JPH02100887A - Transfer device - Google Patents

Abstract

PURPOSE:To miniaturize the device whole body by providing a work placing post driven by rotation by a parallel linking mechanism at one end part of the arm made by storing the parallel linking mechanism inside a sealed case and constituting so as to rotate and drive the arm as well as driving the parallel linking mechanism by a driving mechanism. CONSTITUTION:By a 1st geared motor 14 in a driving mechanism 11 1st arm 23 and 2nd arm, 42 are rotated in the mutual reverse direction the wafer carrier(work) 51 placed on a placing post 47 is linearly moved in an arrow mark A direction and a work 51 is positioned on the transfer passage of the other part from on the transfer passage of one part. Then, a 2nd geared motor 39 is driven, a 1st rotary shaft 18 is rotated, a 2nd main link plate 31 in a parallel link mechanism is reciprocated along the longitudinal direction and a 2nd link plate 46c is eccentrically rotated. The placing post 47 is rotated by this eccentric rotation and the position of the work 51 is controlled.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a transfer device suitable for transferring a workpiece such as a wafer carrier for storing wafers in a clean room for semiconductor manufacturing, etc. Regarding.

(Prior art) In order to move a wafer carrier containing wafers to the next process in a semiconductor manufacturing process, a transfer device is installed in a clean room to grasp the wafer carrier placed on one transfer path (or station). The transfer to the other conveyance path is automated. That is, in operations where dust is particularly averse, such as semiconductor manufacturing processes, wafer carriers can be transferred without any intervention by the operator.

By the way, conventional transfer apparatuses have generally been constructed as shown in FIG. That is, 1 in the figure is the first mounting table,
2 is a second mounting table. A wafer carrier 3 (hereinafter referred to as a workpiece 3) is placed on the first mounting table 1. A pedestal 4 is provided above the first and second mounting tables 1.2 and intersects therewith, and a guide rail 5 is provided on this pedestal 4. This guide rail 5 has a moving head 6
is supported movably in the direction of arrow a, and this moving head 6
A gripping mechanism 7 is supported so as to be movable up and down.

When the workpiece 3 is to be transferred, the workpiece 3 on the first mounting table 1 is gripped by the gripping mechanism 7. Next, this gripping mechanism 7 is raised and moved above the second mounting table 2 by the moving head 6. And work 3
The gripping mechanism 7 that grips the workpiece 3 is lowered, and the workpiece 3 is moved to the second
Transfer it to the mounting table 2.

In this way, the workpiece 3 can be transferred by moving the gripping mechanism 7 that grips the workpiece 3 in the horizontal and vertical directions.

However, the transfer device that transfers the workpiece 3 by moving the gripping mechanism 7 in the horizontal and vertical directions not only increases the size of the entire device, but also increases the size of the workpiece 3 by moving the gripping mechanism 7 in the horizontal and vertical directions. Since the drive mechanism of the transfer device moves, there is also the problem that dust falls onto the mounting table 1.2 and the workpiece 3.

Furthermore, when the mounting table 1.2 is a magnetically levitated vehicle, for example, when transferring the workpiece 3 held by the gripping mechanism 7, the magnetically levitated vehicle is suppressed downward by the workpiece 3, and the workpiece 3 is It will receive a load greater than its weight. Therefore, the magnetic levitation vehicle consumes a large amount of levitation energy, which adversely affects its levitation state. Furthermore, if the structure is such that the workpiece 3 is held in place, if the workpiece 3 is not positioned accurately, the gripping mechanism 7
In some cases, it may not be possible to securely hold the object.

(Problems to be Solved by the Invention) As described above, the conventional transfer device has a structure in which the workpiece is held between the gripping mechanisms and the gripping mechanisms are moved in the horizontal and vertical directions, which increases the overall size of the device. When transferring a workpiece to a magnetic levitation vehicle, there have been problems such as adversely affecting the levitation state of the workpiece, and furthermore, it may not be possible to hold the workpiece unless it is accurately positioned. .

This invention was made based on the above-mentioned circumstances, and its purpose is to provide a transfer device that can remove the various drawbacks mentioned above by making it possible to transfer a workpiece without pinching it. It is about providing.

[Structure of the Invention] (Means and Effects for Solving the Problems) In order to solve the above problems, the present invention provides an arm in which a parallel link mechanism is housed in a sealed case, and an arm that is rotatable at one end of the arm. a workpiece mounting table which is provided in and rotationally driven by the parallel link mechanism; a drive shaft which is connected to the other end of the arm and drives the parallel link mechanism; and a drive mechanism that rotates and drives the end portion as a fulcrum. By rotating the arm while driving the parallel link mechanism, the workpiece placed on the mounting table can be transferred in a predetermined posture.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

The transfer device, not shown in FIG. 1, includes a drive mechanism 11. As shown in FIG. This drive mechanism 11 includes a container-shaped main body 12. A first boss portion 12a is provided vertically on the inner surface of the upper surface of the main body 12, and a bottomed cylindrical support 13 is attached to the first boss portion 12a.
It is rotatably supported by a bearing 13a. A first geared motor 14 is provided at an eccentric position at the bottom of the support 13, with its rotating shaft 15 protruding into the support 13. A pair of first gears 16 of different diameters constituting a gear train are fitted onto the rotating shaft 15, and a pair of second gears 17 are also meshed with the first gears 16.

This second gear 17 is connected to a hollow first drive shaft 18 which will be described later.
It is fitted on one end of the . In addition, this first drive shaft 1
A third gear 19 is fitted into one end of the gear 8 , and this third gear 19 meshes with the fourth gear 21 . This fourth gear 21 meshes with an internal gear 22 formed on the inner circumferential surface of the support 13, and also engages with a first arm 2 which will be described later.
It is rotatably connected by a pin 25 to a coupling ring 24a fitted to a second boss part 24 as a second drive shaft protruding from one end of the drive shaft. Therefore, when the first geared motor 14 operates, the first drive shaft 18 is rotationally driven through the first and second gears, and the boss portion is driven through the third and fourth gears. 24 is rotated, and the first arm 23 is interlocked with this rotation.

The second boss portion 24 is rotatably supported within the first boss portion 2a on the upper surface of the main body 12 by a second bearing 26. The first arm 23 from which the second boss portion 24 is protruded forms a first sealed case 28 that is sealed by a lid 27 . Inside this first sealed case 28, a first main link plate 29 and a second main link plate 31, which constitute a first parallel link mechanism and a second parallel link mechanism, respectively, are vertically parallel to each other. They are housed spaced apart. These main link plates 29.31 have first to third mounting holes 29a to 29C131a to 3 at one end, the other end, and a midway part, respectively.
1C is drilled. Each mounting hole 29a to 29c, 3
1a to 31c have disc-shaped first to third link plates 32a to 32C% 33a to 3, respectively.
3c is rotatably provided via a bearing.

A first support shaft 34 passes through the eccentric position of the first link plate (32a, 33a) provided at one end of each main link plate (29, 31).
The upper and lower ends of 4 are supported by the sealing case 28 of the first arm 23 and the lid 27. Further, a connecting shaft 35 is protruded from an eccentric position on the upper surface of the second link plate 32b provided at the other end of the first main link plate 29.
This connecting shaft 35 is connected to the second main link plate 31
It is rotatably inserted into a hollow shaft 36 protruding from the upper surface side of a second link plate 33b provided at the other end. The upper end portions of the connecting shaft 35 and the hollow shaft 36 protrude outside from the lid 27 of the first arm 23.

The hollow first drive shaft 18 is vertically disposed at an eccentric position on the lower surface of the third link plate 32c provided in the middle of the first main link plate 31. This first drive shaft 18 has a third link plate 33 provided in the middle of the second main link plate 31.
A third drive shaft 37, the upper end of which is fitted in c, is inserted through the third drive shaft 37. The lower end of the third drive shaft 37 protrudes from the bottom of the support 13 toward the lower surface, and the protruding end is connected to the rotating shaft 41 of the second geared motor 39 by a joint 38. Therefore, if the third drive shaft 37 is driven by the second geared motor 39 to eccentrically rotate the third link plate 33c in the middle of the second main link plate 31, the second main link plate 33c is rotated eccentrically. The link plate 33b at the other end can be eccentrically rotated via the link plate 31.

A midway portion of a second arm 42 is rotatably connected to the other end of the first arm 23 . That is, this second arm 42 is similar to the first arm 23 described above, as is the lid body 43.
The third main link plate 45 constituting a third parallel link mechanism is housed inside the second sealed case 44. Attachment holes 45a to 45c are formed in one end, the other end, and the middle of the third main link plate 45, respectively, and the first to third link plates 46 are formed in each of the attachment holes 45a to 45c.
a to 46c are rotatably provided via bearings.

A second support shaft 47 passes through an eccentric position of the first link plate 46a provided at one end of the third main link plate 45, and the upper and lower ends of the second support shaft 47 are connected to the second arm 4.
It is supported by 2. Further, the upper end portion of the hollow shaft 36 protruding from the second link plate 32b of the second main link plate 31 is non-rotatably fitted into the eccentric position of the third link plate 46c in the middle. . The upper end of the connecting shaft 35 inserted into the hollow shaft 36 is connected to the lid 4.
3 is fixed with screws. Further, a shaft portion 48 protruding from the lower surface of the mounting table 47 is fitted into an eccentric position of the second link plate 46b provided at the other end of the third main link plate 45. This shaft portion 48 is rotatably supported by the lid 43 of the second arm 42 and the second sealed case 44 by a bearing 49. Therefore, the g4 mounting stand 47 is rotationally driven by the third main link plate 45 via the second link plate 46b. A wafer carrier 51 as a workpiece is placed on the mounting table 47. An engagement flange 52 extends outward from the upper end of the wafer carrier 51 .

Note that the first to fourth gears 16.17.1 are driven by the first geared motor 14 at a speed ratio of 1:2, so that the first arm 23 and the second arm 42 are driven by the first geared motor 14 at a speed ratio of 1:2.
The number of teeth is set at 8.19.21. Further, the main body 12 of the transfer device is driven in the Z direction (vertical direction) by a drive mechanism (not shown).

Further, in the figure, reference numeral 53 denotes a photosensor attached to the main body 12, and this photosensor 53 is turned on and off by a shutter 54 provided on the lower surface of the first arm 23. In other words, the above-mentioned mounting table 47
When the first arc 1'1 arm 23 is positioned so as to face each other on one of a pair of transport paths (not shown), that is, when the transfer device is in the initial state, the photosensor 53 activates the shutter 5.
4 to be turned off.

Next, a case will be described in which the 7% sea urchin carrier 51 is transferred from one conveyance path to the other conveyance path using the transfer device configured as described above. First, if the transfer device is in its initial state,
By driving this transfer device in the Z direction, the wafer carrier 51 that has been transported along one of the transport paths is placed on the mounting table 47 provided on the second arm 42 .

In order to transfer the wafer carrier 51 to the other transport path in this state, the first guard motor 14 is activated.

As a result, the first drive shaft 18 and the second boss portion 24 extending vertically from the middle of the first arm 23 are rotationally driven via the gear train.

When the first drive shaft 18 is rotationally driven, the third link plate 32c in the middle of the first main link plate 29 fitted to the upper end thereof rotates eccentrically. As a result, the first main link plate 29 reciprocates in its longitudinal direction, and the second link plate 32b provided at the other end rotates eccentrically.

When the second link plate 32b rotates eccentrically, the connecting shaft 35, which is provided so that its rotation center and axis coincide with each other, is rotationally driven. Thereby, the second arm 42 connected to the upper end of this connecting shaft 35 is connected to the connecting shaft 35.
It will rotate using the fulcrum as the fulcrum.

When the second arm 42 rotates about the connecting shaft 35, the third link plate 46c in the middle of the third main link plate 45 fitted onto the connecting shaft 35 rotates eccentrically. As a result, the third link plate 45 reciprocates in its longitudinal direction, so that the second link plate 46b provided at the other end of the third main link plate 45 rotates eccentrically and is fitted into its center of rotation. The shaft portion 48 of the mounted table 47 is driven to rotate.

On the other hand, when the second boss portion 24 is rotationally driven by the first geared motor 14 via the gear train, the second
The first arm 23 connected to the boss portion 24 is rotated. When the first arm 23 rotates, the second arm 42 rotates in the opposite direction in conjunction with the rotation. Since the speed ratio of the first arm 23 and the second arm 42 is set to 1:2, the first arm 23 is 1:2.
By rotating 80 degrees, the second arm 4 rotates 380 degrees in the opposite direction. As a result, even when the second arm 42 rotates, the wafer carrier 51 placed on the mounting table 47 moves in the direction of arrow A shown in FIGS. 1 and 3 without relatively changing the direction of rotation. It will be driven linearly. Therefore, since the mounting table 47 is driven from the state shown by the solid line in FIG. 3 to the state shown by the chain line in FIG. 3, the mounting table 47 is thereby positioned from one transport path to the other transport path. become. When the transfer device is driven downward in the Z direction in this state, the engagement flange 52 of the wafer carrier 51 placed on the mounting table 47 engages with a retaining portion (not shown) on the other transport path. Therefore, the wafer carrier can be transferred to the other transport path.

On the other hand, when the second geared motor 39 is operated to rotationally drive the first rotation shaft 18, the second
The third link plate provided in the middle of the main link plate 31 of
The link plate 33c is eccentrically rotated. As a result, the second main link plate 31 is reciprocated along its longitudinal direction, so that the second link plate 33b provided at the other end rotates eccentrically. Thereby, the second link plate 33
Since the hollow shaft 36 provided at the rotation center of b is rotated, the third link plate 46c provided in the middle of the third main link plate 45 fitted to the upper end of this hollow shaft 36 is eccentric. It will rotate.

When the third link plate 46c rotates eccentrically, the third main link plate 45 is reciprocated, thereby causing the second link plate 46b provided at the other end to rotate eccentrically. When the second link plate 46c rotates eccentrically, the mounting table 47 is rotated.

That is, if the first arm 23 and the second arm 42 are rotated by the first guard motor 14 to position the mounting table 47, and then the second guard motor 39 is operated, the mounting table 47 is placed on the mounting table 47. Wafer carrier 5
It is possible to control the rotational direction of the first rotation direction.

Note that in the above embodiment, the arm is divided into two, the first arm and the second arm, but it may be made into one arm without being divided.

Moreover, although the main body is driven in the Z direction to transfer the wafer carrier, the side on which the wafer carrier is transferred may be driven in the Z direction instead of the main body.

[Effects of the Invention] As described above, in the present invention, a workpiece mounting table rotatably driven by the parallel link mechanism is provided at one end of an arm formed by housing the parallel link mechanism in a sealed case, and The parallel link mechanism is driven by the parallel link mechanism, and the arm is rotationally driven. Therefore, by operating the parallel link mechanism while rotating the arm, it is possible to transfer the workpiece placed on the mounting table while controlling its posture. The device can be made smaller compared to a structure in which a stand is installed, and the drive mechanism does not run above the workpiece transfer direction.Furthermore, the parallel link mechanism is housed in a sealed case, so the workpiece etc. No dust will fall on the surface. Furthermore, when a workpiece is transferred to a magnetically levitated vehicle, the workpiece can be transferred without applying a load greater than the weight of the workpiece to the magnetically levitated vehicle, so that there is no adverse effect on the levitation state of the workpiece.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a vertical cross-sectional view of the entire device, Fig. 2 is a plan view, Fig. 3 is an explanatory diagram of the state of transferring a workpiece, and Fig. 4 is a parallel link mechanism. FIG. 5 is an explanatory diagram of a conventional transfer device. DESCRIPTION OF SYMBOLS 11... Drive mechanism, 14... First geared motor, 23°... First arm, 24... Second boss portion (second drive shaft) 28... First seal case, 29
...First main link plate, 31...Second main link plate, 39...Second guard motor, 42...Second arm, 44...Second sealed case, 45 ...Third main link plate, 47.
...Placement table, 51...Wafer carrier (work). Applicant's agent Patent attorney Takehiko Suzue Figure 4 Figure 5

Claims (1)

[Claims] an arm having a parallel link mechanism housed in a sealed case; a workpiece mounting table rotatably provided at one end of the arm and rotationally driven by the parallel link mechanism;
The present invention is characterized by comprising: a drive shaft connected to the other end of the arm to drive the parallel link mechanism; and a drive mechanism that rotationally drives the drive shaft and rotates the arm using the other end as a fulcrum. transfer equipment.