JP2000246678A - Thin board conveying robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin board conveying robot capable of sufficiently withstanding for use even in high temperature environment of 100 deg.C or higher. SOLUTION: A first link member 12 is laid between a first large pulley 7 and a first small pulley 11, and the small pulley 11 is rotated on the basis of the displacement of the rotating position of the first large pulley 7 within a first arm 3 caused by the rotation of the first arm 3. A second link member 17 is laid between a second small pulley 13 and a second large pulley 16, and the second large pulley 16 is rotated on the basis of the displacement of the rotating position of the second small pulley 13 within a second arm 4 caused by the rotation of the second arm 4. The first and second link members 12, 17 are respectively formed of stainless wires.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin substrate transfer robot suitable for use in a high temperature environment.

[0002]

2. Description of the Related Art Conventionally, as a robot for transporting a thin substrate such as a semiconductor wafer, a liquid crystal glass substrate, etc., a leading end is a first robot.
A robot main body having a drive shaft connected to a base of the arm, a first arm rotated by the drive shaft, and a first arm disposed inside the base of the first arm, the first arm being rotated by rotation of the first arm; A first large pulley whose rotational position in the arm is displaced, a first support shaft erected inside the distal end of the first arm parallel to the drive shaft, and the distal end of which is located inside the base of the second arm; A first small pulley rotatably disposed at a base of the first support shaft, and a first pulley, which is provided between the first large pulley and the first small pulley, and which is rotated by rotation of the first arm. A first link member for rotating the first small pulley based on a displacement of a rotation position of the one large pulley in the first arm; and a base connected to the first small pulley and rotated by the first small pulley. 2 arm and fixed to the tip of the first support shaft. Second by the rotation of the second arm
A second small pulley whose rotational position in the arm is displaced, a second support shaft erected inside the distal end of the second arm in parallel with the first support shaft, and rotatable about the second support shaft , A second large pulley disposed between the second small pulley and the second large pulley, and a rotation position of the second small pulley in the second arm due to the rotation of the second arm. A second link member for rotating the second large pulley based on the displacement, and a hand connected to the second large pulley and rotated by the second large pulley; 2. Description of the Related Art There is known a thin substrate transfer robot configured to rotate a two-arm and a hand integrally and move the hand up and down, and to bend and extend a first and a second arm to linearly move the hand in a horizontal direction.

[0003]

The conventional transfer robot uses a timing belt made of rubber as the first and second link members. However, recently, plasma C
A transfer robot that can be used in processes that create a high-temperature environment of 100 ° C. or more, such as VD and dry etching, has come to be expected. However, it is difficult to use a conventional transfer robot in such a high-temperature environment. This was not possible due to the rubber properties of the timing belt.

The present invention has been made in view of the above points, and an object of the present invention is to provide a thin substrate transfer robot which can sufficiently withstand use even in a high temperature environment of 100 ° C. or higher. is there.

[0005]

According to the present invention, there is provided a thin substrate transfer robot according to the present invention, comprising: a robot main body having a drive shaft having a distal end connected to a base of a first arm; and a first arm rotated by the drive shaft. A first large pulley disposed inside the base of the first arm, the rotation position of which in the first arm is displaced by the rotation of the first arm; and the drive shaft inside the distal end of the first arm. It stands upright and the tip is the second
A first support shaft located inside the base of the arm, a first small pulley rotatably disposed on the base of the first support shaft, and a first pulley between the first large pulley and the first small pulley. And a first pulley of the first large pulley which is mounted by rotation of the first arm.
A first link member for rotating a first small pulley based on a displacement of a rotational position in the arm; a second arm having a base connected to the first small pulley and being rotated by the first small pulley; A second small pulley which is fixed to a tip of one support shaft and whose rotational position in the second arm is displaced by the rotation of the second arm, and which is parallel to the first support shaft inside the tip of the second arm; A second support shaft erected on the second support shaft, a second large pulley rotatably disposed on the second support shaft, and a second pulley and the second large pulley. Second rotation of the second small pulley by rotation of the second arm
A thin substrate transfer robot comprising: a second link member for rotating a second large pulley based on a displacement of a rotational position in an arm; and a hand connected to the second large pulley and rotated by the second large pulley. , Wherein the first and second link members are made of a heat-resistant wire.

Here, the heat-resistant wire is a stainless wire.

An imaginary straight line between the first large pulley and the first small pulley, the rotation center of which connects the rotation center position of the first large pulley and the rotation center position of the first small pulley. A first tension pulley that is located above and whose center of rotation can be adjusted along the virtual straight line is provided, and a center of rotation between the second large pulley and the second small pulley has a rotation center. A second tension pulley that is located on a virtual straight line connecting the rotation center position of the two large pulleys and the rotation center position of the second small pulley, and whose rotation center position can be adjusted along the virtual straight line. The first link member is provided between the first large pulley and the first small pulley via the first tension pulley, and the second link member is provided between the second large pulley and the second small pulley via the second tension pulley. Small pulley and second large pulley Characterized in that it is installed between the over.

Also, a first bearing disposed between the base of the first arm and the first large pulley, and disposed between the base of the first support shaft and the first small pulley. The second bearing and the third bearing disposed between the second support shaft and the second large pulley are each configured by a ceramic angular bearing in which at least balls are made of a ceramic material.

The first large pulley, the first small pulley, the second small pulley, the second large pulley, the first tension pulley and the second tension pulley are each formed by coating a hard film on an aluminum material. You.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a thin substrate transfer robot according to one embodiment of the present invention.

In FIG. 1, a transfer robot 1 comprises a robot body 2, a first arm 3, a second arm 4, and a hand 5, and the first and second arms 3, 4, and the hand 5
The process chamber 100 is disposed in a vacuum chamber 200 having a high temperature of 100 ° C. or higher by a process such as plasma CVD or dry etching. The transfer robot 1 transfers the semiconductor wafer 300 to be processed from the load lock chamber 400 to the process chamber 100, and transfers the processed semiconductor wafer 300 from the process chamber 100 to the load lock chamber 40.
A transfer robot 1 that carries out a work of transferring the first and second arms 3, 4 and the hand 5 to the robot main body 2 and moving the hand 5 up and down. The two arms 3 and 4 are configured to bend and stretch to move the hand 5 linearly in the horizontal direction.

The robot main body 2 has a drive shaft 6, and a tip 6 a of the drive shaft 6 is connected to a base 3 a of the first arm 3, and the first arm 3 is rotated by the drive shaft 6. A first large pulley 7 is disposed inside the base 3a of the first arm 3. The first large pulley 7 is rotatable with respect to the first arm 3 by a first bearing 8, and the rotation position of the first arm 3 is displaced by the rotation of the first arm 3.

The first arm 3 has a first end 3b inside the first end 3b.
A support shaft 9 is provided upright in parallel with the drive shaft 6. First support shaft 9
Is located inside the base 4 a of the second arm 4. A first small pulley 11 is rotatably provided on a base 9 a of the first support shaft 9 via a second bearing 10. The first large pulley 7 and the first small pulley 11
First arm 3 of first large pulley 7 due to rotation of arm 3
1st pulley 11 based on the displacement of the rotational position in
A first link member 12 for rotating the first link member is provided.

The base 4a of the second arm 4 is connected to the first small pulley 11, and is rotated by the first small pulley 11. A second small pulley 1 is attached to the tip 9 b of the first support shaft 9.
3 is fixed, and the rotation position of the second small pulley 13 in the second arm 4 is displaced by the rotation of the second arm 4.

The second arm 4 has a second end
The support shaft 14 stands upright in parallel with the first support shaft 9. The second large pulley 16 is connected to the second support shaft 14 via a third bearing 15.
Are rotatably arranged. The second large pulley 16 is rotated between the second small pulley 13 and the second large pulley 16 based on the displacement of the rotation position of the second small pulley 13 in the second arm 4 due to the rotation of the second arm 4. Second to move
A link member 17 is provided.

The hand 5 is connected to the second large pulley 16, and the hand 5 is rotated by the second large pulley 16.

Here, the first and second link members 12,
Reference numeral 17 is made of a heat-resistant wire. The material of the heat-resistant wire is not limited as long as it can withstand practical use even in a high temperature environment of 100 ° C. or higher, but a stainless steel wire is particularly preferable. According to the test of the present inventors, it was concluded that the use of a stainless steel wire can sufficiently be put to practical use even in a high-temperature environment of a maximum of 200 ° C.

A first bearing 8 provided between the base 3a of the first arm 3 and the first large pulley 7, and a first pulley 11 provided between the base 9a of the first support shaft 9 and the first small pulley 11. The second established
The bearing 10 and the third bearing 15 disposed between the second support shaft 14 and the second large pulley 16 are each formed of a ceramic angular bearing in which at least balls are made of a ceramic material. Therefore, the transfer robot 1 can be operated with high accuracy and high speed rotation in a high temperature environment.

The first large pulley 7, the first small pulley 11, the second small pulley 13, and the second large pulley 16
Each is formed by coating a hard film on an aluminum material. Examples of the hard film include a carbon hard film (DLC) formed by an ionization vapor deposition method or a high-frequency plasma CVD, and a tuffram film impregnated with Teflon after forming a hard alumite film. First large pulley 7
If particles are formed only from an aluminum material, particles are likely to be generated due to friction with the stainless steel wires 12 and 17, but generation of particles can be prevented by coating the aluminum material with a hard film as described above.

FIG. 2 is a cross-sectional view of a main part of a thin substrate transfer robot according to another embodiment, FIG. 3 is a plan view showing an internal configuration of a first arm, and FIG. 4 is an internal configuration of a second arm. FIG. 5 is an explanatory view for explaining the wiring method of the first and second link members, and FIG. 6 is an explanatory view for explaining the operation of the tension pulley.

The transfer robot 1 shown in FIG. 2 is a transfer robot 1 used in a high-temperature environment of 100 ° C. or higher, like the transfer robot 1 shown in FIG. 1, and its basic configuration is shown in FIG. The configuration is substantially the same as that of the transfer robot 1, except that first and second tension pulleys 18 and 19 are provided.
There is a difference in that the tension of the second link members 12, 17 is adjusted.

2 to 4, the robot main body 2 has a drive shaft 6. The distal end 6a of the drive shaft 6 passes through the central hole 7a of the first large pulley 7 disposed inside the base 3a of the first arm 3, and is fixed to the support member 20 above the central hole 7a. The support member 20 is fixed to the bottom plate 3c of the first arm 3 and extends upward from the bottom plate 3c.
a and a distal end 20b extending from the upper end of the base 20a in a direction approaching the drive shaft 6. Drive shaft 6
Is fixed to the distal end portion 20b of the support member 20 using the wedge 21. As described above, the distal end 6a of the drive shaft 6 is connected to the base 3a of the first arm 3,
The first arm 3 is rotatable by a drive shaft 6.

The first large pulley 7 is rotatable with respect to the first arm 3 by a first bearing 8, and the first large pulley 7 is moved inside the first arm 3 by the rotation of the first arm 3. The rotational position is displaced.

The first arm 3 has a first end 3b inside the first end 3b.
A support shaft 9 is provided upright in parallel with the drive shaft 6. First support shaft 9
Is located inside the base 4 a of the second arm 4. A first small pulley 11 is rotatably provided on a base 9 a of the first support shaft 9 via a second bearing 10.

A first tension pulley 18 is arranged between the first large pulley 7 and the first small pulley 11. The first tension pulley 18 has a pivot 18
a is a virtual straight line V connecting the rotation center position 7b of the first large pulley 7 and the rotation center position 11a of the first small pulley 11.
It is rotatably held by the support block 22 so as to be located at L1.

A first arm 3 is provided between the first large pulley 7, the first small pulley 11, and the first tension pulley 18.
A first link member 12 (FIG. 3) for rotating the first small pulley 11 based on the displacement of the rotation position of the first large pulley 7 in the first arm 3 due to the rotation of the first large pulley 7 is provided.

The first link member 12 is made of a heat-resistant wire, for example, a stainless wire. As shown in FIG. 5, the stainless wire includes two upper and lower stainless wires 12A and 12B.

The stainless wires 12A and 12B are installed between the first large pulley 7, the first small pulley 11 and the first tension pulley 18 as follows. First, the upper stainless steel wire 12A has a steel ball 12a connected to one end thereof fixed in the upper cutout groove 11b of the first small pulley 11, and the first stainless steel pulley 11 is rotated about one and a half clockwise when viewed from above. The first large pulley 7 is also wound clockwise approximately half a turn, the first tension pulley 18 is further wound clockwise approximately half a turn, and the first large pulley 7 is further wound clockwise about one and a half turns. The other end of the steel ball 12b is fixed in the upper cutout groove 7c of the first large pulley 7. on the other hand,
The lower stainless steel wire 12B is formed by connecting the steel ball 12c connected to one end thereof to the lower cutout groove 11c of the first small pulley 11.
And wound around the first small pulley 11 counterclockwise as viewed from above by about one and a half turn, further wound around the first large pulley 7 in the same counterclockwise direction by about a half turn, and further counterclockwise wound around the first tension pulley 18. The steel ball 12d is wound approximately half a turn clockwise and further wound half a turn counterclockwise around the first large pulley 7, and the steel ball 12d at the other end is fixed in the lower cutout groove 7d of the first large pulley 7. In this way, two stainless steel wires 12A,
The first small pulley 11 can be rotated with good balance by the rotation of the first large pulley 7 by erection of the 12B.

The support block 22 has a substrate 22a, and a plurality of long holes 3d are formed in the bottom plate 3c of the first arm 3. The longitudinal direction of each elongated hole 3d matches the longitudinal direction of the first arm 3, and the mounting bolt 23 is inserted into each elongated hole 3d. These mounting bolts 23 are attached to the substrate 22a.
Are fixed to the first arm 3 to fix the rotation center position 18a of the first tension pulley 18. When these mounting bolts 23 are loosened, the mounting bolts 23 can be moved in the longitudinal direction in the elongated hole 3d,
Therefore, the support block 22 can move in the longitudinal direction. That is, the rotation center position 18a of the first tension pulley 18 can be adjusted along the virtual straight line VL1.

The drive shaft side member 22b of the support block 22 is provided with a screw groove 22c along the longitudinal direction of the first arm 3, and the tip end 24a of the tension adjusting bolt 24 is screwed into the screw groove 22c. ing. The adjustment bolt 24 is always in a state where its head 24b is in contact with the base 20a of the support member 20. By adjusting the amount of screwing into the screw groove 22c, the adjustment bolt 24 is moved from the base 20a of the support member 20 to the support block 22. Distance to the drive shaft side member 22b,
In other words, the rotation center position 18a of the first tension pulley 18 can be adjusted.

Here, as shown in FIG. 6, when the first tension pulley 18 is displaced from the state shown by the solid line in the figure to the state shown by the two-dot chain line in the figure, the entire length of the first link member 12 is reduced by the first tension pulley 18. Can be increased by about twice the moving distance D of the rotation center 18a. On the other hand, in order to increase the total length of the first link member 12 by the same length as the above by using the conventional tension roll 25 shown by the broken line in FIG. It is necessary to set the distance larger than the moving distance D of the tension pulley 18.
Therefore, by using the first tension pulley 18 as described above, the amount of change in the tension of the first link member 12 with respect to the moving distance D of the first tension pulley 18 can be increased.

A second small pulley 13 is fixed to the tip 9b of the first support shaft 9. The rotation position of the second small pulley 13 in the second arm 4 is displaced by the rotation of the second arm 4.

The second arm 4 has a second end 4b
The support shaft 14 stands upright in parallel with the first support shaft 9. The second large pulley 16 is connected to the second support shaft 14 via a third bearing 15.
Are rotatably arranged.

The second small pulley 13 and the second large pulley 16
A second tension pulley 19 is disposed between the first and second pulleys. As shown in FIG. 4, the rotation center 19a of the second tension pulley 19 has a rotation center position 13a of the second small pulley 13 and a rotation center position 16a of the second large pulley 16.
and is rotatably held by the support block 26 so as to be located on a virtual straight line VL2 connecting the line a and the line a.

The second small pulley 13 and the second large pulley 16
A second link for rotating the second large pulley 16 based on the displacement of the rotation position of the second small pulley 13 in the second arm 4 due to the rotation of the second arm 4 between the second tension pulley 19 and the second tension pulley 19. A member 17 (FIG. 4) is provided.

The second link member 17, like the first link member 12, is made of a heat-resistant wire, for example, a stainless wire, and is composed of two upper and lower stainless wires.

Each stainless wire is laid between the second small pulley 13, the second large pulley 16, and the second tension pulley 19 in the same manner as the stainless wires 12A and 12B of the first link member 12 described above. By rotating the second small pulley 13, the second large pulley 16 can be rotated with good balance.

The support block 26 has a substrate 26a, on which a plurality of elongated holes 26b (FIG. 4) are formed. The longitudinal direction of each elongated hole 26b matches the longitudinal direction of the second arm 4, and each elongated hole 26b has a mounting screw 27.
(FIG. 4) is inserted from above and screwed into the bottom plate 4c of the second arm 4. These mounting screws 27
a to the second arm 4 and the second tension pulley 19
For fixing the rotation center position 19a. When these mounting screws 27 are loosened, the mounting screws 27
Can be moved in the longitudinal direction in the elongated hole 26b, so that the support block 26 can be moved in the longitudinal direction. That is, the rotation center position 1 of the second tension pulley 19
9a can be adjusted along the virtual straight line VL2.

The second small pulley side member 26 c of the support block 26 has a thread groove 2 along the longitudinal direction of the second arm 4.
6d is cut, and the tip 28a of the tension adjusting bolt 28 is screwed into the screw groove 26d. The adjusting bolt 28 is inserted into a through hole 29 a of a bolt supporting member 29 fixed to the bottom surface of the second arm 4, and the lower surface of the head 28 b is always the surface of the bolt supporting member 29 on the side of the second small pulley 13. 29b in contact with thread groove 2
6b by adjusting the screwing amount into the bolt supporting member 2
9 to the second pulley-side member 26c of the support block 26
Distance, in other words, the second tension pulley 19
Can be adjusted.

By using such a second tension pulley 19, the amount of change in the tension of the second link member 17 with respect to the moving distance of the second tension pulley 19 is increased, similarly to the first tension pulley 18 described above. Will be able to do that.

The hand 5 is connected to the second large pulley 16, and the hand 5 is rotated by the second large pulley 16.

Here, a first bearing 8 and a first support shaft 9 provided between the base 3a of the first arm 3 and the first large pulley 7 are provided.
The second bearing 10 and the second support shaft 14 and the second large pulley 16 are disposed between the base 9a of the second pulley 11 and the first small pulley 11.
The third bearings 15 disposed between the first and second bearings are each formed of a ceramic angular bearing in which at least balls are made of a ceramic material.

The first large pulley 7, the first small pulley 11, the first tension pulley 18, the second small pulley 1
3. Second large pulley 16 and second tension pulley 1
9 are each formed by coating a hard film on an aluminum material. Examples of the hard film include a carbon hard film (DLC) formed by an ionization vapor deposition method or a high-frequency plasma CVD, and a tuffram film impregnated with Teflon after forming a hard alumite film.

As described above, the first and second link members 12, 17 are made of a heat-resistant wire, preferably a stainless steel wire. Therefore, according to the transfer robot 1 of the present embodiment, it can be sufficiently put into practical use even in a high-temperature environment of a maximum of 200 ° C.

The first bearing 8, the second bearing 10, and the third bearing
Since each of the bearings 15 is constituted by a ceramic angular bearing in which at least balls are made of a ceramic material, the transfer robot 1 can be operated with high accuracy and high speed rotation in a high temperature environment.

Also, the first large pulley 7, the first small pulley 11, the first tension pulley 18, the second small pulley 1
3. Second large pulley 16 and second tension pulley 1
9 is formed by coating an aluminum material with a hard film, thereby preventing generation of particles.

[0048]

According to the thin substrate transfer robot of the present invention, the first and second link members are each made of a heat-resistant wire, preferably a stainless steel wire.
Even under a high temperature environment of 0 ° C., it can be practically used.

Further, between the first large pulley and the first small pulley, the rotation center is on an imaginary straight line connecting the rotation center position of the first large pulley and the rotation center position of the first small pulley. A first tension pulley which is located and whose rotation center position is adjustable along the virtual straight line;
The rotation center is between the large pulley and the second small pulley.
A second tension pulley is provided on a virtual straight line connecting the rotation center position of the large pulley and the rotation center position of the second small pulley, and the rotation center position is adjustable along the virtual straight line. The first link member is provided between the first large pulley and the first small pulley via the first tension pulley, and the second link member is provided between the second small pulley and the second small pulley via the second tension pulley. By being constructed between the large pulley and the large pulley, the amount of change in the tension of the first and second link members with respect to the moving distance of the first and second tension pulleys can be increased.

A first bearing disposed between the base of the first arm and the first large pulley; a second bearing disposed between the base of the first support shaft and the first small pulley; Further, the third bearing disposed between the second support shaft and the second large pulley is constituted by a ceramic angular bearing in which at least balls are made of a ceramic material, so that the transfer robot can be operated in a high temperature environment. Can be operated with high precision and high-speed rotation.

Also, a first large pulley, a first small pulley,
By forming the second small pulley, the second large pulley, the first tension pulley, and the second tension pulley by coating a hard film on an aluminum material, it is possible to prevent generation of particles.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a thin substrate transfer robot according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a thin substrate transfer robot according to another embodiment.

FIG. 3 is a plan view showing an internal configuration of a first arm.

FIG. 4 is a plan view showing an internal configuration of a second arm.

FIG. 5 is an explanatory diagram for explaining a wiring method of first and second link members.

FIG. 6 is an explanatory diagram for explaining an operation of a tension pulley.

[Explanation of symbols]

 Reference Signs List 1 thin substrate transfer robot 2 robot body 3 first arm 3a base 3b tip 4 second arm 4a base 4b tip 5 hand 6 drive shaft 6a tip 7 first large pulley 7b rotation center position 8 first bearing 9 First support shaft 9a Base 9b Tip 10 Second bearing 11 First small pulley 11a Rotation center position 12 First link member 13 Second small pulley 13a Rotation center position 14 Second support shaft 15 Third support shaft 16 Large pulley 16a Rotation center position 17 Second link member 18 First tension pulley 18a Rotation center position 19 Second tension pulley 19a Rotation center position VL1, VL2 Virtual straight line

Claims (5)

[Claims] 1. A robot main body having a drive shaft having a distal end connected to a base of a first arm; a first arm rotated by the drive shaft; and a robot disposed inside the base of the first arm. The rotation position of the first arm is displaced by the rotation of the first arm.
A large pulley, a first support shaft erected inside the distal end of the first arm in parallel with the drive shaft, and a distal end positioned inside the base of the second arm; A first small pulley movably disposed; a first small pulley erected between the first large pulley and the first small pulley; rotation of the first large pulley in the first arm by rotation of the first arm; A first link member for rotating the first small pulley based on the displacement of the position, a second arm having a base connected to the first small pulley, and being rotated by the first small pulley; A second position, which is fixed to the distal end portion and whose rotational position in the second arm is displaced by the rotation of the second arm;
A small pulley; a second support shaft erected inside the distal end of the second arm in parallel with the first support shaft; and a second large pulley rotatably disposed on the second support shaft. The second large pulley is provided between the second small pulley and the second large pulley, and rotates the second large pulley based on displacement of a rotation position of the second small pulley in the second arm due to rotation of the second arm. And a hand connected to the second large pulley and rotated by the second large pulley, wherein the first and second link members are each made of a heat-resistant wire. A thin substrate transfer robot characterized by being constituted. 2. The thin substrate transfer robot according to claim 1, wherein the heat-resistant wire is a stainless wire. 3. The rotation control device according to claim 1, wherein a rotation center is between the first large pulley and the first small pulley.
A first tension pulley is provided on a virtual straight line connecting the rotation center position of the large pulley and the rotation center position of the first small pulley, and the rotation center position is adjustable along the virtual straight line. The rotation center is located on a virtual straight line connecting the rotation center position of the second large pulley and the rotation center position of the second small pulley between the second large pulley and the second small pulley. And a second tension pulley whose rotation center position is adjustable along the virtual straight line, wherein the first link member includes a first large pulley and a first small pulley via the first tension pulley. Wherein the second link member is provided between the second small pulley and the second large pulley via the second tension pulley. 4. The first bearing according to claim 3, wherein the first bearing is disposed between the base of the first arm and the first large pulley.
A second bearing disposed between the base of the first support shaft and the first small pulley, and a third bearing disposed between the second support shaft and the second large pulley. A thin substrate transfer robot, wherein at least each of the balls is constituted by a ceramic angular bearing made of a ceramic material. 5. The hard disk according to claim 4, wherein the first large pulley, the first small pulley, the second small pulley, the second large pulley, the first tension pulley, and the second tension pulley each include a hard film formed of an aluminum material. A thin substrate transfer robot formed by coating.