JPH01305533A - Transfer device - Google Patents

Abstract

PURPOSE:To operate it in various traces by connecting each arm freely in rotation to the end of a driving arm connected to each of two driving shafts and further connecting the arm freely in rotation so as to hold a substance to be transferred with one hand of the arm. CONSTITUTION:A holding means 37 to hold a substance to be transferred is constituted of a holding arm 35 and a cylindrical electrostatic chuck 41 fixed to one end of the holding arm 35. At the middle of the holding arm 35 is connected freely in rotation one end of a driving arm 33 by a shaft 35 and a bearing. To the other end of the holding arm 35 is connected freely in rotation one end of an arm 36 with a shaft 39 as the center. To the other end of the arm 36 is further connected freely in rotation one end of a driving arm 34 by a shaft 40 and a bearing. Each end of the driving arms 33 and 34 is fixed to a driving shaft 31 or 32, and the driving shafts 31 and 32 are connected to a step motor 30 through rotation introducing units 4. It can be operated smoothly in various traces in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a transport device, and particularly to a transport device for transporting thin plates such as semiconductor wafers.

(Prior art) In recent years, with the miniaturization of LSI devices, dust, which could previously be ignored, has become a problem, and there is a need for a transport device that generates less dust when transporting wafers, etc. . Generally, in order to suppress dust generation, the drive mechanism part of the transport device and the transport operation part are separated by a partition plate, and the transport operation mechanism part has large friction bells 1 to 1. It is constructed using only mechanisms with low friction, such as bearings, without using gears.

For example, as in the transport device shown in FIG. 16, a drive mechanism portion connected to a drive shaft 1 is separated from a transport operation mechanism portion by a partition plate 2 which also serves as a vacuum wall surface of a vacuum chamber. This drive shaft 1 is driven via a rotary shaft seal mechanism 4 such as a magnetic fluid seal. An arm 5 is connected to the drive shaft 1, and a tray-shaped holding means 6 for holding an object to be transported such as a semiconductor wafer is provided at the tip of the arm 5. Therefore, the object to be conveyed is the drive shaft 1.
It is transported by driving the arm 5 fixed to the drive shaft 1 and rotating the arm 5 fixed to the drive shaft 1.

However, if the conveyance distance is increased, the length of the arm 5, that is, AP must be increased, and the turning radius becomes larger.

For this reason, there is a problem in that the conveying device is likely to interfere with other devices installed around it. In addition, since the turning radius becomes large, when this transfer device is used in a vacuum processing device, the size of the vacuum chamber becomes large, and the openings such as the loading/unloading port also become large, which reduces the reliability of the vacuum seal at these openings. There was a problem that it took a long time to evacuation.

Further, as the conveying operation mechanism section, a link mechanism is adopted as disclosed in JP-A-61-87351 and JP-A-61-3341.7.
No. Publication is known.

As shown in FIG. 17, the former conveyance mechanism has an arm 9.8 having a length equal to the axis 7.8. ]0 are connected to each other, and the ends of these A1% 9 and 1.0 have equal length A], 1. ．． 1.2 are rotatably connected to each other.

arm! , 1.12 are each rotatably connected to the holding arm 14. The drive shafts 7, 8 are moved Iψ by an I drive mechanism inside the box 3, which is the upper surface or the partition plate 2, through a rotary seal mechanism, and the drive shafts 7, 8 rotate in opposite directions at the same angle.

The transfer device having such a configuration has arm 9 and arm A.
], O always rotate in the opposite direction, arm 11 rotates in the opposite direction to the rotation direction of art 9 about the axis of the tip of arm 1%9, and arm]2 rotates in the opposite direction to the rotation direction of arm 10.
The holding arm 14 rotates in the opposite direction to the rotating direction of the arm 10 around the axis at the tip of the arm 10, and the holding arm 14 always faces the same direction due to the assembly lever mechanism, so the holding center of the holding arm 14 moves in a straight line and the transfer device It has the advantage of having a trajectory that is less likely to interfere with other devices around it. However, this transfer device cannot move the holding arm 14 beyond the straight line connecting the drive shafts 7 and 8. Therefore, in order to transport the objects to both sides of this transport device, it is necessary to further provide a rotary table 16 that rotates the entire transport device. It is necessary to provide two drive shafts that are vacuum-sealed inside the rotary shaft, which has the disadvantage of complicating the structure of the vacuum seal part. need to be higher.

Furthermore, if the distance between the axes of the arms changes due to thermal expansion of the arms, the arms 9 and 10 will not be able to rotate more than 90 degrees, or will require a large driving torque to rotate more than 90 degrees. There is a drawback that a large load is applied to each arm and the connecting shaft of the arms.

The latter conveyance operation mechanism is connected to the drive shaft 1 as shown in FIG.
An arm 18 is connected to 7, and an arm 20 is connected to a shaft 19 rotatably provided on the partition plate 2. A holding arm 21 is rotatably attached to the tip of the arm 18.
The intermediate portions of the holding arm 21 are connected to each other, and the distal end portion of the arm 20 is further rotatably connected to one end portion of the holding arm 21. The drive shaft 17 is connected to the partition plate 2 via the rotary shaft seal mechanism 4.
It is driven by a drive device located below. A1
The inter-axle distances AB, B5, and DE of %18.21.20 and the inter-axle distance AE between the drive shaft 17 and the shaft 19 satisfy the following relationship. AB+BD>DE+AE. In this example, an electrostatic chuck 22 is provided at the tip of the holding arm 21 to hold the object to be transported. The conveyance device having such a configuration has a rotational direction of the arm 18 and an arm 2.
0 is always the same, but since the holding arm 21 rotates around the tip of the arm 18 in the same direction as the rotation direction of the arm 18 or in the opposite direction, the surrounding Interference with equipment is likely to occur.

FIG. 19 shows the distance between the axes of arm 18 A B = 350+nm and the distance I between the axes of arm 2 in this transfer device.
n=37.5nlTl, 7-mu20(7) center distance D
E = 31.7.5mn, drive shaft 17 and shaft 1
Distance between the axes of A18 A E = 67.5nwn, Distance between the holding center and the axis of the tip of A18 B P = ], 50m
For the specific example of n+, the relationship between the rotation angle of the arm 18 and the inclination angle of the line segment connecting the holding center of the arm 21 and the axis of the tip of the arm 18 with respect to the straight line connecting the drive shaft 17 and the shaft 19 is expressed as follows. This is a graph showing. In the positive slope portion of this graph, the rotation direction of the arm 18 and the rotation direction of the holding arm 21 are the same, and in the negative slope portion of this graph, the respective rotation directions are opposite. As shown in this specific example, in this conveyance device, the rotational direction of the holding arm 11 changes midway. For this reason, the conveyance trajectory becomes undulating, and the rotation trajectory around the first drive shaft 17 is in the region where the holding arm 21 rotates in the same direction as the rotational direction of the arm 18 with the tip of the arm 18 as the axis. They have similar trajectories, and have the disadvantage that interference with other devices around the conveying device is likely to occur. FIG. 20 shows an example in which this transfer device is applied to a vacuum processing device. The transport device is located in the preparation room 23.
Objects are transported between a processing chamber 24 adjacent to the preparation chamber 23 and the atmosphere. The preparation room 23 has a processing room 2.
A gate valve 25 is provided on the 4 side, and an atmospheric valve 26 is provided on the atmospheric side.
6 is closed, the preparation chamber 23 is evacuated, the gate valve 25 is opened, and the object to be transported is transported into the processing chamber 25.

The holding arm 21 is held by pushers 27.28 and is configured to move below the object to be carried. It's being done. This conveyance device is
It has the disadvantage that interference with other surrounding devices is likely to occur, and even if the pusher 27 is arranged to extend as far as it can stably support the conveyed object, the tip of the holding arm 2 should not be made thin or short. Since interference with the bushing 27 occurs, there is a drawback that the area of the electrostatic chuck provided at the tip of the holding arm becomes small. Further, in order to avoid interference with the arm 18, the width of the atmospheric valve 26 has to be increased.

In addition, as shown in FIG.
A brake mechanism is provided to suppress the rotation of the
In a transfer device configured to satisfy the relationships A and E, the holding arm 21 always rotates in the opposite direction to the rotational direction of the arm 18 around the tip of the arm 18, and is connected to other devices around the transfer device. Interference is less likely to occur, and there is no undulation in the trajectory. However, in a conveying device having such a configuration, if the distance between the axes of the arms changes due to thermal expansion of the arms, the trajectory will change drastically to another curved trajectory, or the arm 18 will move to the drive shaft 17. and axis 1
The drawback is that it cannot be rotated beyond the straight line connecting 9.

(Problems to be Solved by the Invention) Conventional conveying devices have problems such as easy interference with other devices installed around the conveying device, such as double-unit conveyors, and difficulty in smooth conveyance due to thermal expansion, etc. However, when the transfer device is used in a vacuum processing device, there are problems such as the need to increase the size of the vacuum processing device.

Therefore, the present invention aims to solve the above problems.

It generates less dust, has a trajectory that does not easily interfere with other equipment around the transport device, can be stored in a small space, and transports objects by passing through a straight line connecting two fixed rotation axes. It can be transported, and even if the distance between the arm axes changes slightly due to thermal expansion, the trajectory will not change drastically or the rotation of the arm will not be hindered, allowing smooth operation. The purpose is to provide a conveyance device that can.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the second object, the present invention connects a drive arm to each of two drive shafts, and rotatably connects each arm to the tip of these drive arms. Furthermore, the present invention provides a conveyance device in which these arms are rotatably connected to each other and one of these arms is provided with a means for holding an object to be conveyed.

(Function) By rotating the drive arms connected to the drive shaft in the same direction, the first and second connection points between each drive arm and the third connection point between the arms form a triangle with the vertices of each of them. An arm formed and operative and having retaining means connected to the drive arm can always be rotated in a direction opposite to the drive arm. The object placed on this holding means can be moved through a line connecting one drive shaft.

Also, if the distance between the arm axes changes due to thermal expansion, etc.
Although the mutual angle of the arms changes slightly, the locus does not change drastically or the rotation of the arms is inhibited, and smooth movement is always possible. Furthermore, it has two drive shafts 31, 32 and can be operated with various trajectories.

(Example) A first example of the present invention will be described with reference to FIGS. 1 to 4. Reference numeral 37 denotes a holding means for holding an object to be transported, and this holding means 37 is composed of a holding arm 35 and a disc-shaped electrostatic chuck 41 fixed to one end of this holding arm 35. One end of a drive arm 33 is rotatably connected to a shaft 38 by a bearing in the middle of the holding arm 35 . One end of an arm 36 is connected to the other end of the holding arm 35 so as to be rotatable about a shaft 39. The other end of the arm 36 is further rotatably connected to one end of the drive arm 34 to a shaft 40 by a bearing.

The other end of each drive shaft AS:3:3.34 is a drive shaft 3].

32, and these drives 4+1131,3
2 extends below the partition plate 2 via a vacuum rotating machine 4, and is connected by a timing pulley 30a. One drive shaft is connected to a steering wheel 30 disposed below the partition plate 2. Note that the center of the electrostatic chuck 41, the shaft 38, and the shaft 39 are the drive arm 33.
When the drive arm 34 overlaps with the drive arm 34, the electrostatic chuck 41 is arranged offset from the same straight line so that the center of the electrostatic chuck 41 overlaps with the drive arm 34.

Further, this embodiment is used in a vacuum processing apparatus, and the partition plate 2 also serves as a vacuum wall (not shown) of a vacuum chamber. The partition plate 2 is provided with grooves for the gas scaler 1 and mounting bolt holes so that the conveying device can be disassembled.

2 and 3 are plan views of the conveyance device shown in FIG. 33.34,
The holding arms 35 are shown in an overlapping state. FIG. 4 shows an example in which this transfer device is attached to a vacuum processing device.

The driving device portion of the transport device such as the step motor 30 is separated from the space in which the objects to be transported are transported by the partition plate 2 and the protection plate around the vacuum processing device. A holding arm 35 and a drive arm 33 that transport objects.
34. The transport operation mechanism part consisting of the arm 36 is connected by shafts and bearings, and does not use mechanical elements that tend to generate dust such as pulleys, belts, gears, etc., so there is little friction and less dust is generated. . Therefore, this conveying device can minimize the generation of dust in the space where the objects to be conveyed are conveyed.

In the conveying device of this embodiment, since the shafts 38 and 40 at the tips of the drive arms 33 and 34 are connected by the holding arms 35 and the arms 36, the shafts 38 pass through the straight line ``2'' connecting the drive shafts 31 and 40. In addition, the shaft 40 is connected to the drive shaft 32 and the shaft 38.
It can pass on the straight line connecting . Further, since the drive shafts 31 and 32 are connected by the timing bells 1 to 1,
The second drive arms 33,34 rotate in the same direction. Therefore, as shown in Fig. 3, axis 3], 38.40,
The shafts 32, 38, 40 can be sequentially or simultaneously passed through a state in which they are lined up in a straight line, and the conveyed object can be moved by the drive shafts 31.
32, and can be transported by passing through the straight line connecting 32. Further, the conveying device of this embodiment can select the rotation angle of the drive arm 33.34 by selecting the ratio of the number of teeth of the timing pulley.
8.40 and the shaft 32.38.40 can be operated sequentially or simultaneously through a two-linear state, so that the direction of rotation of the holding arm 35 can be controlled by the drive arm 33.3.
The direction of rotation can always be opposite to the direction of rotation in step 4.

Therefore, this conveyor has a conveyance trajectory without undulations, and with a relatively short arm length and a small rotation angle of the drive arm, it is possible to obtain a large conveyance distance, and other devices installed around it can achieve a long conveyance distance. It has a trajectory that is difficult to interfere with. Further, the rotational directions of the drive arms 33 and 34 of the transfer device of this embodiment are the same, and the rotation angle ratio of the drive arms 33 and 34 is the distance between the axes BC and CD of the axes 38, 39 and 40 of the arms 35 and 36. is the length of two sides of the triangle, and drive arm 3
The distance between the axes 38 and 40 at the tip of 3.34 is determined on the condition that a triangle can be formed with the mound of the mouth being the length of the other side of the triangle. Therefore, in this transfer device, if the distance between the axes of each arm changes slightly due to thermal expansion, the apex angle of the triangle with the axis 38, 39, 40 as the apex will change slightly, and the trajectory of the transferred object will change slightly. The trajectory of the changing object does not change drastically or the rotation of the arm is not hindered, so it can always operate smoothly. This transfer device is applied to transfer inside a vacuum processing device, and in a vacuum, heat cannot be transferred by convection, so by transferring the transferred object that has been heated during processing, there is a temperature difference between each arm. may occur, and each arm may thermally expand non-uniformly, but even in such a case, smooth operation is possible.

Furthermore, even if the distance between the axes of the arms changes slightly, smooth operation is possible, so there is plenty of room for assembly, and assembly is easy.

The conveyance device of vacuum processing equipment is often disassembled and reassembled periodically for cleaning and inspection.
It is possible to shorten the working time and increase the operating rate of the device. In addition, this conveyance device, as shown in Fig. 3,
The drive arm 33, 34 and the holding means 37 portion of the holding arm 35 can be stacked in a straight line and folded, allowing storage in a small space.

Figure 4 shows an example in which this embodiment is used in a vacuum processing apparatus that is almost the same as the vacuum processing apparatus shown in Figure 1. This is the locus of the holding center point. The dimensions are the distance A between the axes of the drive arm 33.
B = 30On+m, distance between the axes of the holding arm 35 BC = 60 mm, distance between the axes of the arm 36 CD = 30
m, distance between the axes of the drive arm 34 DE = 183■, distance between the axes of the drive shaft 32.32 A E = 155nwn,
Distance between the holding center of the holding arm and the shaft 38 B P = 1
35nwn, holding center and axis of holding arm 38. Angle formed by shaft 39/CBP=1.55.5° Drive arm 3
The ratio of the rotation angle of the drive arm 34 to the rotation angle of the drive arm 34 is 1.4 times.

According to the conveyance device having the above-mentioned dimensions, there is no undulation as shown in the figure, and the conveyance trajectory is close to a straight line = 15-. FIG. 5 shows the relationship between the rotation angle of the first drive arm 33 with respect to the straight line connecting the drive shafts 31 and 32 and the angle of the line connecting the holding center point of the holding arm 35 and the shaft 38 with respect to the reference line. As shown in this diagram, according to this embodiment, the slope is always negative. The fact that the slope is always negative indicates that the direction of rotation of the first drive arm 33 and the direction of rotation of the holding arm 35 about the axis 38 are always opposite. Therefore, this transport device is less likely to interfere with other devices around it. In other words, the advantage is that the width of the atmospheric valve 26 can be reduced, and the buttons 27 can be equally spaced as shown in FIG. The advantage is that it can be made larger.

As described above, according to this example, less dust is generated,
It is difficult to interfere with other equipment around the transfer device, allows objects to be transferred beyond the transfer device drive part, and even if the distance between the arm axes changes slightly due to thermal expansion, the trajectory will not change drastically. Alternatively, it is possible to provide a conveying device that can operate smoothly without hindering the rotation of the arm. Furthermore, it is possible to provide a conveyance device that can selectively operate on various trajectories and can stop accurately even when the arm expands thermally. Furthermore, it can be applied to vacuum processing equipment, and because it generates little dust, it has the advantage of providing vacuum processing equipment with high yields, is less likely to interfere with other equipment around the transport equipment, and can be stored in a small space. Because of this, the size of the vacuum chamber can be reduced, the evacuation time of the preparation chamber can be shortened, and a vacuum processing equipment with high processing capacity can be provided.

Since the size of the opening of the gate valve etc. can be reduced, there is an overall effect of providing a vacuum processing apparatus with highly reliable vacuum sealing.

Next, a second embodiment of the present invention will be described with reference to FIGS. 6 to 8. Note that the same parts as in the first embodiment are denoted by the same reference numerals, and a description thereof will be omitted.

The holding means 37 includes a tray 43 in which a notch is formed to avoid interference with other devices such as a bushing, and this tray 43.
The holding arm 35 has one end fixed to the holding arm 35.

FIG. 7 is a plan view showing an example in which the second embodiment shown in FIG. 6 is applied to a vacuum processing apparatus, and the first embodiment shown in FIG.
This was carried out using the dimensions of the example. Obon 4
The cutout portion 3 is formed so as to avoid the four bushings 28 of the processing chamber 24 and the bushing 29 having a vacuum suction function in the atmosphere.

Even if such a notch is formed, the protrusion of the tray remains on half the circumference, and can hold objects to be transported.

That is, by having the structure as described above, the holding means 37
Since the insertion positions into the bushings are approximately in the same range, the conveyed object is not limited to an electrostatic chuck, but may be held by a tray or the like having a cutout in a part. In addition, it has a locus that is unlikely to interfere with other devices around it, the size of the holding means can be made large, and a variety of structures can be selected for the holding means.

FIG. 8 shows an example in which a transfer device having the following dimensions is used in a vacuum processing apparatus in which a gate valve 25 and an atmospheric valve 26 are arranged at right angles. The dimensions are the distance between the axes of the drive arm 33 A+
3 = 215n, distance between the axes of the holding arm 35 B C-
60mm, center distance CD of Ar1136 -30mm
.

Distance between axes of drive arm \34 D E = 191. mm
, drive shaft 31°32 axis 1iJj distance A E -84
nyn, distance B P between the holding center of the holding arm and the axis 38
= 1. ], 5+nm, holding center of holding arm and axis 38. Angle Zc B P = ], 5] formed by axis 39
', the ratio of the rotation angle of the l drive arm 34 to the rotation angle of the drive arm 33 is 1.15.

The trajectory of the conveyor device with these dimensions is close to a circular arc, but the drive shafts 31 and 32 are located near this trajectory, and the drive shaft is located near the center of rotation of this arc. The rotation direction of the drive arms 33° 34 and the rotation direction of the holding arm 35 around the shaft 38 at the tip of the drive arm 1133 are always opposite, and there is no waviness.
It has a trajectory that makes it difficult to interfere with other devices around it. In this way, this embodiment can also be applied to a vacuum processing apparatus in which the gate valve 25 and the atmospheric valve 26 are arranged at right angles, and in this case, the vacuum chamber can be arranged compactly.
The width dimension of the entire vacuum processing apparatus can be reduced.

Next, a third embodiment of the present invention will be described with reference to FIG. 9. Note that the same parts as those in the second embodiment are designated by the same reference numerals, and a description thereof will be omitted.

In this embodiment, the driving arm 33 is provided above the holding arm 35, and the shaft 38 is provided with a spacer 44 that forms a distance between the driving arm 33 and the holding arm 35. With this configuration, the object to be transported can be passed under the drive arm 33. In the first and second embodiments, since the drive arm 33 and the arm 36 are at the same height, the dimensional specifications such as the distance between the axes and the rotation angle ratio of the drive arm are the same as the length of the drive arm 33. The design was made to avoid interference with the short arm 36, but according to the conveyance device according to this embodiment, there is no interference between the arms, allowing for greater freedom in selecting dimensions and selecting a wider variety of conveyance trajectories. can do.

Further, a fourth embodiment will be described with reference to FIG. 10. In this embodiment, the partition plate 2 is one part of the transport mechanism for the transported object.
One end of an arm 36 is rotatably connected to the lower side of the drive arm 34 about a shaft 40 . The other end of the arm 36 is rotatably connected to one end of the holding arm 35 via a spacer 44 disposed below the arm 36 about a shaft 39. A drive arm 33 is arranged below the middle of the holding arm 35 and is connected to the drive arm 33 so as to be rotatable about a shaft 38 . A pin 45 having a tapered tip and a thick base is installed on two surfaces of the other end of the holding arm 35 to form a holding means. In the transfer device according to this embodiment, the transfer operation mechanism consisting of an arm and a holding means is suspended from above, so there is one preparation chamber for one processing chamber, and one preparation chamber for one preparation chamber. It can be used in a vacuum processing apparatus in which two transfer devices are arranged, and an inexpensive and compact vacuum processing apparatus can be provided. Further, since the positional relationship of the arms in the thickness direction can be changed arbitrarily by changing the length of the spacer, etc., various choices can be made depending on the transportation method. Furthermore, in this embodiment, since the holding means is a pin 45 that corresponds to a fixing recess or hole formed in the transported object, even if the stopping position of the transport device changes slightly due to thermal expansion of the arm, the It has the advantage of being able to reliably transfer objects. The conveying device of the present invention includes:
Even if the shape of the transported object is different, the same effect can be achieved.

FIG. 11 shows a fifth embodiment of the conveying device according to the invention. This embodiment has a structure in which the arm 36 is provided with a holding means, and compared with the third embodiment, the holding means 37 is
The arms provided with the two are different, but the rest are the same. That is, in this example, the arm 36 becomes the holding arm,
The arm 35 is a short arm. In the embodiment described above, the drive arms 33, 34 rotate in the same direction,
The distance BD between the shafts 38 at the tip of the drive arm 33 and the shaft 40 at the tip of the drive arm 1134 changes with the conveyance operation. The value of this distance between the axes BD is 38.39.40
Operates within the range that can form a triangle with vertices. Therefore, in this embodiment in which the arm 36, which is one side of the triangle, is provided with a holding means, the arm 36, which is the other side of the triangle, is provided with a holding means.
Although the locus of the holding center is different in the case where the holding means is provided in 5, the same operation and effect are achieved.

Further, as a specific example of the above embodiments, only a specific example in which the distance between the axes of the arm 36 is the smallest compared to the distance between the axes of the other arms has been given, but this is based on the position shown in FIG. This is a necessary measure to avoid interference between the drive arm 33 and the arm 36 when the As will be described later, the longer the distance between the axes of the arms 35 and 36, the wider the selection range of the locus, but as long as the required trajectory is obtained, the distance between the axes of the arms 35 and 36 is short enough.

In the conveying device of the present invention, a triangular shape having three axes 38, 39, 40 of a shaft 39 rotatably connecting the shaft 38, 40 at the tip of the drive arm 33, 34 and the arm 35, 36 as vertices is formed. It operates by rotating the drive arm 33,34 within the possible range. In the embodiment described above, the drive shaft is connected by a timing pulley, and the drive arm 33
．． By giving a certain proportional relationship to the rotation angle of 34, the condition for forming this triangle is satisfied.

The conditions under which this triangle can be formed are arm 35.36-2
The following relationship holds true between the inter-axial distances BC and CD of 3 to 3 and the inter-axial distance TE of the shaft 38.40 determined by the rotation angle of the drive arm 33.3/I.

1BC-C100l<BD<B and +ζ■ Equation 1 This relational expression also indicates that the apex angle of the triangle with axis 3g and 39.40 as apex exceeds 00 and is less than 80°. .

In Figure 12, the distance between the axes of the drive arm 33 AB = 300 m.
m, distance between the axes of arm 35, positive δ = 601, arm 36
For a specific example, the distance between the shafts CD = 30 nn, the distance between the shafts of the drive arm 34 = 183 mm, and the distance between the shafts of the drive shaft 31.32 □ = I positive ε- and negative = 60-30
= 30 n listens.

Maximum center distance: J 602+302-2 X60X30Xcos1
Drive arm 33 when 20° = 73.4mm.
34 is indicated by diagonal lines in relation to the rotation angle of the drive arms 33, 34 with reference to the straight line connecting the drive shafts 3, 32. If the arms 35 and 36 are fully opened to 80 degrees, the next closing operation will not proceed smoothly, so this example is given stricter conditions than the conditions in the first equation. The straight line shown in FIG. 12 shows the relationship between the rotation angles of the drive arms 33 and 34 in the specific example of the first embodiment. Figure 13 shows the drive arm 33.3
12 shows the movement range of the holding center when 4 is controlled within the shaded range in FIG. Figure 12.

FIG. 13 shows that the conveying device of the specific example of the first embodiment has an apex angle of the triangular shaft 39 with the axes 38, 39, and 40 as vertices exceeding Oo and less than 120° at all points in its operation. This shows that there is a possibility of smooth operation.

FIG. 12 further shows that the rotation angles of the drive arms 33 and 34 do not necessarily have to be proportional, and it is also possible locally to rotate the drive arms 33 and 34 in opposite directions.
From a rough perspective in a large range of rotation angles,
This shows that the same effects as in the previous embodiment can be obtained as long as the drive arms 33 and 34 are rotated in the same direction.

In addition, since the drive mechanism section and the transportation mechanism section for the transported object can be separated by the partition plate 2, even if the drive mechanism section uses gears instead of the timing bell 1-, it will not affect the transported object. The operation and effect are the same even if a DC motor is used instead of a step motor and stopped by a limit switch. A rotary actuator may be used instead of a DC motor. Since the rotation angles of the drive arms 33 and 34 are proportional, this embodiment has the advantage of being inexpensive.

FIG. 14 shows a sixth embodiment of the invention. drive shaft 31,
32 are each connected to a separate step motor via a rotary shaft sealing mechanism 4. The two step motors are controlled by a microcomputer or the like so that their rotation angles are related to each other. The first equation holds true for this control range, and the axis 38.
39.If the vertex angle of the triangle with 40 as the vertex exceeds Oo, then 18
If the angle is controlled to be less than 0°, the action and effect will be the same.

Furthermore, if temperature sensors are provided on the arms 33 to 36, the amount of thermal expansion of the arms is calculated by a microcomputer, and the rotation angle of the drive arms 33 and 34 is controlled according to changes in the distance between the axes, the thermal expansion of the arms can be reduced. Even in some cases, it is possible to improve the stopping position accuracy.

Further, by measuring the stop position error, calculating and controlling the correction amount of the rotation angle of the drive arm using a microcomputer, it is possible to improve the stop position accuracy.

FIG. 15 shows the distance between the axes A and B of the drive arm 33.
0m, distance between the axes of arm 35 B C=/1Onn+,
Distance between shafts of arm 36 CD = 4On+m, distance between shafts of drive arm 34 100E = 230nwn, drive shaft 31
．． Distance between the axes of the holding arm AE = 65 m, distance B P = 135 mm between the holding center of the holding arm and the axis 38. The shaft 38 at the tip of the drive arm 33.34 in a specific example where the angle formed by the shaft 39/CBP=109.5°
．． The distance BD of 40 is the minimum value BD, 4g=J402+402-2X40X4
0Xcos(15)=]Omn maximum value B Dmax"'
/402+402-2X40X40Xcos(150°
)=771ml, yAIil! I]
Arm 3: Shows the movement range of the holding center when controlling the rotation angle of L34.

When the distance BD becomes zero, that is, when the axes 38.40 overlap on one axis, the position of the arm 35.36 becomes unstable, and when the arm 35.36 is fully opened, the next closing operation occurs. Therefore, the region shown in FIG. 15 is determined to satisfy conditions that are stricter than the conditions of the first equation. The transfer device of this specific example has a wide movement area and can be applied to a vacuum processing device having two processing positions.

In addition, it has two drive axes and can move within a planarly spread area, so by controlling the rotation angle of the two drive arms in relation to each other, it can be transported to any position within the area. There are advantages that can be achieved.

Furthermore, if the holding arm is made of a material with low thermal conductivity, the thermal expansion of the arm can be reduced, and if each bearing is provided with a magnetic fluid seal to seal out some dust generated from the bearing, the generation of dust can be further reduced. You can do less.

〔Effect of the invention〕

As described above, according to the present invention, there are two drive shafts, a first arm and a second arm connected to the drive shafts.

~28- A third arm connected to the first arm, a fourth arm connected to the third arm and the second arm, and a holding means provided at the 47th-, and each arm is rotatable. Because they are connected, the object to be transported can be transported beyond the drive unit, and it is less likely to interfere with other devices placed around it. Furthermore, even if the distance between the arm axes changes slightly due to thermal expansion, the object to be transported can be transported smoothly. Can be transported. Further, since the conveyance device of the present invention allows selection of various dimensions, various conveyance trajectories can be selected depending on the vacuum processing apparatus.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a first embodiment of the conveying device according to the present invention, FIGS. 2 to 4 are plan views, and FIG. 5 shows the relationship between the inclination angle of the holding means and the rotation angle of the drive arm. Diagram, 6th
The figure is a perspective view of the second embodiment, Figures 7 and 8 are plan views, Figure 9 is a perspective view of the third embodiment, Figure 10 is a perspective view of the fourth embodiment, and Figure 11 is a perspective view of the fourth embodiment. The figure is a perspective view of the fifth embodiment;
Figure 2 is a diagram regarding the rotation angle of the two drive arms, the first
3 is an explanatory diagram showing the movable area of the holding center of the holding means, FIG. 14 is a perspective view of the sixth embodiment, FIG. 15 is an explanatory diagram showing the movable area of the holding center, and FIGS. 18th
17 is a plan view of the conventional conveying device, FIG. 19 is a diagram showing the relationship between the inclination angle of the holding arm and the rotation angle of the arm, and FIG. 20 is the conventional conveying device. It is a top view explaining a conveyance locus. 2・Partition plate 4・Rotary shaft seal mechanism 30・Step motor 31, 32・Drive shaft 33, 34・・Drive arm 35.36・Ar 1137 Holding means
38.39.40・Axis agent Patent attorney Nori Chika
Figure 11 Relationship between the rotation angle of the gravity arm 33 and the rotation angle of the drive arm 34 due to the timer 77' bolt. Rotation angle based on 17 and fbk/q as well

Claims (3)

[Claims] (1) Two drive shafts, a first arm and a second arm each having one end connected to these drive shafts and rotating together with the drive shaft, and a first arm and a second arm rotatably connected to the other end of the first arm. It is characterized by having a third arm, a fourth arm rotatably connected to the third arm and the second arm, and a means for holding an object to be transported provided on the fourth arm. Conveyance device. (2) The first arm and the second arm are connected to a line segment connecting the connecting point between the third arm and the fourth arm and the connecting point between the third arm and the first arm, and the third arm and the fourth arm. The conveyor according to claim 1, wherein the conveyor rotates so that the angle formed by the connecting point with the arm and the line segment connecting the connecting point between the fourth arm and the second arm is always less than 180°. Device. (3) The drive shaft is erected at a predetermined interval by extending a partition plate through a rotary shaft sealing mechanism, and is rotated by a drive mechanism installed in this extension. 1. The conveyance device according to 1.