Transport robot

Abstract

When transporting a workpiece from a source to a destination using a transport robot, it is possible to perform operations such as inspection on the workpiece while it is being transported, without actually increasing the transport time. [Solution] The transport robot comprises a hand 35 on which a workpiece W can be placed, an arm 30 to which the hand 35 is attached, which is equipped with one or more arm members 21, 22, and an additional device (electronic balance 24) for performing operations on the workpiece W. The additional device is provided, for example, on an arm support member 20 that supports the arm 30, and moves up and down on the arm support member 20 by a lifting mechanism 26 provided on the arm support member 20 that raises and lowers the additional device.

Description

Technical Field

[0001] The present invention relates to an industrial robot, and particularly to a transfer robot used for transferring works. Background Art

[0002] A transfer robot used for transferring works such as glass substrates and semiconductor substrates is configured by, for example, connecting a base, a hand on which a work is placed, and a plurality of arm members, so that it is extendable and retractable, and is composed of an arm with the hand connected to its tip, an arm support member that supports the arm, and an elevating mechanism that raises and lowers the arm support member relative to the base. Such a transfer robot is used, for example, to transfer a work between a plurality of processing apparatuses that perform various processes on the work. Patent Document 1 shows an example of such a transfer robot. The transfer robot described in Patent Document 1 further includes a cover member that covers the work during transfer, in order to transfer a work whose surface is wet with liquid.

[0003] There is a demand to inspect workpieces while they are being transported by a transport robot, or to change the orientation of workpieces on the handle. Traditionally, inspecting workpieces or changing their orientation required separate devices from the transport robot. In such cases, the workpiece was transported via these separate devices. For example, to measure the mass of a workpiece when transporting it from a source processing unit to a destination processing unit, a mass measuring device such as an electronic balance, separate from the transport robot, is used. The workpiece is transported from the source processing unit to the mass measuring device to measure its mass, and then transported from the mass measuring device to the destination processing unit. To change the orientation of a workpiece on the handle, a device called an aligner, equipped with a rotary table or similar, is used, and the workpiece is transported via this device. Devices that measure workpieces and aligners that change the orientation of workpieces will be collectively referred to as additional devices. However, transporting workpieces via an additional device separate from the transport robot requires time for processing the workpieces in the additional device, and also increases the actual time the robot is moving for transport due to the longer transport path. As a result, the effective transport time from the source processing device to the destination processing device increases, worsening the throughput of workpiece transport via the transport robot.

[0004] Patent Document 2 discloses a vertical articulated robot equipped with a gripper for gripping a workpiece, wherein a weight measuring sensor is provided in the wrist mechanism to measure the mass of the workpiece being gripped by the gripper. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2021-27210 [Patent Document 2] Japanese Patent Application Publication No. 6-31667 [Overview of the project] [Problems that the invention aims to solve]

[0006] The robot described in Patent Document 2 can measure the mass of a workpiece, but because it needs to grip the workpiece, it is not suitable for transporting workpieces that should not be gripped, such as semiconductor wafers or glass substrates for liquid crystal displays. Furthermore, since the mass measured by the weight measurement sensor includes the mass of the gripper, it is difficult to improve the accuracy of measuring the mass of the workpiece itself.

[0007] The object of the present invention is to provide a transport robot that can perform operations such as inspection on a workpiece while the workpiece is being transported, without significantly increasing the actual transport time. [Means for solving the problem]

[0008] According to one embodiment, a transport robot used for transporting workpieces comprises a hand on which a workpiece can be placed, an arm to which the hand is attached and which has one or more arm members, and an additional device for performing operations on the workpiece. [Effects of the Invention]

[0009] According to the present invention, it becomes possible to perform operations such as inspection on a workpiece while it is being transported, without significantly increasing the actual transport time. [Brief explanation of the drawing]

[0010] [Figure 1] Figures 1(a) and 1(b) are a perspective view and a side view, respectively, showing one embodiment of a transport robot. [Figure 2] Figures 2(a) and 2(b) are front and rear views, respectively, of the transport robot. [Figure 3] Figures 3(a), 3B(b), and 3(c) are a plan view, a front view, and a side view, respectively, showing the configuration of the main parts of the transport robot. [Figure 4]Figures 4(a) and 4(b) are a plan view and a side view, respectively, showing the configuration of the main parts of the transport robot with its arm extended. [Figure 5] Figures 5(a) and 5(b) are a front view and a side view, respectively, showing the configuration of the main components of a transport robot used to measure the mass of a workpiece. [Modes for carrying out the invention]

[0011] Next, embodiments of the present invention will be described with reference to the drawings. Figure 1(a) is a perspective view showing one embodiment of a transport robot, and Figure 1(b) is a side view of the transport robot. Figures 2(a) and 2(b) are a front view and a rear view of the transport robot, respectively.

[0012] The illustrated transport robot is used to transport a plate-shaped workpiece W, such as a semiconductor wafer or a glass substrate, from the discharging processing unit to the loading processing unit, while holding the workpiece W horizontally. It is similar to the transport robot described in Patent Document 2, except that it is equipped with an electronic balance 24, which will be described later.

[0013] The transport robot is equipped with a base 11, and a turntable 12 is provided on the upper surface of the base 11. The turntable 12 is rotatable around a rotation axis that extends vertically through the center of the base 11, and the turntable 12 is rotationally driven by a motor (not shown) that constitutes the rotation mechanism. The turntable 12 is provided with a pair of support columns 13 and 14 that extend upward perpendicular to the horizontal plane, and the upper ends of the support columns 13 and 14 are connected to each other via a top plate member 15. The support columns 13 and 14 and the top plate member 15 constitute a gate-shaped frame.

[0014] The workpiece W is placed on the hand 33 and transported. As will be described later, the hand 33 is attached to the arm 30, and the arm 30 is supported by the arm support member 20. The arm support member 20 is a hollow, elongated block-shaped structure provided in a direction perpendicular to the opening surface of the gate-type frame, that is, in the direction indicated by arrow L in the figure. A slider 21 is attached to the arm support member 20. On the back surfaces of the support columns 13 and 14, grooves 16 and 17 are formed, respectively, extending from the lower end to the upper end of the support columns 13 and 14, and ball screws (not shown) are provided inside each of the grooves 16 and 17. The slider 21 is provided to extend horizontally and further extends into the grooves 16 and 17 of the support columns 13 and 14, connecting to the ball screws inside the grooves 16 and 17. By rotating the ball screws inside grooves 16 and 17, the slider 21 moves up and down along the surface of the support columns 13 and 14, and as a result, the arm support member 20 also moves up and down. The ball screws inside the support columns 13 and 14 and the slider 21 constitute a lifting mechanism for raising and lowering the arm support member 20. Here, the slider 21 is moved up and down by the ball screws to raise and lower the arm support member 20, but instead of ball screws, a belt may be provided inside the support columns 13 and 14, and the lifting mechanism for the arm support member 20 may be configured by the belt and the slider 21. In Figure 1(b), the arm support member 20 is depicted in two locations, but the lower arm support member 20 shown represents the arm support member 20 at the lowest position within the liftable range of the arm support member 20, and the upper arm support member 20 shown represents the arm support member 20 at the highest position within the liftable range of the arm support member 20.

[0015] The hand 33 consists of a base portion 34 which connects to the arm 30, and a mounting portion 35 which is located at the tip of the hand 33 and is the part on which the workpiece W is actually placed. In the illustrated example, assuming that the workpiece W is a disc-shaped semiconductor wafer, the mounting portion 35 is formed in a fork shape with a bifurcated tip.

[0016] To prevent liquids or other substances on the surface of the workpiece W from spilling and scattering around the transport robot during transport, the transport robot of this embodiment, like the transport robot described in Patent Document 2, is equipped with a pair of protective covers 22 and 23. One protective cover 22 is fixed to the arm support member 20, and the other protective cover 23 is configured to move in accordance with the movement of the hand 33. The configuration of the protective covers 22 and 23 and the mechanism for driving the protective cover 23 are the same as those described in Patent Document 2, so a detailed description of them is omitted.

[0017] Figures 3(a), 3(b), and 3(c) all show the arm support member 20, arm 30, and hand 33 as key components of a transport robot. Figure 3(a) is a plan view showing the arm support member 20, arm 30, and hand 33 as a cross-sectional view along line AA in Figure 2(b). Figure 3(b) is a front view of the arm support member 20 showing its internal structure. Figure 3(c) is a side view of the arm support member 20 showing its internal structure. Figure 3(a) is drawn as a perspective view of the top surfaces of the protective covers 22 and 23. In Figure 3(b), the slider 21 is not shown for clarity of explanation.

[0018] The arm 30 is formed by connecting a first arm member 31 and a second arm member 32. One end of the first arm member 31 is attached to the arm support member 20 so that the first arm member 31 can rotate in a horizontal plane. One end of the second arm member 32 is attached to the other end of the first arm member 31 so that the second arm member 32 can rotate in a horizontal plane. The hand 33 has its base portion 34 attached to the other end of the second arm member 32 so that the hand 33 can rotate in a horizontal plane. A motor 36 that rotationally drives the first arm member 31 relative to the arm support member 20 is also attached to the arm support member 20. In practice, a link mechanism is provided inside the first arm member 31 and the second arm member 32 such that by rotationally driving the motor 36, the hand 33 performs linear motion in the L direction without changing its orientation. In this case, the arm 30 extends and contracts along the L direction as the motor 36 rotates. When the arm 30 is in the extended state (i.e., the first state), the hand 33 is at a position advanced horizontally from the position on the arm support member 20. When receiving or transferring the workpiece W to or from the processing apparatus, the arm 30 is set to the extended state to allow the hand 33 to enter the processing apparatus. On the other hand, when the arm 30 is in the contracted state (i.e., the second state), the hand 33 is positioned completely above the arm support member 20. The arm 30 extends and contracts by transitioning between the first state and the second state. When the arm 30 is in the contracted state, the turntable 12 can be rotated around the base 11 and the arm support member 20 can be raised and lowered without interfering with the processing apparatus or other objects. In addition to driving the arm 30, the motor 36 also moves the protective cover 23 in accordance with the extension and contraction of the arm 30. FIGS. 3(a), 3(b) and 3(c) show the state where the arm 30 is contracted. In FIGS. 3(a) and 3(c), the contour of the protective cover 23 when the arm 30 is extended is indicated by reference sign B. FIG. 4(a) is a plan view similar to FIG. 3(a), and FIG. 4(b) is a side view similar to FIG. 3(c), while FIGS. 4(a) and 4(c) show the state where the arm 30 is extended.

[0019] When transporting a workpiece W using the transport robot of this embodiment, first, with the arm 30 retracted, the turntable 12 is rotated to raise and lower the arm support member 20 so that it faces the entrance / exit of the transport source processing device. Then, the arm 30 is extended to allow the hand 33 to enter the entrance / exit of the transport source, and the workpiece W is placed on the mounting part 35 of the hand 33. This operation is called the Get operation. Next, with the workpiece W still being held, the arm 30 is retracted, and the turntable 12 is rotated to raise and lower the arm support member 20 so that it faces the entrance / exit of the transport destination processing device. Then, the arm 30 is extended to allow the hand 33 to enter the entrance / exit of the transport destination, and the workpiece W on the mounting part 35 of the hand 33 is unloaded into the processing device. This operation is called the Put operation. In the process of transporting the workpiece W from the transport source processing device to the transport destination processing device, the arm 30 is always retracted. In the workpiece transfer device of this embodiment, an additional device for performing some operation on the workpiece W is attached to the transfer robot, and the additional device performs the operation on the workpiece W when the arm 30 is retracted for transfer. Examples of operations on the workpiece W include measuring the mass of the workpiece W or changing the orientation of the workpiece W. In the following description, the case in which the mass of the workpiece W is measured will be described as an operation on the workpiece W.

[0020] The arm support member 20 is equipped with an electronic balance 24 for measuring mass and a lifting mechanism 26 for raising and lowering the electronic balance 24 on the arm support member 20. The lifting mechanism 26 comprises a main body fixed to the arm support member 20 and a lifting platform 27 that moves up and down relative to the main body, with the electronic balance 24 mounted on the lifting platform 27. Inside the electronic balance 24 is a weighing section (not shown) composed of a load cell or electromagnetic coil, and a detection section 25 mechanically connected to the weighing section protrudes from the upper surface of the electronic balance 24. The electronic balance 24 is configured to measure the mass of an object placed on the detection section 25. The electronic balance 24 is positioned inside the arm support member 20 such that the detection section 25 is located directly below the center of the workpiece W placed on the hand 33 when the arm 30 is retracted. Normally, the electronic balance 24 is in a lowered position within the arm support member 20 by the lifting mechanism 26, as shown in Figures 3(b) and 3(c). In this state, the electronic balance 24 and its sensing unit 25 do not interfere with the extension and retraction of the arm 30 or the movement of the hand 33. When measuring the mass of the workpiece W, the lifting mechanism 26 raises the electronic balance 24 within the arm support member 20 so that the sensing unit 25 contacts the lower surface of the workpiece W. Once the sensing unit 25 makes contact and the workpiece W is slightly lifted from the hand 33, the lifting mechanism 26 is stopped in that position so that the entire mass of the workpiece W acts on the sensing unit 25. As a result, the weighing unit inside the electronic balance 24 can measure the mass of the workpiece W via the sensing unit 25. After the mass measurement is complete, the electronic balance 24 is lowered again by the lifting mechanism 26. In the illustrated example, the mounting section 35 of the hand 33 is branched into two, and two forks 35A and 35B are provided. Therefore, there are no forks directly above the detection unit 25. Consequently, the detection unit 25 can be brought into contact with the lower surface of the workpiece W without interfering with the hand 33.

[0021] In mass measurement, vibrations cause noise and errors, so it is preferable that the transfer robot remains stationary while the mass of the workpiece W is being measured by the electronic balance 24. That is, it is preferable that the rotation by the rotary table 12 and the elevating motion of the arm support member 20 are stopped. However, if the influence of vibrations generated in the transfer robot can be ignored, the mass of the workpiece W can be measured even while the rotation by the rotary table 12 or the elevating motion of the arm support member 20 for transferring the workpiece W is being performed. When an additional device separate from the robot is provided to measure the mass of the workpiece W, time is required to transfer the workpiece W from the transfer-source processing device to the additional device, for the measurement in the additional device, and to transfer the workpiece W from the additional device to the transfer-destination processing device. In contrast, in the case of the present embodiment, although the time required for measurement by the electronic balance 24 corresponding to the additional device is necessary, the workpiece W only needs to be directly transferred from the transfer-source processing device to the transfer-destination processing device, so the overall required time can be reduced compared with the case where an additional device is provided separately from the robot. If the robot may actually be in motion during the mass measurement by the electronic balance 24, the overall required time can be further shortened according to the present embodiment. In addition, since the arm support member 20 is provided with the protective covers 22 and 23, the mass of the workpiece W can be measured without being affected by air currents or the like.

[0022] In the above description, the case in which the additional device provided on the arm support member 20 for operating on the workpiece W during transport is an electronic balance 24 was explained, but the additional device may be a device other than the electronic balance 24. For example, an aligner that rotates the workpiece W, which is placed horizontally on the hand 33, to change the orientation of the workpiece W in the horizontal plane can be provided as an additional device. When providing an aligner as an additional device, the aligner should be attached to the lifting mechanism 26 so that the rotation axis of the aligner protrudes from the body of the aligner, similar to the detection unit 25 in the electronic balance 24. When changing the orientation of the workpiece W, the aligner should be raised so that the rotation axis contacts the lower surface of the workpiece W and the workpiece W is slightly lifted from the hand 33, and then the rotation axis should be rotated in that state to change the orientation of the workpiece W to the desired orientation. After that, the aligner will be lowered again.

[0023] According to the transport robot of this embodiment described above, it is possible to measure the mass of the workpiece W or change its orientation while the workpiece W is being transported, without substantially increasing the time required to transport the workpiece W from the source to the destination, while keeping the workpiece W horizontal.

[0024] The above describes an example of a configuration for carrying out the present invention, but the above technology can take the following configuration.

[0025] [1] A transport robot used for transporting workpieces, A hand on which a workpiece can be placed, An arm to which the hand is attached, comprising one or more arm members, An additional device for performing operations on the workpiece, A transport robot equipped with [a specific feature / ability].

[0026] According to the configuration in [1], since the auxiliary device that performs actions on the workpiece is provided on the transport robot itself, the time required to move the workpiece to the auxiliary device can be reduced compared to the case where the auxiliary device is provided independently of the robot.

[0027] [2] An arm support member that supports the arm, A first lifting mechanism provided on the arm support member for raising and lowering the additional device, A transport robot according to [1], having the following:

[0028] [3] The arms are connected to each other and are configured by connecting a plurality of arm members so that each of the arm members can rotate in the horizontal plane, The hand is connected to the arm member at the tip of the arm so as to be rotatable in a horizontal plane. The transport robot according to [2], wherein the additional device rises when the operation is performed on the workpiece, and lowers when the operation is completed.

[0029] [4] The transport robot according to [3], wherein the arm is extendable, and in a first state in which the arm is extended, the hand is positioned horizontally forward from its position on the arm support member, and in a second state in which the arm is retracted, the hand is positioned on the arm support member such that the workpiece placed on the hand is directly above the additional device.

[0030] According to the configuration of [2], by providing an additional device on the arm support member that supports the arm and enabling the additional device to move up and down, the configuration of the transport robot can be simplified and interference of the additional device with the movement of the arm can be prevented. In particular, according to the configuration of [3], interference of the additional device with the movement of the arm can be prevented when there is a horizontal multi-joint arm, and according to the configuration of [4], when the arm is in the second state and the hand is on the arm support member, operations on the workpiece can be performed by the additional device. If the second state inevitably occurs during the transport of the workpiece, operations on the workpiece can be performed by the additional device at that time, so operations on the workpiece can be performed without actually increasing the transport time.

[0031] [5] The transport robot according to [4], wherein the additional device is an electronic balance with a protruding detection unit for detecting mass, and when raised by the first lifting mechanism, the detection unit contacts the lower surface of the workpiece to measure the mass of the workpiece.

[0032] [6] The transfer robot according to [4], wherein the additional device is an aligner with an exposed rotating shaft, the end of the rotating shaft contacts the lower surface of the workpiece when raised by the first lifting mechanism, and the orientation of the workpiece is changed by rotating the rotating shaft while the end of the rotating shaft is in contact with the lower surface of the workpiece.

[0033] According to the configuration in [5], it is possible to measure the mass of the workpiece while it is being transported, and according to the configuration in [6], it is possible to change the orientation of the workpiece while it is being transported.

[0034] [7] Base and, A rotating platform that can rotate around an axis perpendicular to the base, A rotation mechanism for rotating the turntable relative to the base, A frame attached to the rotating base and holding the arm support member so that it can be raised and lowered, A second lifting mechanism for raising and lowering the arm member relative to the frame, Furthermore, The conveying robot according to any one of [4] to [6], wherein the rotation mechanism and the second lifting mechanism operate when the arm is in the second state.

[0035] According to the configuration of [7], when transporting workpieces between multiple processing units arranged to surround the space in which the transport robot is located, it becomes possible to perform operations on the workpieces by an additional device while the workpieces are being transported, while preventing the transport robot from interfering with surrounding objects and preventing the transport time from being substantially prolonged. [Explanation of Symbols]

[0036] 11...Base; 12...Rotating platform; 13,14...Support column; 15...Top plate member; 16...Groove; 20...Arm support member; 21...Slider; 22,23...Protective cover; 24...Electronic balance; 25...Detection unit; 26...Lifting mechanism; 27...Lifting platform; 30...Arm; 31,32...Arm member; 33...Hand; 34...Base; 35...Mounting unit; 35A,35B...Fork; 36...Motor; W...Workpiece.

Claims

1. A transport robot used for transporting workpieces, A hand on which a workpiece can be placed, An arm to which the hand is attached, comprising one or more arm members, An additional device for performing operations on the workpiece, A transport robot equipped with [a specific feature / ability].

2. An arm support member that supports the aforementioned arm, A first lifting mechanism provided on the arm support member for raising and lowering the additional device, A transport robot according to claim 1, having the following features.

3. The arms are interconnected and configured by connecting multiple arm members so that each of the arm members can rotate in a horizontal plane. The hand is connected to the arm member at the tip of the arm so as to be rotatable in a horizontal plane. The transport robot according to claim 2, wherein the additional device rises when the operation is performed on the workpiece, and lowers when the operation is completed.

4. The transport robot according to claim 3, wherein the arm is extendable, and in a first state where the arm is extended, the hand is positioned horizontally forward from its position on the arm support member, and in a second state where the arm is retracted, the hand is positioned on the arm support member such that the workpiece placed on the hand is directly above the additional device.

5. The transport robot according to claim 4, wherein the additional device is an electronic balance with a protruding detection unit for detecting mass, and when raised by the first lifting mechanism, the detection unit contacts the lower surface of the workpiece to measure the mass of the workpiece.

6. The transport robot according to claim 4, wherein the additional device is an aligner with an exposed rotating shaft, and when raised by the first lifting mechanism, the end of the rotating shaft contacts the lower surface of the workpiece, and the orientation of the workpiece is changed by rotating the rotating shaft while the end of the rotating shaft is in contact with the lower surface of the workpiece.

7. Base and, A rotating platform that can rotate around an axis perpendicular to the base, A rotation mechanism for rotating the turntable relative to the base, A frame attached to the rotating base and holding the arm support member so that it can be raised and lowered, A second lifting mechanism for raising and lowering the arm member relative to the frame, Furthermore, The conveying robot according to any one of claims 4 to 6, wherein the rotation mechanism and the second lifting mechanism operate when the arm is in the second state.

Images