion does not contact the second outer ring, it does not hinder the rotation of the second outer ring, allowing the second outer ring to rotate freely. In addition, the generation of particles that might be generated by the restriction portion contacting the second outer ring is less likely.

[0039] A substrate holding device according to one embodiment of the present invention includes:

[0040] First frame;

[0041] a second frame, a portion of which faces the first frame; and

[0042] a clamping device that holds a substrate between the first frame and the second frame;

[0043] The clamping device has:

[0044] pin;

[0045] a base fixed to the first frame, the base having a pair of brackets, each of the pair of brackets having a pair of first openings facing each other in the axial direction of the pin and penetrated by the pin;

[0046] a lever having an operating portion, a clamping portion, and a supporting portion provided between the clamping portion and the operating portion, the supporting portion having a second opening portion through which the pin is inserted;

[0047] a force-applying portion comprising: a first locking portion locked to the base, a second locking portion locked to the operating portion, and a coil portion provided between the first locking portion and the second locking portion and inserted by the pin, the coil portion being configured to press the clamping portion toward the substrate by elastic force acting around the axis of the pin; and

[0048] The one or more first bearings include a first inner ring through which the pin is inserted, and a first outer ring facing the inner peripheral surface of the coil portion with a space therebetween.

[0049] Effects of the Invention

[0050] According to the present invention, generation of particles due to the operation of the clamping mechanism can be suppressed.

[0051] Furthermore, the effects are not limited to those described here, and any effects described in the present invention may be used. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a perspective view showing the clamp device (excluding the cover) according to the first embodiment of the present invention.

[0053] Figure 2 It is a perspective view showing the clamping device (including the cover).

[0054] Figure 3 It shows that Figure 2 A cross-sectional view of the clamping device (including the cover) in the Z direction, cut along the XY plane passing through the axis of the pin.

[0055] Figure 4 It shows that Figure 1 A cross-sectional view of the clamping device (excluding the cover) in the Z direction downwardly cut along an XY plane passing through the axis of the pin (part of the force-applying portion is not shown).

[0056] Figure 5 It is a plan view showing a double torsion spring serving as a biasing portion.

[0057] Figure 6 Specific examples of dimensional values ​​of the clamping device are shown.

[0058] Figure 7 It is a schematic perspective view schematically showing a substrate holding device.

[0059] Figure 8 It is a side view showing a clamping device included in the substrate holding device.

[0060] Figure 9 This is a cross-sectional view showing the upper side in the Z direction of the clamp device (excluding the cover) according to the second embodiment of the present invention, cut along an XY plane passing through the axis of the pin.

[0061] Figure 10 This is a cross-sectional view showing the upper side in the Z direction of the clamp device (excluding the cover) of the comparative example, cut along an XY plane passing through the axis of the pin.

[0062] Figure 11 It is a plan view showing a double torsion spring serving as a biasing portion.

[0063] Figure 12 Specific examples of dimensional values ​​of the clamping device are shown. DETAILED DESCRIPTION

[0064] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0065] I. First Implementation

[0066] 1. Structure of the clamping device

[0067] Figure 1 It is a perspective view showing the clamp device (excluding the cover) according to the first embodiment of the present invention. Figure 2 It is a perspective view showing the clamping device (including the cover). Figure 3 It shows that Figure 2 A cross-sectional view of the clamping device (including the cover) in the Z direction, cut along the XY plane passing through the axis of the pin. Figure 4 It shows that Figure 1 A cross-sectional view of the clamping device (excluding the cover) in the Z direction downwardly cut along an XY plane passing through the axis of the pin (part of the force-applying portion is not shown).

[0068] The clamping device 1 includes a pin 100, a base 200, a rod 300, a force applying portion 400, four first bearings 500A, 500B, 500C, and 500D, two first collars 600A and 600B, two first washers 700A and 700B, a pair of second bearings 800A and 800B, and a pair of second collars 900A and 900B. The clamping device 1 may further include a cover 1000.

[0069] In the following, without distinguishing between the four first bearings 500A, 500B, 500C, and 500D, the two first shaft rings 600A and 600B, the two first washers 700A and 700B, the pair of second bearings 800A and 800B, and the pair of second shaft rings 900A and 900B, they are respectively referred to as simply the first bearings 500A, 500B, 500C, and 500D, the two first shaft rings 600, the first washers 700, the second bearing 800, and the second shaft ring 900.

[0070] The base 200 includes a bottom plate 205 and a pair of brackets 201 and 202 rising from the bottom plate 205 and facing each other.

[0071] In this specification, the direction in which the pair of brackets 201 and 202 rise from the base plate 205 is referred to as the Z direction, the direction in which the pair of brackets 201 and 202 face each other, i.e., the axial direction of the pin 100, is referred to as the Y direction, and the direction perpendicular to the Z and Y directions is referred to as the X direction. The plane parallel to the surface 206 of the base plate 205 is referred to as the XY plane.

[0072] The bottom plate 205 has two through holes 207 and 208 extending in the Z direction. Bolts 209 and 210 are inserted into the through holes 207 and 208, respectively, thereby fixing the clamping device 1 to a first frame (described later) of the substrate holding device.

[0073] The pair of brackets 201 and 202 have first openings 203 and 204 facing each other in the Y direction, respectively. The pair of first openings 203 and 204 are circular. The inner diameter of the pair of first openings 203 and 204 is slightly larger than the diameter of the main body 101 of the pin 100. The pin 100 is inserted into the pair of first openings 203 and 204.

[0074] The pin 100 has a main body 101 in an elongated cylindrical shape, a head 102 provided at one axial end of the main body 101, and a stepped portion 107 ( Figure 4 The diameter of the step portion 107 as the limiting portion is larger than that of the main body 101 , and the engagement between the step portion 107 and the second inner ring 801A of the second bearing 800A restricts the pin 100 from falling out of the first opening 203 on one side of the base 200 .

[0075] The lever 300 includes an operating portion 301 at one end in the X direction, a clamping portion 302 at the other end in the X direction, and a support portion 304 disposed between the clamping portion 302 and the operating portion 301 and having a second opening 303. The diameter of the second opening 303 is slightly larger than the diameter of the main body 101 of the pin 100. The main body 101 of the pin 100 is inserted into the second opening 303, and the support portion 304 is disposed approximately in the center of the pair of brackets 201 and 202.

[0076] Figure 5 It is a plan view showing a double torsion spring serving as a biasing portion.

[0077] The urging portion 400 is a double torsion spring having a pair of coil portions 401 and 402 wound in opposite directions, arms 403 and 404 serving as a first locking portion, and a center portion 407 serving as a second locking portion.

[0078] Coil portions 401 and 402 each have multiple winding portions 405 and 406 adjacent to each other in the Y direction. The winding portions 405 and 406 are wound in a direction in which the coil portion is twisted by the operating force applied to the operating portion 301, and are arranged with spacing (the spacing between the winding portions 405 and 406 in the Y direction) between them. The main body 101 of the pin 100 is inserted through the coil portions 401 and 402. The inner diameter of the coil portions 401 and 402 is larger than the outer diameter of the first bearing 500 (described later).

[0079] Arms 403 and 404 extend from coil portions 401 and 402, respectively, forming the opposite ends of force-applying portion 400. Arms 403 and 404 are secured to surface 206 of base plate 205 and face inner surfaces 211 and 212 of the pair of brackets 201 and 202, respectively. The Y-direction length of force-applying portion 400, i.e., the Y-direction length from arm 403 to arm 404, is slightly shorter than the Y-direction distance between the inner surfaces 211 and 212 of the pair of brackets 201 and 202. Arms 403 and 404 may or may not contact the inner surfaces 211 and 212 of brackets 201 and 202, respectively.

[0080] The central portion 407 connects the coil portions 401 and 402 in a U-shape. The central portion 407 is locked to the lower surface 305 of the operating portion 301 of the lever 300. When the force-applying portion 400 is assembled to the pin 100 in a state where a preload is applied at a predetermined torsional angle in the winding direction of the winding portions 405 and 406, the arms 403 and 404 are pressed against the surface 206 of the base plate 205, and the central portion 407 is pressed against the lower surface 305 of the operating portion 301. As a result, the central portion 407 of the force-applying portion 400 applies force to the operating portion 301 of the lever 300 upward in the Z direction relative to the base plate 205 of the base 200, generating a predetermined pressing force (holding force) of the clamping portion 302 on the substrate.

[0081] When the operating part 301 of the rod 300 is pressed toward the lower side in the Z direction against the force applied by the force-applying part 400, the rod 300 is rotated relative to the base 200 with the support part 304 as the center, so that the clamping part 302 moves toward the upper side in the Z direction, thereby displacing the clamping part 302 and the operating part 301 relative to the base 200, thereby releasing the pressing force of the clamping part 302 on the substrate.

[0082] As described above, the multiple winding portions 405 and 406 are arranged with spacing (intervals) between them. Specifically, the spacing width is set to a predetermined size so that adjacent winding portions 405 and 406 do not contact each other within the rotation range of the operating portion 301. That is, when the operating portion 301 is pressed, causing the coil portions 401 and 402 to twist in the winding direction, the axial length of the coil portions 401 and 402 extends. After the top ends of the coil portions 401 and 402 abut against the pair of brackets 201 and 202, the extension of the axial length of the coil portions 401 and 402 is converted into a compressive force on the coil portions 401 and 402 between the pair of brackets 201 and 202. Therefore, in this embodiment, the spacing width of the winding portions 405 and 406 is set so that adjacent winding portions do not contact each other due to the compression generated by the coil portions 401 and 402. The spacing width is not particularly limited and can be arbitrarily set based on the dimensions of the various components of the clamping device 1.

[0083] In order to prevent the winding portions of coil units 201 and 202 from contacting each other within the rotational range of operating unit 301, the axial length of the force-applying portion in the unloaded state before applying a preload, i.e., the natural length (free length), can be set to be shorter than the axial distance between the pair of inner surfaces of the pair of brackets. Thus, even when the coil unit is assembled to the pin with a preload applied, sufficient space can be ensured between the coil unit and the pin, and between adjacent winding portions.

[0084] However, the exposed pin 100 is not mounted on the brackets 201 and 202 of the base 200. The pin 100 is inserted into the annular first bearing 500, first collar 600, first washer 700, second bearing 800, and second collar 900. The pin 100 is mounted on the brackets 201 and 202 with the first bearing 500, first collar 600, first washer 700, second bearing 800, and second collar 900 attached. Furthermore, the coils 401 and 402 of the force-applying unit 400 are positioned so as to face the first bearing 500 and first collar 600 mounted on the pin 100. These components are described below.

[0085] The first bearing 500 is a radial bearing without lubricating oil. The first bearing 500 has a first inner ring 501, a first outer ring 502, and rotating bodies (typically balls) between the first inner ring 501 and the first outer ring 502. The inner diameter of the first inner ring 501 is slightly larger than the diameter of the main body portion 101 of the pin 100, and the main body portion 101 of the pin 100 is inserted in the first inner ring 501. The inner diameter of the coil portion 401, 402 is larger than the outer diameter of the first bearing 500. Specifically, the difference between the inner diameter of the coil portion 401, 402 and the outer diameter of the first bearing 500 is larger than the amount of reduction in diameter of the coil portion 401, 402 when the coil portion 401, 402 is twisted and deformed in the winding direction by the operation lever 300. The first outer rings 502A, 502B of the first bearings 500A, 500B face each other with a space from the inner peripheral surface of the coil portion 401 on one side. The first outer rings 502C, 502D of the first bearings 500C, 500D face each other with a space from the inner peripheral surface of the coil portion 402 on the other side.

[0086] The inner diameter of the first collar 600 is slightly larger than the diameter of the main body portion 101 of the pin 100. The outer diameter of the first collar 600 is smaller than the outer diameter of the first bearing 500. The first collar 600 is inserted with the pin 100 to position the first bearing 500. The outer peripheral surface of the first collar 600 is tapered at the junction with the two side surfaces in the Y direction.

[0087] Specifically, the first collar 600A is provided between the two first bearings 500A, 500B, and contacts the first inner rings 501A, 501B of the first bearings 500A, 500B in the Y direction to position the first bearings 500A, 500B. The outer peripheral surface of the first collar 600A faces the inner peripheral surface of the coil portion 401 with a space therebetween. The first collar 600A does not contact the first outer rings 502A, 502B.

[0088] The first collar 600B is provided between the two first bearings 500C, 500D, and contacts the first inner rings 501C, 501D of the first bearings 500C, 500D in the Y direction to position the first bearings 500C, 500D. The outer peripheral surface of the first collar 600B faces the inner peripheral surface of the coil portion 401 with a space therebetween. The first collar 600B does not contact the first outer rings 502C, 502D.

[0089] The inner diameter of the first washer 700 is slightly larger than the diameter of the main body portion 101 of the pin 100. The outer diameter of the first washer 700 is smaller than the outer diameter of the first bearing 500. The first washer 700 is inserted with the pin 100 to position the first bearing 500 with respect to the lever 300.

[0090] Specifically, the first washer 700A contacts the first inner ring 501B of the first bearing 500B and the support portion 304 of the rod 300 in the Y direction to position the first bearing 500B relative to the rod 300 . The first washer 700A does not contact the first outer ring 502B or the inner circumferential surface of the coil portion 401 .

[0091] The first washer 700B contacts the first inner ring 501B of the first bearing 500C and the support portion 304 of the rod 300 in the Y direction to position the first bearing 500C relative to the rod 300. The first washer 700B does not contact the first outer ring 502C or the inner circumferential surface of the coil portion 402.

[0092] The second bearing 800 is a non-lubricated radial bearing. It comprises a second inner ring 801, a second outer ring 802, and a rotating element (typically a ball) positioned between the second inner ring 801 and the second outer ring 802. The inner diameter of the second inner ring 801 is slightly larger than the diameter of the main body 101 of the pin 100, and the main body 101 of the pin 100 is inserted into the second inner ring 801. The second outer ring 802A of the second bearing 800A faces the inner circumference of the first opening 203 of the bracket 201 on one side. The second outer ring 802B of the second bearing 800B faces the inner circumference of the first opening 204 of the bracket 202 on the other side.

[0093] The inner diameter of the second collar 900 is slightly larger than the diameter of the main body 101 of the pin 100. The outer diameter of the second collar 900 is smaller than the outer diameters of the first bearing 500 and the second bearing 800. The pin 100 is inserted into the second collar 900 to position the first bearing 500 and the second bearing 800. The outer circumference of the second collar 900 is tapered at the junction with the two side surfaces in the Y direction.

[0094] Specifically, the second collar 900A is disposed between the first bearing 500A and the second bearing 800A. It contacts the first inner ring 501A of the first bearing 500A and the second inner ring 801A of the second bearing 800A in the Y direction, thereby positioning the first and second bearings 500A, 800A. The outer circumference of the second collar 900A does not contact the inner circumference of the coil portion 401 or the inner circumference of the first opening 203 of the bracket 201. The second collar 900A does not contact the first outer ring 502A of the first bearing 500A or the second outer ring 802A of the second bearing 800A.

[0095] The second collar 900B is disposed between the first bearing 500D and the second bearing 800B. It contacts the first inner ring 501D of the first bearing 500D and the second inner ring 801B of the second bearing 800B in the Y direction, positioning the first bearing 500D and the second bearing 800B. The outer circumference of the second collar 900B does not contact the inner circumference of the coil portion 402 or the inner circumference of the first opening 204 of the bracket 202. The second collar 900B does not contact the first outer ring 502D of the first bearing 500D or the second outer ring 802B of the second bearing 800B.

[0096] A step 107 between the head 102, one end of the pin 100, and the body 101 serves as a restricting portion to prevent the pin 100 from falling out of the first opening 203 of the bracket 201 of the base 200. The step 107 contacts the second inner race 801A of the second bearing 800A but does not contact the second outer race 802A.

[0097] A stopper 104, a second washer 105, and a third washer 106 serve as restrictors and are inserted through the other end 103 of the pin 100. These are arranged in this order from the other end 103 of the pin 100 toward the bracket 202. The stopper 104 and the second washer 105 constrain the other end 103 of the pin 100, preventing the pin 100 from falling out of the first opening 204 of the bracket 202 of the base 200. The third washer 106 contacts the second inner race 801B of the second bearing 800B but does not contact the second outer race 802B.

[0098] 2. Specific examples of size values

[0099] Figure 6 Specific examples of dimensional values ​​of the clamping device are shown.

[0100] For the following dimensions, an error of approximately ±0.1mm is permitted.

[0101] The diameter of the main body 101 of the pin 100 is 6 mm, the diameter of the step portion 107 is 6.8 mm, and the diameter of the head 102 is 9 mm.

[0102] The distance in the Y direction between the pair of inner surfaces 211 and 212 of the pair of brackets 201 and 202 of the base 200 is 42 mm. The inner diameter of the first openings 203 and 204 of the brackets 201 and 202 of the base 200 is 6.5 mm.

[0103] The length of the force-applying portion 400 in the Y direction, that is, the length in the Y direction from the arm 403 to the arm 404 is 40 mm. The spacing (interval) between the multiple winding portions 405 and 406 is 1.4 mm. The spring constant is 0.5668 kgf·mm / deg. The torsion angle is 58.0 deg. The inner diameter of the coil portions 401 and 402 when non-contracted is 12.07 mm, and the inner diameter when contracted is 12.0 mm. That is, the length of the force-applying portion 400 in the Y direction, that is, the length in the Y direction from the arm 403 to the arm 404 (40 mm) is slightly shorter than the distance in the Y direction between the pair of inner surfaces 211 and 212 of the pair of brackets 201 and 202 (42 mm).

[0104] The outer diameter of the first collar 600 is 9 mm. The width of the first collar 600 in the Y direction is 5.8 mm. The inner diameter of the first collar 600 is 6 mm. The outer diameter of the side surface (the flat surface outside the tapered shape) of the first collar 600 is 7.5 mm. The taper angle of the first collar 600 is 45°.

[0105] The outer diameter of the first bearing 500 is 12 mm. The width of the first bearing 500 in the Y direction is 4 mm. That is, the outer diameter of the first collar 600 (9 mm) is smaller than the outer diameter of the first bearing 500 (12 mm).

[0106] The outer diameter of the second bearing 800 is 10 mm, and the width of the second bearing 800 in the Y direction is 3 mm.

[0107] The width of the first gasket 700 in the Y direction is 1 mm.

[0108] The width of the second collar 900 in the Y direction is 4.5 mm.

[0109] The width of the rod 300 in the Y direction is 8 mm.

[0110] The Y-direction spacing (gap) between the inner surfaces 211, 212 of brackets 201, 202 and coil portions 401, 402 is 2.1 mm. The gap between second bearing 800 and second collar 900 is 0.1 mm. The gap between the inner surfaces 211, 212 of brackets 201, 202 and first bearing 500 is 2.1 mm. The gap between first washer 700 and support portion 304 of rod 300 is 0.1 mm.

[0111] 3. Substrate holding device

[0112] Figure 7 It is a schematic perspective view schematically showing a substrate holding device. Figure 8 It is a side view showing a clamping device included in the substrate holding device.

[0113] In a carrier-circulating continuous sputtering system employing a vertical transport system, which transports a substrate 20 in an upright position, the substrate holding device 10 holds the substrate in a substantially vertical position. The substrate 20 is, for example, a mother glass for a liquid crystal display. The dimensions of the substrate 20 are, for example, 2500 mm x 2200 mm (8.5th generation: G8.5) or 3000 mm x 3400 mm (10.5th generation: G10.5).

[0114] The substrate holding device 10 includes a first frame 11, a second frame 12, and a plurality of clamping devices 1. A substrate holding device 10 of size G8.5 includes, for example, 20 clamping devices 1 arranged at predetermined intervals. A substrate holding device 10 of size G10.5 includes, for example, 24 clamping devices 1 arranged at predetermined intervals.

[0115] The first frame 11 and the second frame 12 are rectangular ring-shaped (frame-shaped). The outer diameter of the first frame 11 is larger than the outer diameter of the second frame 12. Parts of the first frame 11 and the second frame 12 face each other in the Z direction. Specifically, the inner area of ​​the first frame 11 and at least the outer area of ​​the second frame 12 face each other in the Z direction in a ring shape. The substrate holding device 10 holds the substrate 20 by clamping the substrate 20 between the first frame 11 and the second frame 12 in the Z direction. Since the first frame 11 and the second frame 12 are formed in a rectangular ring shape, film forming processing can be performed on both surfaces of the substrate 20.

[0116] The base 200 of the clamp 1 is fixed to the inner area of ​​the first frame 11 by bolts 209 and 210. The axial direction (Y direction) of the pin 100 of the clamp 1 is parallel to the main surfaces (XY plane) of the first and second frames 11 and 12.

[0117] When the operating portion 301 of the clamping device 1 is pressed downward in the Z direction, the lever 300 rotates around the support portion 304, causing the clamping portion 302 to move upward in the Z direction, thereby opening the clamping portion 302. When the clamping portion 302 is opened, the substrate 20 is clamped in the Z direction between the first frame 11 and the second frame 12.

[0118] When the downward pressure on the operating portion 301 of the clamping device 1 in the Z direction is released, the lever 300 of the clamping device 1 is biased by the force applying portion 400 and rotates about the support portion 304 relative to the first frame 11 to which the base 200 is fixed. This causes the clamping portion 302 and the operating portion 301 to be displaced relative to the first frame 11 to which the base 200 is fixed. The clamping portion 302 moves downward in the Z direction and contacts the second frame 12. The force applying portion 400 causes the lever 300 to apply force to the first frame 11 to which the base 200 is fixed in order to hold the substrate 20 between the first frame 11 and the second frame 12.

[0119] 4. Action of the clamping device

[0120] The operation of the clamping device 1 when the rod 300 rotates will be described in more detail. When the operating portion 301 of the rod 300 is operated in the -Z direction and rotated in the winding direction of the coil portions 401 and 402, the coil portions 401 and 402 of the force-applying portion 400 twist in the winding direction, the winding diameter shrinks, and the number of windings increases accordingly, thereby deforming in a manner that extends in the Y direction. At this time, since the coil portions 401 and 402 are clamped between the bracket 201 on one side and the support portion 304 of the rod 300, and between the bracket 202 on the other side and the support portion 304 of the rod 300, after the coil portions 401 and 402 come into contact with the brackets 201 and 202 and the support portion 304, a compressive force corresponding to the extension in the Y direction is applied to the coil portions 401 and 402. As described above, the multiple winding portions 405 and 406 are formed with a predetermined spacing (interval) between each other, and the initial Y-direction length of the force-applying portion 400, i.e., the Y-direction length from arm 403 to arm 404, is slightly shorter than the Y-direction distance between the pair of inner surfaces 211 and 212 of the pair of brackets 201 and 202. This is because when the coil portions 401 and 402 are twisted and deformed by pressing the operating portion 301, the amount of reduction in the spacing (interval) between the winding portions 405 and 406 is reduced. Therefore, although the spacing between adjacent winding portions 405 and 406 is shortened (the distance becomes closer), adjacent winding portions 405 and 406 are less likely to contact each other. In other words, even if the coil portions 401 and 402 are twisted and deformed when the clamp is released, the spacing between adjacent winding portions 405 and 406 has sufficient play, so the Y-direction movement of the winding portions 405 and 406 is absorbed by the play in the spacing. Therefore, fine particles (metal dust) generated by contact between adjacent winding portions 405 and 406 are less likely to be generated.

[0121] Furthermore, since the adjacent winding portions 405 and 406 do not contact each other, the force-applying portion 400 is less likely to bend into a "く" shape centered on the central portion 407. Furthermore, as described above, the first outer ring 502 of the first bearing 500 faces the inner circumferential surfaces of the coil portions 401 and 402 with a space therebetween. Specifically, the difference between the inner diameter of the coil portions 401 and 402 and the outer diameter of the first bearing 500 is greater than the amount of diameter reduction of the coil portions 401 and 402 when the operating lever 300 rotates the coil portions 401 and 402 in the winding direction. Therefore, even if the coil portions 401 and 402 are torsionally deformed and reduced in diameter when the clamp is released, the coil portions 401 and 402 are maintained in a parallel state with a space therebetween relative to the pin 100, and the inner circumferential surfaces of the coil portions 401 and 402 are less likely to contact the first outer ring 502 of the first bearing 500. Therefore, particles that might be generated by the inner circumferential surfaces of the coil portions 401 and 402 contacting the first outer ring 502 of the first bearing 500 are less likely to be generated.

[0122] Furthermore, even when the inner circumferential surfaces of coil portions 401 and 402 are in contact with first outer ring 502 of first bearing 500, as coil portions 401 and 402 deform and experience circumferential twisting, first outer ring 502 of first bearing 500 also rotates circumferentially. Thus, because the circumferential twisting of coil portions 401 and 402 and the circumferential rotation of first outer ring 502 of first bearing 500 occur substantially simultaneously and with substantially the same amount of displacement, particles that could potentially be generated due to relative displacement between the inner circumferential surfaces of coil portions 401 and 402 and first outer ring 502 of first bearing 500 are less likely to be generated.

[0123] Furthermore, the first collar 600, first washer 700, and second collar 900 are in contact with the first inner ring 501 of the first bearing 500 and the second inner ring 801 of the second bearing 800, but not with the first outer ring 502 and the second outer ring 802. Therefore, the first collar 600, first washer 700, and second collar 900 do not hinder the rotation of the first outer ring 502 and the second outer ring 802, allowing the first outer ring 502 and the second outer ring 802 to rotate freely. Furthermore, particles that might otherwise be generated by contact between the first collar 600, first washer 700, and second collar 900 and the first outer ring 502 and the second outer ring 802 are less likely to be generated.

[0124] Furthermore, the outer diameters of the first collar 600, the first washer 700, and the second collar 900 are smaller than the outer diameters of the first bearing 500 and the second bearing 800. Therefore, even if the coil portions 401 and 402 are torsionally deformed and reduced in diameter when the clamp is released, the inner circumferential surfaces of the coil portions 401 and 402 are unlikely to come into contact with the outer circumferential surfaces of the first collar 600, the first washer 700, and the second collar 900. Consequently, particles that could potentially be generated by the inner circumferential surfaces of the coil portions 401 and 402 coming into contact with the outer circumferential surfaces of the first collar 600, the first washer 700, and the second collar 900 are unlikely to be generated.

[0125] Furthermore, since the main body 101 of the pin 100 is inserted into the second bearing 800 and the second collar 900, it does not directly contact the inner surfaces of the first openings 203 and 204 of the brackets 201 and 202. Therefore, when the pin 100 rotates within the first openings 203 and 204 of the brackets 201 and 202, particles that might otherwise be generated by contact between the main body 101 of the pin 100 and the inner surfaces of the first openings 203 and 204 of the brackets 201 and 202 are less likely to be generated.

[0126] Furthermore, the step portion 107 of the pin 100 and the third washer 106, which serve as the restricting element, contact the second inner race 801 of the second bearing 800, but not the second outer race 802. Therefore, the step portion 107 of the pin 100 and the third washer 106 do not hinder the rotation of the second outer race 802, allowing the second outer race 802 to rotate freely. Furthermore, the generation of particles that could potentially result from contact between the step portion 107 of the pin 100 and the third washer 106 and the second outer race 802 is less likely.

[0127] II. Second Implementation

[0128] Hereinafter, the same reference numerals are given to the same configurations as those already described, and description thereof will be omitted.

[0129] 1. Structure of the clamping device

[0130] Figure 9 This is a cross-sectional view showing the upper side in the Z direction of the clamp device (excluding the cover) according to the second embodiment of the present invention, cut along an XY plane passing through the axis of the pin.

[0131] The clamping device 2 includes a pin 100, a base 200, a rod 300, a force-applying portion 400, four first bearings 500A, 500B, 500C, and 500D, two first collars 600A and 600B, and a pair of second bearings 800A and 800B. The structures of the base 200, rod 300, force-applying portion 400, first bearings 500, and second bearings 800 are identical to those of the first embodiment. However, the clamping device 2 does not include the first washer 700 and second collar 900 of the first embodiment.

[0132] The pin 100 has a long cylindrical body 101 and a head 102 provided at one axial end of the body 101. The clamping device 2 does not have the stepped portion 107 of the first embodiment. The head 102, which serves as a restricting portion, has a larger diameter than the body 101 and restricts the pin 100 from falling out of the first opening 203 on one side of the base 200.

[0133] Unlike the first embodiment, the first collar 600 does not have a tapered shape. The outer diameter of the first collar 600 is smaller than that of the first bearing 500. As a specific example of the dimensions, the outer diameter of the first bearing 500 is 12 mm, while the outer diameter of the first collar 600 is 11.5 mm. The width of the first collar 600 in the Y direction is 7.8 mm. Other specific examples of the dimensions are the same as those of the first embodiment.

[0134] The first collar 600A is disposed between the two first bearings 500A and 500B. It contacts the first inner races 501A and 501B and the first outer races 502A and 502B of the first bearings 500A and 500B in the Y direction, thereby positioning the first bearings 500A and 500B. The outer circumference of the first collar 600A faces the inner circumference of the coil portion 401, separated by a space.

[0135] The first collar 600B is disposed between the two first bearings 500C and 500D. It contacts the first inner races 501C and 501D and the first outer races 502C and 502D of the first bearings 500C and 500D in the Y direction, thereby positioning the first bearings 500C and 500D. The outer circumference of the first collar 600B faces the inner circumference of the coil portion 401, separated by a space.

[0136] The first inner races 501B and 501C and the first outer races 502B and 502C of the first bearings 500B and 500C are in contact with the support portion 304 of the rod 300 in the Y direction. The first inner races 501A and 501D and the first outer races 502A and 502D of the first bearings 500A and 500D are in contact with the inner surfaces 211 and 212 of the pair of brackets 201 and 202 in the Y direction. The first bearings 500 do not contact the inner circumferential surfaces of the coil portions 401 and 402.

[0137] The head 102 at one end of the pin 100 serves as a restricting portion to restrict the pin 100 from falling out of the first opening 203 of the bracket 201 of the base 200. The head 102 contacts the second inner race 801A and the second outer race 802A of the second bearing 800A.

[0138] A stopper 104 and a second washer 105 are inserted through the other end 103 of the pin 100 as a restricting member. The third washer 106 of the first embodiment is not provided. The stopper 104 and the second washer 105 are arranged in order from the other end 103 of the pin 100 toward the bracket 202. The stopper 104 and the second washer 105 restrain the other end 103 of the pin 100, preventing the pin 100 from falling out of the first opening 204 of the bracket 202 of the base 200. The second washer 105 contacts the second inner race 801B and the second outer race 802B of the second bearing 800B.

[0139] In this embodiment, unlike the first embodiment, the first collar 600 contacts the first inner race 501 and first outer race 502 of the first bearing 500 in the Y direction. The first inner race 501 and first outer race 502 of the first bearing 500 contact the support portion 304 of the rod 300 in the Y direction. The head 102 of the pin 100 contacts the second inner race 801A and second outer race 802A of the second bearing 800A. The second washer 105 contacts the second inner race 801B and second outer race 802B of the second bearing 800B. Therefore, there is a risk of particle generation (metal dust) at these contact points. However, the remaining components have the same structure as the first embodiment, making particle generation less likely.

[0140] III. Comparative Example

[0141] 1. Structure of the clamping device

[0142] Figure 10 This is a cross-sectional view showing the upper side in the Z direction of the clamp device (excluding the cover) of the comparative example, cut along an XY plane passing through the axis of the pin.

[0143] The clamping device 2 includes a pin 100, a base 200, a rod 300, a biasing portion 400, and four first collars 600A, 600B, 600C, and 600D. However, the clamping device 2 does not include the first bearing 500, first washer 700, second bearing 800, and second collar 900 of the first embodiment.

[0144] The pin 100 includes a long cylindrical body 101 and a head 102 provided at one axial end of the body 101. The clamping device 2 does not include the stepped portion 107 of the first embodiment. The head 102, which serves as a restricting portion, has a larger diameter than the body 101 and restricts the pin 100 from falling out of the first opening 203 on one side of the base 200.

[0145] The first collar 600 faces the inner circumferential surfaces of the coil parts 401 and 402 with a space therebetween.

[0146] The first collar 600A contacts the support portion 304 of the rod 300 and the first collar 600B in the Y direction. The first collar 600B contacts the first collar 600A and the inner surface 211 of the bracket 201 in the Y direction. The first collar 600C contacts the support portion 304 of the rod 300 and the first collar 600D in the Y direction. The first collar 600D contacts the first collar 600C and the inner surface 212 of the bracket 202 in the Y direction.

[0147] The head 102 at one end of the pin 100 serves as a restricting portion to restrict the pin 100 from falling out of the first opening 203 of the bracket 201 of the base 200 . The head 102 is in contact with the bracket 201 .

[0148] A stopper 104 and a second washer 105 are inserted through the other end 103 of the pin 100 as a restricting portion. The third washer 106 of the first embodiment is not provided. The stoppers 104 and second washers 105 are arranged in order from the other end 103 of the pin 100 toward the bracket 202. The stoppers 104 and second washers 105 constrain the other end 103 of the pin 100, preventing the pin 100 from falling out of the first opening 204 of the bracket 202 of the base 200. The second washer 105 is in contact with the bracket 202.

[0149] Figure 11 It is a plan view showing a double torsion spring serving as a biasing portion.

[0150] The urging portion 400 is a double torsion spring and includes a pair of coil portions 401 and 402 wound in opposite directions, arms 403 and 404 , and a central portion 407 .

[0151] The coil portions 401 and 402 each have a plurality of winding portions 405 and 406 adjacent to each other in the Y direction. The plurality of winding portions 405 and 406 are arranged with spacing therebetween. This spacing is narrower than that of the first embodiment. Unlike the first embodiment, in the comparative example, the spacing is such that when the rod 300 rotates relative to the base 200 about the support portion 304, thereby displacing the clamping portion 302 and the operating portion 301 relative to the base 200, the plurality of adjacent winding portions 405 and 406 come into contact with each other.

[0152] 2. Specific examples of size values

[0153] Figure 12 Specific examples of dimensional values ​​of the clamping device are shown.

[0154] The diameter of the main body 101 of the pin 100 is 6 mm, and the diameter of the head 102 is 9 mm.

[0155] The distance in the Y direction between the inner surfaces 211 and 212 of the pair of brackets 201 and 202 of the base 200 is 40 mm (narrower than 42 mm in the first and second embodiments). The inner diameter of the first openings 203 and 204 of the brackets 201 and 202 of the base 200 is 6.1 mm.

[0156] The length of the force-applying portion 400 in the Y direction, that is, the length in the Y direction from arm 403 to arm 404, is less than 50.2 mm (longer than 40 mm in the first and second embodiments). The spacing (interval) between the multiple winding portions 405 and 406 is 0.7 mm (narrower than 1.4 mm in the first and second embodiments). The spring constant is 0.5895 kgf·mm / deg (higher than 0.5668 kgf·mm / deg in the first and second embodiments, that is, the rigidity is high). The torsion angle is 55.0 degrees (smaller than 58.0 degrees in the first and second embodiments). The inner diameter of the coil portions 401 and 402 when non-contracted is 11.56 mm (narrower than 12.07 mm in the first and second embodiments), and the inner diameter when contracted is 11.5 mm (narrower than 12.0 mm in the first and second embodiments). The wire diameter of the force-applying portion 400 is 1.8 mm.

[0157] The outer diameter of the first collar 600 is 11.5 mm, and the width of the first collar 600 in the Y direction is 7.8 mm.

[0158] The width of the rod 300 in the Y direction is 8 mm.

[0159] The gap between the inner surfaces 211 , 212 of the brackets 201 , 202 and the first bearing 600 is 0.4 mm.

[0160] 3. Comparative test

[0161] The weight of the individual pins 100, first collars 600, and force-applying members 400, not mounted on the clamping devices 1 and 3, respectively, was measured for the clamping devices 1 of the first embodiment and the clamping devices 3 of the comparative example. Using a testing machine, the rods 300 of the clamping devices 1 of the first embodiment and the clamping devices 3 of the comparative example were opened and closed 100,000 times. After the opening and closing operations, the pins 100, first collars 600, and force-applying members 400 were removed from the clamping devices 1 of the first embodiment and the clamping devices 3 of the comparative example, and their weights were measured. The weight of each pin 100, first collar 600, and force-applying member 400 before and after the opening and closing operations was subtracted from the weight of each pin 100, first collar 600, and force-applying member 400 after the opening and closing operations, resulting in the weight reduction of each component. The total weight reduction of the pin 100, first collar 600, and force-applying member 400 was calculated as the total weight reduction of the clamping devices 1 and 3.

[0162] In the clamp device 1 of the first embodiment, the reduction amount of the pin 100 is 0 mg, the reduction amount of the first collar 600 is 0.3 mg, the reduction amount of the biasing portion 400 is 0.2 mg, and the total reduction amount of the clamp device 1 is 0.5 mg.

[0163] In the clamping device 3 of the comparative example, the reduction amount of the pin 100 is 0.5 mg, the reduction amount of the first collar 600 is 0.2 mg, the reduction amount of the force applying portion 400 is 3.8 mg, and the total reduction amount of the clamping device 3 is 4.5 mg.

[0164] The total reduction amount (0.5 mg) of the clamping device 1 of the first embodiment is 4.0 mg less than the total reduction amount (4.5 mg) of the clamping device 3 of the comparative example, which is reduced to 1 / 9.

[0165] In the present embodiment, the urging portion 400 is a double torsion spring having two coil portions. However, as a modified example, a single torsion spring having one coil portion may be used.

[0166] While the embodiments and modifications of the present technology have been described above, the present technology is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present technology.

[0167] Description of Reference Numerals

[0168] 1, 2, 3: Clamping device

[0169] 10: Substrate holding device

[0170] 100: Sales

[0171] 1000: Cover

[0172] 101: Main body

[0173] 102: Head

[0174] 103: The Other End

[0175] 104: Block

[0176] 105: Second washer

[0177] 106: Third washer

[0178] 107: Stairs

[0179] 11: First Frame

[0180] 12: Second Frame

[0181] 20: Substrate

[0182] 200: Base

[0183] 201, 202: bracket

[0184] 203, 204: First opening

[0185] 205: Base plate

[0186] 206: Surface

[0187] 207, 208: Through holes

[0188] 209, 210: Bolts

[0189] 211, 212: Inner surface

[0190] 300: Rod

[0191] 301: Operation Department

[0192] 302: Clamping part

[0193] 303: Second opening

[0194] 304: Supporting part

[0195] 305: Lower surface

[0196] 400: Force application part

[0197] 401, 402: Coil part

[0198] 403, 404: Arm

[0199] 405: Winding section

[0200] 407: Central Department

[0201] 500, 500A, 500B, 500C, 500D: First bearing

[0202] 501, 501A, 501B, 501C, 501D: First inner circle

[0203] 502, 502A, 502B, 502C, 502D: First outer ring

[0204] 600, 600A, 600B, 600C, 600D: First collar

[0205] 700, 700A, 700B: First gasket

[0206] 800, 800A, 800B: Second bearing

[0207] 801, 801A, 801B: Second inner circle

[0208] 802, 802A, 802B: Second outer ring

[0209] 900, 900A, 900B: Second collar

Claims

1. A clamping device comprising: pin; a base having a pair of brackets, each of the pair of brackets having a pair of first openings facing each other in the axial direction of the pin and penetrated by the pin; a lever having an operating portion, a clamping portion, and a supporting portion provided between the clamping portion and the operating portion, the supporting portion having a second opening portion through which the pin is inserted; a force-applying portion having a first locking portion locked to the base, a second locking portion locked to the operating portion, and a coil portion provided between the first locking portion and the second locking portion and penetrated by the pin, wherein the coil portion presses the clamping portion toward the substrate by an elastic force acting around the axis of the pin; and One or more first bearings each having a first inner ring through which the pin is inserted, and a first outer ring facing the inner peripheral surface of the coil portion with a space therebetween, The coil portion includes a plurality of winding portions wound in a direction twisted by an operating force applied to the operating portion. The pitch as the axial interval between the plurality of winding portions is set to a size such that the plurality of adjacent winding portions do not contact each other within the rotation range of the operating portion.

2. The clamping device according to claim 1, wherein The natural length of the urging portion in the axial direction is shorter than the distance between the pair of inner surfaces of the pair of brackets in the axial direction.

3. The clamping device according to claim 1, wherein: Also features: The pin is inserted through a first collar having an outer peripheral surface facing the inner peripheral surface of the coil portion with a space therebetween. The first collar contacts the first bearing in the axial direction to position the first bearing.

4. The clamping device according to claim 3, wherein: The first collar contacts the first inner ring of the first bearing in the axial direction, but does not contact the first outer ring.

5. The clamping device according to claim 1, wherein Also features: The first washer is inserted through the pin and contacts the first bearing and the support portion of the rod in the axial direction to position the first bearing relative to the rod.

6. The clamping device according to claim 5, wherein: The first washer contacts the first inner ring of the first bearing in the axial direction, but does not contact the first outer ring.

7. The clamping device according to claim 1, wherein: Also features: A pair of second bearings includes a second inner ring through which the pin is inserted, and a second outer ring facing the inner peripheral surfaces of the pair of first openings of the pair of brackets of the base.

8. The clamping device according to claim 7, wherein: Also features: A pair of second collars are inserted by the pin and contact the first bearing and the second bearing in the axial direction to position the first bearing relative to the base.

9. The clamping device according to claim 8, wherein: The second collar contacts the first inner ring of the first bearing in the axial direction but does not contact the first outer ring, and contacts the second inner ring of the second bearing in the axial direction but does not contact the second outer ring.

10. The clamping device according to claim 7, wherein: Also features: A pair of restricting portions are in contact with the second inner races of the pair of second bearings and are not in contact with the second outer races, and restrict the pin from falling out of the pair of first openings.

11. A substrate holding device comprising: First frame; a second frame, a portion of which faces the first frame; and a clamping device that holds a substrate between the first frame and the second frame; The clamping device has: pin; a base fixed to the first frame, the base having a pair of brackets, each of the pair of brackets having a pair of first openings facing each other in the axial direction of the pin and penetrated by the pin; a lever having an operating portion, a clamping portion, and a supporting portion provided between the clamping portion and the operating portion, the supporting portion having a second opening portion through which the pin is inserted; a force-applying portion comprising: a first locking portion locked to the base, a second locking portion locked to the rod, and a coil portion provided between the first locking portion and the second locking portion and inserted by the pin, the coil portion being configured to press the clamping portion toward the substrate by elastic force acting around the axis of the pin; and One or more first bearings each having a first inner ring through which the pin is inserted, and a first outer ring facing the inner peripheral surface of the coil portion with a space therebetween, The coil portion includes a plurality of winding portions wound in a direction twisted by an operating force applied to the operating portion. The pitch as the axial interval between the plurality of winding portions is set to a size such that the plurality of adjacent winding portions do not contact each other within the rotation range of the operating portion.

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