JP2638623B2 - Wafer handler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a wafer handler.

(Prior Art) In a semiconductor manufacturing process, for example, a wafer handler is used to transfer a wafer housed in a cassette to a wafer processing apparatus.

A typical example of this type of wafer handler is a handler called a flag leg method (Japanese Patent Application Laid-Open No.
-71383, JP-A-61-90887, JP-A-61-90903, JP-A-61-908
99344, JP-A-61-99345, JP-A-61-160949, JP-A-61-1
84841, JP-A-61-278149, JP-A-62-21644, JP-A-62-1
61607, JP 62-161608, JP 62-21649, JP 62-4
5038, JP-A-62-41129, JP-A-62-150735).

As shown in FIG. 7, the handler comprises a wafer supporting member 1 capable of mounting a wafer on a surface, and a pair of first arm members 2, 2 rotatably connected to the wafer supporting member 1. And a pair of second arm members 3, 3 whose one end is rotatably supported by the first arm members 2, 2. Then, a first pulley 4 is provided on a drive shaft provided at one end of the second arm members 3, 3.
A second pulley 5 is provided on a rotating shaft connecting the first and second pulleys 3, and a ratio of diameters of the first and second pulleys 4, 5 is set to 2: 1, and a belt 6 is provided between the two pulleys 4, 5. Is crossed over. Also,
In order to prevent the wafer support member 1 from freely rotating with respect to the first arms 2, 2, a configuration in which a gear (not shown) is engaged is adopted.

(Problems to be Solved by the Invention) According to the above-described flag leg type wafer handler, the movement of the joint portion of this arm is achieved only by connecting the first and second arm members arranged in parallel on the same plane. Since the position is not uniquely determined, the degree of freedom in only one direction of the wafer support member 1 cannot be ensured, and it is indispensable to use the first and second pulleys 4 and 5 and the belt 6. A gear must be used between the first arm member 2 and the first arm member 2 to restrain the free rotation of the wafer support member 1.

As described above, in the above configuration, the number of constituent members is relatively large, and cost increase is inevitable. In addition, since a gear is used, the backlash at the time of gear engagement causes the handler to have backlash.

The present invention has been made in view of the above circumstances, and it is possible to obtain a degree of freedom of linear movement in only one direction of a wafer support member while reducing the number of constituent members, and the configuration is simple and inexpensive. It is an object to provide a wafer handler.

[Structure of the Invention] (Means for Solving the Problems) A wafer handler according to the present invention supports a wafer support member at one end of each of a pair of articulated arms, and each of the pair of articulated arms. The wafer supporting member is linearly moved by rotating the other end of one of the articulated arms so as to intersect the moving plane.

Then, in order to linearly move the wafer support member to both sides of the position where the pair of articulated arms are arranged, it is preferable to arrange the pair of articulated arms at a position where they do not interfere with the wafer support member when moving in the above two directions. . Further, the entire wafer handler can be configured to be rotatable so that one end of the wafer support member can be disposed on the opposite side. Further, a device that can support a wafer at both ends of the wafer support member is preferable. . Further, when the wafer support member moves in both directions, it is possible to adopt a configuration in which when at least a plurality of arms constituting the multi-joint arm overlap, the overlap is released by applying an external force.

(Operation) A wafer supporting member is attached to one end of each of the pair of articulated arms to restrain the ends, and the pair of articulated arms is arranged so that the movement planes of the pair of articulated arms intersect. When the other end of the arm is rotationally driven, the position of the joint portion is uniquely determined by the constraint between the pair of articulated arms, and therefore, the degree of freedom of the wafer support member is desired to linearly move the wafer support member. Only one direction.

This will be described with reference to FIG. 5 in which the mechanism of the present invention is most simplified and schematically described.
Has arms 10a and 10b having three points a, b and c as joints, and a second articulated arm 2 paired therewith also has three points a, b and c jointed similarly. It has arms 11a and 11b as parts. If one of the planes 12 attached to one end of each of the first and second articulated arms 10 and 11 is used as a wafer support member, any one of the arms 10a, 10b, 11a, and 11b is rotated. The wafer support member 12 is constrained and moved only in the vertical direction in FIG.

As a result, it is not necessary to provide another member for securing the degree of freedom in only one direction, so that the number of members can be reduced, and since no gear is required, the backlash of the handler due to the backlash occurs. There is no.

Hereinafter, an embodiment in which the present invention is applied to a semiconductor wafer wafer handler will be specifically described with reference to the drawings.

In this wafer handler, as shown in FIGS. 1 and 2, a pair of articulated arms 20, 30 are arranged so as to be inclined such that their movement planes intersect. And an inclined portion 42 whose both ends are inclined at the same angle as the articulated arms 20, 30,
An arm connecting member 40 constituted by a horizontal portion 44 formed therebetween is provided, and the inclined portions 42, 44 are rotatably supported by moving ends of the pair of articulated arms 20, 30.
On the arm connecting member 40, tweezers 50 as an example of a wafer supporting member are fixed along a direction orthogonal to the longitudinal direction of the arm connecting member 40. In addition,
The tweezers 50 have vacuum suction portions 52, 52 that can support the wafer 60 at both ends by, for example, vacuum suction.

Next, details of the pair of articulated arms 20, 30 will be described.

The articulated arms 20, 30 have the same external configuration except for the drive system. That is, one multi-joint arm 20 is composed of a first arm 22 and a second arm 24, and similarly, the other multi-joint arm 30 is also composed of a first arm 32 and a second arm 34, It has a structure having three joints (a, b, c) that make both ends of each arm rotatable. One end of the first arms 22 and 32 is referred to as a first joint a, and a connecting portion between the first and second arms is referred to as a second joint b.
The connecting portion between the inclined portions 42, 42 and the second arms 24, 34
Assume joint c.

The first joint a side of the pair of articulated arms 20, 30 is connected to the slopes 72, 72 of the base 70 having the slopes 72, 72 inclined at the same angle as the inclination of the pair of articulated arms 20, 30. 72 rotatably supported. The inclined surface 72 on the articulated arm 20 side is further formed to extend obliquely downward, and this area is used as a mounting portion 74 of a motor 80 for driving the first arm 22 of the articulated arm 20.

In addition, the base 70 uses a vertical
2 can be rotated in the θ direction.

Next, regarding the drive system of the pair of articulated arms 20, 30,
This will be described with reference to FIG.

The wafer handler according to the present embodiment has one articulated arm.
A drive system is provided only on the 20 side, and when the one multi-joint arm 20 is driven, the other multi-joint arm 30 follows the drive system, and the tweezers are held while the two multi-joint arms 20, 30 are constrained to each other. Would move 50. The tweezers 52 move while maintaining a horizontal state for any movement.

First, as a drive system of the articulated arm 20, a first pulley 82 is fixed to the output shaft of the motor 80. On the other hand, a second pulley 86 is fixed to the first joint a on the rotation shaft 84 of the first arm 22. A belt 88 is provided between the second pulley 86 and the first pulley 82. Has been passed over. As a result, when the motor 80 is driven to rotate, this rotation output becomes the first output.
Is transmitted to the rotating shaft 84 of the first arm 22 via the pulley 82, the belt 88, and the second pulley 86, and the first arm is driven to rotate about the rotating shaft 84.

According to the configuration of the present embodiment, the one articulated arm 20
By rotationally driving the first arm 22, the moving position of each joint of the pair of articulated arms 20, 30 is uniquely determined, and the tweezers 50 is reliably driven in one of the longitudinal directions. So that there is no freedom of movement in other directions.

Therefore, as the drive system of the wafer handler, only the above-mentioned drive system is sufficient.
An additional drive system is provided to ensure 50 linear reciprocating drives. This is the third position above the rotation shaft 84.
And a fourth pulley 94 is fixed to the rotating shaft 92 of the connecting portion of the first and second arms 22 and 24.
3. A belt 96 is stretched between the fourth pulleys 90 and 94. The ratio between the diameters of the third pulley 90 and the fourth pulley 94 is 2: 1.

In addition, in order to prevent the diffusion of dust at the time of operation in the wafer handler having such an operation unit, the inside of the articulated arms 20 and 30 can be evacuated in this embodiment.

That is, as for one multi-joint arm 20, the first and second arms 22 and 24 have hollow shapes with internal cutouts as shown in FIG. 2,
Similarly, the rotating shafts 84, 92, 98 arranged at the third joints a, b, c are also hollow shafts, and the inside of the multi-joint arm 20 is in communication. Such a configuration is the same for the other articulated arms 30.

 Next, the operation will be described.

First, the wafer handler according to the present embodiment arranges the movement planes of the pair of articulated arms 20 and 30 so as to intersect each other, and adjusts the rotation axis 84 of the joint a of the first arm 22 in one of the articulated arms 20. It is rotated and driven by the motor 80. When the first arm 22 rotates at the first joint a by the drive of the motor 80, the movement positions of the other joints of the pair of articulated arms 20, 30 are uniquely determined,
As in the conventional flag leg method, it is necessary to adopt a complicated configuration in which both the pair of arms are synchronously rotated and the driving ratio is controlled while controlling the rotation ratio of the first and second arms to 2: 1. There is no.

Then, in the wafer handler of the present embodiment, as shown in FIG. 4, the tweezers 50 are moved to both the right and left sides of the position where the pair of articulated arms 20 and 30 are arranged. It is possible. That is, in the wafer handler of this embodiment, as shown in FIG. 2, the first and second arms 22, 24 and 32, 34 of the pair of articulated arms 20, 30 can completely overlap. Even when the tweezers 50 move in any of the left and right directions, there is no member that interferes with the movement of the tweezers 50 at all. Therefore, a large moving stroke of the tweezers 50 can be secured.

Here, when moving to both sides of the pair of articulated arms 20, 30, there is always a state where the arms overlap as shown in FIG. In this case, even if the first arm 22 is driven, the relative positions of the first and second arms 22 and 24 remain unchanged and do not change. There is a possibility that both arms 22 and 24 rotate around 84. This means that the other articulated arm
The same applies to 30. This phenomenon occurs when the tweezers and 50 move continuously due to their inertia.
Since the positions of the first and second arms 22 and 24 are shifted after the state shown in the figure, it is unlikely that this will actually occur. However, this measure is necessary because such a phenomenon may occur in the mechanism design. .

In this embodiment, the rotational force of the rotating shaft 84 at the first joint a is
The third and fourth pulleys 90 and 94 and the belt 96 are used to transmit the rotation to the rotation shaft 92 of the second joint b to rotate the second arm 24. The pair of articulated arms 20, 30
The second arm 24 needs to be rotationally driven under the restrained condition,
The diameter ratio of the third and fourth pulleys 90 and 94 is set to 2: 1.

Next, the operation of transferring the wafer 60 using the wafer handler will be described with reference to FIG.

In the figure, the tweezers 50 of this wafer handler are shown.
At one end of the moving path, a cassette 100 for accommodating, for example, 25 wafers 60 at a predetermined pitch in the vertical direction is provided, and at the other end, a processing apparatus 110 for performing wafer processing such as wafer etching and ashing is provided. Have been. Then, the wafer 60 taken out of the cassette 100 is supplied to the processing apparatus 110, and the processed wafer 60 is transferred to the cassette 100.
And a new process is performed by transferring a new wafer 60 from the cassette 100 to the processing device 110.

In such a case, first, as shown in FIG. 6A, one end of the tweezers 50 is inserted and moved into the cassette 100, and one wafer 60-1 is vacuum-sucked on the tweezers 50.

Next, the tweezers 50 are detached from the cassette 100 (see FIG. 6B), and in this state, the processing of the wafer 60-0 already loaded in the processing apparatus 110 is awaited.

When the processing in the processing device 110 is completed, the tweezers 50 is moved to the right from the state of FIG. 6B, and the processed wafer 60-0 is supported by the other vacuum suction unit 52 (FIG. 6C). )reference). Then, move the tweezers 50 to the left,
It stops at the position separated from the processing device 110 (see FIG. 6 (D)).

Thereafter, the base 70 is rotated by 180 °, and the tweezers 50 on the side supporting the wafer 60-1 are opposed to the processing apparatus 110, while the side supporting the processed wafer 60-0 is on the cassette 100. They are set to face each other (see FIG. 6 (E)).

Then, the tweezers 50 are moved to the left from the above state, and the new wafer 60-1 is delivered to the processing apparatus 110 (the sixth wafer).
FIG. (F).

Thereafter, the processing in the processing device 110 is started.
Utilizing this processing time, the processed wafer 60-0 is transported back to the cassette 100, and thereafter, the operation returns to FIG. 6A and the operation is repeated.

In this way, the double tweezers structure as described above, and if the base 70 is rotatable, it is possible to support a processed wafer while supporting a new wafer with the tweezers 50. If the base 70 is rotated in this state, the new wafer can be immediately transferred to the processing apparatus 110. Therefore, when there is only one suction unit, after receiving the processed wafer 60-0, it is returned to the cassette 100, and then a new wafer 60-1 is received from the cassette 100. In the above embodiment, the operation of moving the processed wafer 60-
After receiving 0 from the processing apparatus 110, the tweezers 50 can be rotated to immediately transfer the already held new wafer 60-1 to the processing apparatus 110, greatly improving the throughput of transferring the wafer. can do.

When a semiconductor wafer is to be transferred, this type of wafer handler is placed in a clean room,
In this embodiment, the arm and its connecting part have a hollow structure, and the inside of the arm is evacuated, so that the dust in the moving part can be prevented from spreading to the outside of the moving part. can do.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention.

The present invention relates to a pair of articulated arms 2 of a wafer handler.
By arranging 0,30 so that their moving planes intersect,
It is characterized by adopting a configuration in which the movement position of each joint is uniquely determined when a part of a pair of multi-joint arms is driven. Double tweezer structure, rotation structure of base 70, tweezers The configuration for moving to both sides of the joint arm or the like is not necessarily adopted.

[Effects of the Invention] As described above, according to the present invention, by arranging a pair of articulated arms such that their respective movement planes intersect, the degree of freedom in only the linear movement direction of the wafer support member is improved. It is possible to secure a wafer handler without adopting a complicated configuration, and to provide a wafer handler with a simpler configuration and lower cost than in the past.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of an embodiment of a wafer handler to which the present invention is applied. FIG. 2 is a schematic perspective view for explaining a neutral state in which the arms of the wafer handler of FIG. FIG. 3 is a schematic sectional view for explaining the internal structure of one articulated arm of the wafer handler shown in FIG. 1, and FIG. 4 is a schematic perspective view for explaining the movement of tweezers to both sides of the wafer handler. FIG. 5 is a schematic explanatory view schematically showing the most simplified mechanism when the moving planes of a pair of articulated arms intersect, and FIG. 6 is a wafer using the wafer handler of FIG. FIG. 7 is a schematic explanatory view for explaining a transfer operation, and FIG. 7 is a schematic explanatory view for explaining a conventional flag leg type wafer handler. 20, 30: a pair of articulated arms, 40: arm connecting member, 50: wafer support member (tweezers), 60: wafer, 70: base, 80: motor.

Claims (1)

(57) [Claims] A pair of multi-joint arms, each of which supports a wafer support member at one end thereof, and is arranged so as to intersect a moving plane of each of the pair of multi-joint arms; By rotating the other end of the arm,
A wafer handler, wherein the wafer support member is moved linearly.