JPH1133948A - Carrier robot and method for using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carrier robor and a method for using it, capable of easily handle samples such as wafer carriers arranged in the same direction (in parallel to each other). SOLUTION: A carrier robot is provided with a conveying arm 2, a first arm 4 and a second arm 5, and control of an R-axis is performed by combination control of the first arm 4 and the second arm 5. Control of the R-axis is performed by a controller 12 so that the center of an arm rotational driving shaft 3 may be moved on the straight line not passing the center of the axis of a θ shaft. The conveying arm 2 for conveying a wafer 1 is rotationally controlled by the arm rotational driving shaft 3 so as to be moved while always holding the attitude parallel to the straight line. Therefore, samples (wafers) placed on a plurality of parallel straight lines in the direction (in parallel to each other) can be easily handled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial transfer robot, and more particularly to a transfer robot used for transferring substrates such as wafers and reticles in the semiconductor industry.

[0002]

2. Description of the Related Art A conventional robot having an RθZ axis used for transporting a semiconductor wafer or the like has a shape as shown in FIGS. FIG. 8 shows a state where the R axis is extended.
FIG. 9 shows a state where the R axis is contracted. FIG. 10 shows a sectional view of each joint for R drive.

The wafer 1 is held on the transfer arm 51 by a method such as vacuum suction. The transfer arm 51 can move on the R axis while maintaining a posture parallel to the R direction by the first arm 52 for R driving, the first joint 52A, the second arm 53, and the second joint 53A. These R drive shafts are θ drive shafts 54.
, And the θ drive shaft 54 is supported by a Z drive shaft 55. Each drive shaft is controlled by the control unit 60.

The transfer arm 51 is configured to be able to move on the R axis while maintaining a posture parallel to the R direction.
In FIG. 10, a pulley 57A is provided in the first arm 52.
And a pulley 57B, and the two pulleys are connected by a belt 56A. Second arm 5
A pulley 57B and a pulley 57C are arranged in 3 and these two pulleys are connected by a belt 56B. The rotation ratio between the pulleys 57A and 57B and the rotation ratio between the pulleys 57C and 57B are both designed to be 2: 1. Also, the first arm 5
The length of the second arm 53 is equal to the length of the second arm 53. The transfer arm 51 is fixed to the pulley 57A.

With these configurations, when the R-axis drive is performed, the pulley 57C rotates as a drive shaft, and when the second arm 53 rotates by φ, the first arm 52 rotates in the opposite direction by 2φ with respect to the second arm 53. . As a result, the rotation axis of the pulley 57A moves on the R axis passing through the center of the θ axis. Then, the transfer arm 51 rotates in the direction opposite to the first arm by φ with respect to the first arm 52. Therefore, the posture of the transfer arm 51 can always be kept parallel to the R-axis direction. Accordingly, the rotation of the pulley 57C causes the transfer arm 51 to move on the R axis while maintaining a posture parallel to the R direction.

[0006]

The wafer 1 held on the transfer arm 51 is moved by the RθZ
Conveyed in each arbitrary direction of the shaft. However, with respect to the R axis, the transfer arm 51 must travel along a straight line passing through the center of the θ axis while maintaining a posture parallel to the straight line.

For this reason, as shown in FIG.
Must be arranged on a straight line passing through the center of the θ-axis such that the front surface thereof faces the center of the θ-axis. However, in the automation line, a special device is required to arrange the wafer carrier at such a position in the previous process.

When arranging a plurality of wafer carriers in the preceding process, it is easiest to arrange the wafer carriers in a straight line in the same direction (parallel to each other). However,
The conventional robot cannot handle the wafer carrier having such an arrangement, and in order to handle the wafer carrier, there is a problem that a driving device for further moving the conventional transfer robot in parallel is required.

The same is true for a conventional transfer robot using a straight guide 59 on the R axis as shown in FIG.

The present invention has been made in order to solve such problems, and a transfer robot capable of easily handling a sample such as a wafer carrier placed in the same direction (parallel to each other) and a method of using the same. The task is to provide

[0011]

A means for solving the above problem is a transfer robot provided with at least an R drive shaft and a θ drive shaft, which is installed at the tip of the R axis and has a θ rotation axis. A holding arm that holds the sample via a rotation drive shaft having a parallel rotation axis, and a plurality of parallel straight lines that do not pass through at least the center of the θ axis so that the holding arm advances while maintaining a posture parallel to the straight line. A transfer robot (Claim 1), further comprising a control unit for controlling the R drive shaft, the θ drive shaft, and the rotary drive shaft.

“The holding arm advances while maintaining a posture parallel to the plurality of parallel straight lines that do not pass through at least the θ-axis center” means that in addition to such a function, the function of the conventional robot is used. The purpose is not to exclude those having the same.

Further, as already described in the related art and as described below, the R drive shaft does not necessarily need to be composed of one drive shaft, and the operations of two or more drive shafts are combined. May also play the role of the R drive shaft.

In this transfer robot, the holding arm is controlled to advance on a plurality of parallel straight lines that do not pass through the center of the θ axis while maintaining a posture parallel to the straight line. Samples placed in the same direction (parallel to each other) can be easily handled.

Further, the method of using the transfer robot for solving the above-mentioned problem is such that a plurality of samples to be transferred are arranged in parallel on a plurality of parallel straight lines on which the holding arm advances, and the sample is transferred by the holding arm. A method of using the transfer robot according to claim 1 (claim 2).

According to this method, the sample can be arranged with a simple device in the previous step. That is, there is an advantage that an interface with an automatic wafer carrier transfer device such as a production line is facilitated.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1, 2 and 3 are diagrams showing an outline of a transfer robot which is an example of an embodiment of the present invention.
In the following drawings, the same components are denoted by the same reference numerals,
The description of those already described is omitted. 1 and 2 are perspective views of the transfer robot. FIG. 1 is a view showing a state where the R axis is extended, and FIG. 2 is a view showing a state where the R axis is contracted. FIG. 3 is a diagram showing the internal structure of the R axis.

The wafer 1 is held by a transfer arm (holding arm) 2 by means such as vacuum suction, and the transfer arm 2 is connected to an arm rotation drive shaft (rotation drive shaft) 3. Since the motor 3A is built in the arm rotation drive shaft 3, the transfer arm 2 is mounted on the arm rotation drive shaft 3.
Is configured to be rotatable around the rotation axis. The arm rotation drive shaft 3 is attached to the tip of the first arm 4,
The first arm 4 is configured to be pivotable about the first joint 4A. The first joint 4A is attached to the tip of the second arm 5, and the second arm 5
Is configured to be pivotable about the second joint 5A as a central axis.

As shown in FIG. 3, a pulley 8, a pulley 9, and a belt 10 are provided inside the second arm 5, and the pulley 8 is connected to the first arm 4 as a first joint 4A. The pulley 9 is driven by a motor 9A. That is, when the pulley 9 is rotated by the motor 9A, the first arm 4 is turned. Of course, instead of such a method, a motor may be directly connected to the first joint 4A to directly drive the first joint 4A.

Since the second arm 5 and the second joint 5A are mounted on a θ rotation drive shaft (θ drive shaft) 6, the second arm 5 is turned around the θ axis. Also, θ
The rotary drive shaft 6 is installed on a Z vertical drive shaft 7 and can move up and down. All these drive shafts are controlled by the control device 12.

The control of the θ-axis and the Z-axis is the same as that of the conventional method, and will not be described here. .

First, a control method when the transfer arm 2 is controlled to travel on an arbitrary straight line that does not pass through the center of the θ-axis while maintaining a posture parallel to this straight line will be described with reference to FIGS. explain.

In FIG. 4, when the transfer arm 2 runs on a straight line (X = d) separated by d from the θ-axis center while maintaining a posture parallel to the Y-axis, the relationship between R and θ is Rcos θ = d. . Assuming that the angle formed between the transfer arm 2 and the R axis is α, α is always a value obtained by adding π / 2 to θ, so that control is performed so as to always satisfy the two equations of Rcos θ = d α = θ + π / 2. Just do it.

When the angle α is defined by the angle formed by the transfer arm 1 and the first arm 4 and the lengths of the first arm 4 and the second arm 5 are both a, FIG. The control may be performed such that the following equation is satisfied at all times: Rcos θ = dα = θ + π / 2−cos ⁻¹ (R / (2a))

Next, control of the R axis will be described. The control of the R-axis is such that the second arm 5 is rotated by the θ-axis control, and the pulleys 9 and 8 are rotated by the motor 9A in relation to the amount of rotation so that the first arm 4 is connected to the second arm 5. Rotate with respect to. That is, the θ rotation drive shaft 6 is used for both independent control of the θ axis and control of the R axis. And such a first arm 4 and a second arm 5
As a result, the center of the arm rotation drive shaft 3 moves on a plurality of parallel straight lines that do not pass through the center of the θ axis.

The details of this control will be described with reference to FIG. When the X and Y axes are taken as shown in FIG. 5, control is performed so that the center of the arm rotation drive shaft 3 travels on a straight line (X = d) parallel to the Y axis which is separated from the Y axis by d. Consider. As shown in FIG. 5, the angle between the second arm 5 and the X axis is φ, the angle between the first arm 4 and the second arm 5 is ψ,
Assuming that the coordinates of the center of the arm rotation drive shaft 3 are (d, y), φ and ψ are determined such that d = a (cosφ−cos (φ + ψ)) y = a (sinφ−sin (φ + ψ)) Do it.

As shown in FIG. 6, two wafer carriers 11 for accommodating a plurality of wafers 1 are installed in parallel at a distance of 2d. The transfer arm 2 is controlled to move on a straight line separated by d from the center of the θ axis in parallel with the straight line, so that the wafer 1 is drawn straight out of the wafer carrier 11.

The present invention is not limited to this embodiment. For example, as shown in FIG. 7, a linear guide 13 may be used for the R axis.

Further, in the present embodiment, the two wafer carriers 11 are described in parallel, but the number of wafer carriers 11 is not limited to two. You can follow them.

[0030]

As described above, the transfer robot according to the present invention is a transfer robot having at least the R drive shaft and the θ drive shaft, and is provided at the tip of the R axis and is parallel to the θ rotation axis. A holding arm that holds the sample via a rotation drive shaft having a rotation axis of at least a plurality of parallel straight lines that do not pass through the center of the θ axis so that the holding arm advances while maintaining a posture parallel to this straight line. Since it has a control unit for controlling the R drive axis, the θ drive axis, and the rotary drive axis, it is possible to draw a wafer straight from a wafer carrier that is not directly facing the center direction of the transfer robot, and furthermore, this effect A plurality of wafer carriers can be set in parallel (in the same direction).

Therefore, there is an effect that an interface can be easily obtained as an apparatus with respect to an automatic transfer system of a wafer carrier in a production line or the like in a normal factory. Further, since a device for moving all the transfer robots in parallel with the conventional transfer robot for the wafer carrier placed in parallel is not required, it is also useful for cost reduction.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a transfer robot according to an embodiment of the present invention, and is a diagram illustrating a state where an R axis is extended.

FIG. 2 is a diagram illustrating an example of a transfer robot according to an embodiment of the present invention, and is a diagram illustrating a state in which an R axis is contracted.

FIG. 3 is a diagram illustrating an example of an internal structure of an R axis of the transfer robot illustrated in FIGS. 1 and 2;

FIG. 4 is a diagram illustrating a method for controlling a transfer robot according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating a control method of the transfer robot according to the embodiment of the present invention.

FIG. 6 is a diagram showing a positional relationship between a transfer robot and a wafer cassette according to an embodiment of the present invention.

FIG. 7 is a diagram showing another embodiment of the present invention.

FIG. 8 is a diagram illustrating a conventional transfer robot, and is a diagram illustrating a state where an R axis is extended.

FIG. 9 is a diagram illustrating a conventional transfer robot, and is a diagram illustrating a state where an R-axis is contracted.

FIG. 10 is a diagram showing the internal structure of the transfer robot shown in FIGS. 8 and 9;

FIG. 11 is a diagram illustrating a positional relationship between a conventional transfer robot and a wafer cassette.

FIG. 12 is a diagram showing another example of a conventional transfer robot.

[Explanation of symbols]

 1: Wafer 2: Transfer arm (holding arm) 3: Arm rotation drive axis (rotation drive axis) 4: First arm 4A: First joint 5: Second arm 5A: Second joint 6: θ rotation drive axis (θ 7) Z vertical drive shaft 12: Control device

Claims (2)

[Claims] 1. A transfer robot having at least an R drive shaft and a θ drive shaft, a holding device that is provided at a tip of the R axis and holds a sample via a rotary drive shaft having a rotation axis parallel to the θ rotation axis. An arm and a plurality of parallel straight lines that do not pass through at least the θ axis center while maintaining the posture parallel to the straight line and the R drive shaft so that the holding arm advances.
A transfer robot comprising: a control unit that controls a drive shaft and a rotary drive shaft. 2. The transport robot according to claim 1, wherein a plurality of samples to be transported are arranged in parallel on a plurality of parallel straight lines on which the holding arm advances, and the samples are transported by the holding arm. how to use.