JPH0545885Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to an improvement in a transfer mechanism for horizontally transferring a wafer or the like in and out of a vacuum chamber or the like of a thin film forming apparatus.

B. Prior Art Conventionally, a link transfer mechanism has been used in a vacuum chamber to keep the indoor environment clean, and moreover, a multi-link mechanism having more than three links has been used. That is, as shown in Fig. 4, four links _L1 are pin-coupled in series, their proximal ends are engaged via gear G, and link _L2 is pin-coupled via another _gear G1 at the end. is,
Object A to be transferred was placed at the tip. Then, the gear G is rotated by the first motor _M1 , so that the object A to be moved is transferred drawing a straight line trajectory N, and at the same time, the second motor M2 is rotated by the second motor M2 to move the object _A over a 360 degree range with radius of the trajectory N. had been transferred to.

C. Problems to be solved by the invention This type of link transfer mechanism requires high manufacturing precision in terms of link dimensional accuracy, pin bearing clearance, synchronization gear backlash, etc.
The more links there are, the more these errors accumulate, making it difficult to achieve assembly accuracy, resulting in problems such as insufficient positional accuracy at connection points and dust adhering to these parts scattering into the vacuum chamber. Furthermore, two motors were required, one for extending and retracting the link and one for turning the link.

The object of the present invention is to solve the above-mentioned problems and provide a transfer mechanism that is easy to manufacture, has a high transfer function, and suppresses dust generation.

D. Means for solving the problems In order to achieve the above object, the structure of the present invention is as follows. That is, a fixed first shaft, a first link whose one end is rotatably supported by the first shaft, a second shaft rotatably supported by the other end of the first link, and a first link rotatably supported by the first shaft. a second link, one end of which is fixed to the second shaft and an object to be transferred is placed on the other end; and a second link, which is fixed to the first link and rotatably inserted through the first shaft. A first link rotation part in which a hollow shaft is rotated by a motor, and a sun wheel fixed to the first shaft rotates a planetary wheel fixed to the second shaft as the first link rotates. and an interlocking section that is adapted to move.

E Effect The first link is rotated around the first axis by the operation of the first link rotation part, and the second link is rotated in the opposite direction around the second axis via the interlocking part.
The object placed on the other end is transferred along a straight or arcuate trajectory.

F. Example Hereinafter, an example of the present invention will be described based on the drawings.

1 and 2, the transfer mechanism includes a fixed vertical first shaft 1, a first horizontal link 2 rotatably supported at one end thereof, and a first horizontal link 2 rotatably supported at the other end. It has a vertical second shaft 3 and a horizontal second link 4 having one end fixed to it,
A wafer A, which is an object to be transferred, can be placed on the other end of the second link. The first link 2 is rotatable via a first link rotation part 5, and an interlocking part 6 for imparting rotation to the second link 4 is provided in the hollow body 2a of the first link 2. is provided.

Thus, the first shaft 1 is erected and fixed to a bracket C fixed through the lower wall B of the vacuum chamber, and the first shaft
Support link 2.

The first link rotation part 5 includes a hollow shaft 5a fixed to one end of the first link 2 and rotatably inserted through the first shaft 1, and a passive shaft 5a fitted externally to the lower end of the hollow shaft 5a. It consists of a timing pulley 5b, a stepping motor 5c, a driving timing pulley 5d directly connected thereto, and a timing belt 5e stretched between these two pulleys. A sealing material 12 and an O-ring 13 are attached to the sliding surfaces of the hollow shaft 5a, the shaft 1, and the bracket C to maintain airtightness. As a result, the first link 2
It is said to be rotatable about the axis.

The interlocking unit 6 includes a timing pulley 6a that is fixed to the first shaft 1 and serves as a sun wheel, a timing pulley 6b that is fixed to the second shaft 3 and serves as a planetary wheel, and a timing pulley that is stretched between these two pulleys. belt 6c
It consists of

The second shaft 3 is supported by a thrust bearing 10 and a radial bearing 11 with respect to the first link body 2a.

A concave receiving portion 4a is provided at the other end of the second link 4 to support the wafer.

According to this embodiment, the distance L 1 from the axis M of the first shaft 1 to the axis O of the second shaft 3 in the first link 2, and the distance _L from the axis O to the center P of the wafer A. ₂ are considered the same. Further, the ratio of the diameters (number of teeth) of the sun wheel 6a and the planet wheel 6b is D ₁ :D ₂ =2:
It is 1.

Next, the operating mode will be explained. The motor 5c is activated, and its rotation causes the first link 2 to rotate 180 degrees counterclockwise through the first link rotating portion 5 as shown in the third figure. This rotation causes the second shaft 3 to move along a linear trajectory from O ₀ to O ₈ , and the wafer A moves on a linear trajectory from P ₀ to P ₈ and is accurately transferred to the end point P ₈ . At this point, the wafer A is lowered, and the first and second links 2 and 4 return to their original positions as the motor 5c rotates in the opposite direction.

Here, in the case of D ₁ :D ₂ = 2:1, L ₁ :L ₂ = 1:2, wafer A is transported along a semi-elliptical trajectory from Q ₀ to Q ₈ in FIG. When the rotation angle of the link 2 is 180 degrees, the final position Q ₈ is symmetrical to Q ₀ with respect to the center M of the first axis 1. in this way,
Various transport trajectories can be drawn by changing L ₁ /L ₂ and D ₁ /D ₂ . Further, as the interlocking part 6, a gear including an idler or a chain and chain wheel may be used instead of the above.

Since the interlocking part 6 is housed within the first link, scattering of dust within the vacuum chamber is prevented.

In addition to the horizontal transfer of the above embodiment, by combining a vertical movement mechanism using an air piston cylinder mechanism, it is also possible to receive and deliver wafers.

Further, the wafer receiving portion of the second link may be provided with a vacuum suction nozzle using an ejector.

Of course, the transfer mechanism of the present invention can be applied even in the atmosphere.

G Effect of the invention As described above, the transfer mechanism of the invention includes a fixed first shaft, a first link whose one end is rotatably supported by the first shaft, and a rotatable member at the other end of the first link. a second shaft that is freely supported; a second link that is fixed at one end to the second shaft and on which an object is placed on the other end; and a second link that is fixed to the first link and that a first link rotation part in which a hollow shaft rotatably inserted through the first shaft is rotated by a motor; and a sun wheel fixed to the first shaft and a planet fixed to the second shaft. and an interlocking part configured to rotate the vehicle as the first link rotates. Therefore, since only two links are required, it is easy to achieve manufacturing accuracy, ensure accurate transfer function, generate less dust, and transfer within one plane is possible using only one motor.
Since a stand is sufficient, the transfer mechanism can be provided at a low cost.

[Brief explanation of the drawing]

Figure 1 is a plan view showing one embodiment of the present invention;
The figure is a longitudinal sectional view, FIG. 3 is an explanatory diagram of the operating state, and FIG. 4 is an explanatory diagram of the prior art. A...Wafer, B...Bottom wall of vacuum chamber, 1...
...First axis, 2...First link, 3...Second axis, 4
...Second link, 5...First link rotating part, 5a
...Hollow shaft, 5c...Motor, 6...Interlocking part, 6
a...Sun wheel, 6b...planet wheel.

Claims (1)

[Scope of utility model registration request] a fixed first shaft; a first link rotatably supported at one end by the first shaft; a second shaft rotatably supported by the other end of the first link;
a second link having one end fixed to the shaft and a transferred object placed on the other end; and a hollow shaft fixed to the first link and rotatably inserted through the first shaft. a first link rotation part that is rotated by a motor, and a sun wheel fixed to the first shaft rotates a planetary wheel fixed to the second shaft as the first link rotates. A transfer mechanism characterized by comprising an interlocking section configured as shown in FIG.