Substrate Transport Robot

Abstract

To provide a useful configuration that can hold and transfer a substrate in a substrate transfer robot.SOLUTION: A substrate transfer robot that transfers a substrate includes a hand unit. The hand unit includes a hand body and a tactile sensor. The sensing surface of the tactile sensor is arranged above the hand body. The hand unit supports the lower surface of the substrate from below at three or more locations, and the tactile sensor is arranged at at least one of the locations.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a robot for transporting a substrate. [Background technology]

[0002] Conventionally, robots have been used to transport semiconductor substrates, etc. Patent Document 1 discloses this type of substrate transport robot.

[0003] In the substrate transport robot of Patent Document 1, a suction head is formed at the tip of the end effector. This suction head is connected to a suction pipe inside the end effector. Therefore, the substrate can be sucked and held at the tip position of the end effector. A contact sensor that detects the substrate holding state is built in near the suction head. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-170382 A Summary of the Invention [Problem to be solved by the invention]

[0005] The configuration of suctioning a substrate as in Patent Document 1 has limitations, such as the inability to be applied to a vacuum environment, etc. Therefore, a different configuration for transporting a substrate by hand has been required.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a useful configuration for a substrate transport robot that is capable of holding and transporting a substrate. [Means for solving the problem]

[0007] The problem to be solved by the present invention has been described above. Next, the means for solving this problem and the effects thereof will be described.

[0008] The present invention One According to one aspect, there is provided a substrate transport robot having the following configuration. That is, this substrate transport robot transports a substrate. The substrate transport robot includes a hand unit. The hand unit includes a hand body and a tactile sensor. A sensing surface of the tactile sensor is disposed above the hand body. The hand unit supports the bottom surface of the substrate from below at three or more points, and the tactile sensor is disposed at at least one of the points. The tactile sensor is capable of detecting an externally applied force in three axial directions.

[0009] This makes it possible to obtain various information about the board placed on the hand unit with a simple configuration, making it easy to grasp the situation occurring on the board in three dimensions. Effect of the Invention

[0010] According to the present invention, it is possible to provide a useful configuration for a substrate transport robot that is capable of holding and transporting a substrate. [Brief description of the drawings]

[0011] [Figure 1] 1 is a perspective view showing an overall configuration of a robot according to an embodiment of the present invention; [Diagram 2] FIG. 4 is an enlarged perspective view showing in detail a tactile sensor disposed in the hand unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Next, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing the overall configuration of a robot 100 according to an embodiment of the present invention.

[0013] The robot 100 shown in Fig. 1 is installed, for example, in a manufacturing factory for substrates W such as semiconductor wafers. The robot 100 is used to transport the substrate W between a plurality of positions. The substrate W may be any of a substrate raw material, a semi-finished product being processed, and a processed finished product. The shape of the substrate W is a disk in this embodiment, but is not limited thereto.

[0014] The robot 100 is configured as a substrate transport robot. More specifically, the robot 100 is a vacuum robot used in a space sealed against the external environment. The inside of the space is filled with a predetermined gas. This gas may be, for example, nitrogen gas. Since the amount of gas filled is considerably small, the inside of the space is substantially in a vacuum state.

[0015] The robot 100 mainly comprises a base 1, a robot arm (arm portion) 2, a robot hand (hand portion) 3, and a controller 9.

[0016] The base 1 is fixed to the floor surface of a vacuum chamber or the like. However, the present invention is not limited to this, and the base 1 may be fixed to, for example, an appropriate processing facility.

[0017] 1, the robot arm 2 is attached to the base 1 via a lift shaft 11 that is vertically movable. The robot arm 2 is rotatable about the lift shaft 11.

[0018] The robot arm 2 is a horizontally articulated robot arm. The robot arm 2 includes a first arm 21 and a second arm 22.

[0019] The first arm 21 is configured as a long and thin member extending horizontally and linearly. One end of the first arm 21 in the longitudinal direction is attached to the upper end of the lifting shaft 11. The first arm 21 is supported so as to be rotatable about the axis (vertical axis) of the lifting shaft 11. The second arm 22 is attached to the other end of the first arm 21 in the longitudinal direction.

[0020] The second arm 22 is configured as a long and thin member extending horizontally and linearly. One end of the second arm 22 in the longitudinal direction is attached to the tip of the first arm 21. The second arm 22 is supported so as to be rotatable about an axis (vertical axis) parallel to the lift shaft 11. The robot hand 3 is attached to the other end of the second arm 22 in the longitudinal direction.

[0021] The lift shaft 11, the first arm 21 and the second arm 22 are each driven by a suitable actuator (not shown). This actuator may be, for example, an electric motor.

[0022] Encoders (not shown) that detect the rotational positions of the first arm 21, the second arm 22, and the robot hand 3 are attached to the arm joints located between the lifting shaft 11 and the first arm 21, between the first arm 21 and the second arm 22, and between the second arm 22 and the robot hand 3. In addition, an encoder that detects a change in position of the first arm 21 in the height direction (i.e., the amount of lift of the lifting shaft 11) is also provided at an appropriate position on the robot 100.

[0023] The controller 9 controls the operation of the electric motors that drive the lift shaft 11, the first arm 21, the second arm 22, and the robot hand 3. These electric motors are controlled based on position information including the rotational position or height position of the first arm 21, the second arm 22, or the robot hand 3 detected by each encoder.

[0024] The robot hand 3 is configured as a so-called passive grip type. The robot hand 3 includes a wrist portion 31 and a hand body portion 32, as shown in FIG.

[0025] The wrist 31 is attached to the tip of the second arm 22. The wrist 31 is supported so as to be rotatable about an axis (vertical axis) parallel to the lift shaft 11. The wrist 31 is rotationally driven by an appropriate actuator (not shown). This actuator may be, for example, an electric motor. A hand main body 32 is connected to the wrist 31. The wrist 31 and the hand main body 32 may be formed integrally.

[0026] The hand main body 32 is a portion on which the substrate W is placed. The hand main body 32 is composed of a plate-like member formed in a Y shape (or a U shape). The hand main body 32 is shaped so that the side connected to the wrist 31 and the opposite side (in other words, the tip side) are bifurcated.

[0027] The hand main body 32 is provided with a plurality (three) of tactile sensors 6a, 6b, 6c for contacting and supporting the underside of the substrate W. Two tactile sensors 6a, 6b are arranged on the tip side of the hand main body 32. The hand main body 32 is formed so that the tip side branches into two. The tactile sensor 6a is provided on one branched portion, and the tactile sensor 6b is provided on the other branched portion. One tactile sensor 6c is provided on the base end side of the hand main body 32.

[0028] The three tactile sensors 6a, 6b, and 6c contact the underside of the substrate W placed on the robot hand 3 near its peripheral edge to hold the substrate W. The tactile sensors 6a, 6b, and 6c contact the underside of the substrate W to support the substrate W from below. The substrate W is held parallel to the robot hand 3 and does not shift due to static friction generated in the portions in contact with the tactile sensors 6a, 6b, and 6c.

[0029] Since the three tactile sensors 6a, 6b, and 6c all have the same configuration, the configuration of the tactile sensor 6a will be described below as a representative example.

[0030] The tactile sensor 6 a includes a sensor element 61 , a sensor substrate 62 , and a signal cable 63 .

[0031] The sensor element 61 has a sensing surface capable of directly contacting the lower surface of the substrate W. The sensing surface is disposed at the upper end of the sensor element 61. The sensor element 61 can detect the force applied from the substrate W in three axial directions (X-axis direction, Y-axis direction, and Z-axis direction described below). The sensor element 61 is disposed so as to be convex upward relative to the hand main body 32. The sensor element 61 may have any configuration, but may, for example, be configured such that piezoresistors are disposed in the above-mentioned three axial directions.

[0032] The sensor substrate 62 is formed in a small plate shape, and is disposed below the sensor element 61. A conductive pattern is formed on the sensor substrate 62, and this conductive pattern is electrically connected to a terminal that the sensor element 61 has.

[0033] The signal cable 63 is configured as, for example, a flexible flat cable. One end of the signal cable 63 is electrically connected to the sensor board 62. The other end of the signal cable 63 is connected to the controller 9. This allows the controller 9 to communicate with the sensor board 62 in an appropriate manner and obtain the detection value of the tactile sensor 6a. The communication method may be, for example, known serial communication, but is not limited to this. The signal cable 63 is arranged to pass through the hand main body 32.

[0034] The tactile sensor 6a is configured as a three-axis type tactile sensor that can detect the magnitude of an externally applied force in the X-axis direction, which is the width direction of the hand, the Y-axis direction, which is the central axis direction of the hand, and the Z-axis direction, which is the thickness direction of the hand.

[0035] The above-mentioned tactile sensors 6a, 6b, and 6c have various applications, as exemplified below.

[0036] (1) When the substrate W is placed on the tactile sensors 6a, 6b, and 6c, the tactile sensors 6a, 6b, and 6c detect a force in the Z-axis direction. Therefore, based on the output of the tactile sensors 6a, 6b, and 6c, it is possible to detect whether the substrate W is placed on the robot hand 3. This configuration is suitable, for example, when automatically teaching the robot 100 the transport position in the Z-axis direction of the substrate W.

[0037] (2) If the Z-axis directions of the tactile sensors 6a, 6b, and 6c are completely vertical, only the detection values ​​of the tactile sensors 6a, 6b, and 6c change in the Z-axis direction when the substrate W is placed on the tactile sensors. However, if the Z-axis directions of the tactile sensors 6a, 6b, and 6c are inclined relative to the vertical, the detection values ​​in the X-axis direction or the Y-axis direction also change depending on the degree of the angular deviation in the Z-axis direction when the substrate W is placed on the tactile sensors. Therefore, the inclination of the hand main body 32 can be obtained based on the output of the tactile sensors 6a, 6b, and 6c. Similarly, the phenomenon in which the tip of the robot hand 3 droops due to aging can also be detected based on the output of the tactile sensors 6a, 6b, and 6c.

[0038] (3) When the substrate W is placed on the robot hand 3, but the center of the substrate W is misaligned with respect to the center of the hand main body 32, the position of the center of gravity of the substrate W differs from normal, and the magnitude of the force in the Z-axis direction applied to each of the tactile sensors 6a, 6b, 6c differs. When the semiconductor wafer is supported at three points by the tactile sensors 6a, 6b, 6c, the position of the wafer shifts, and the direction and magnitude of the position shift can be detected by using the direction and amount of change in the detection values ​​of each of the tactile sensors 6a, 6b, 6c and the balance of the detection values ​​at the three points.

[0039] (4) Depending on the process performed on the substrate W, the surface of the substrate W may be sticky. When the substrate W at a predetermined position is taken out by the robot hand 3, the substrate W may tend to stay at the position as if it was stuck to the position. As a result, during the process of taking out the substrate W by the robot hand 3, slippage occurs between the substrate W and the robot hand 3, and the position of the substrate W relative to the robot hand 3 is displaced. Even if the surface of the substrate W is not sticky, the position of the substrate W relative to the robot hand 3 may be displaced due to the action of inertia force or the like. It is considered that the detection values ​​of the tactile sensors 6a, 6b, and 6c show some special behavior not only at the moment when the substrate W is displaced, but also immediately before the displacement occurs. The controller 9 monitors the detection values ​​of the tactile sensors 6a, 6b, and 6c in real time, and immediately performs control such as deceleration when the above behavior is detected, thereby preventing the substrate W from being displaced.

[0040] In this embodiment, two tactile sensors 6a, 6b are disposed at the tip of the hand main body 32, and one tactile sensor 6c is disposed at the base of the hand main body 32. Therefore, it is possible to appropriately respond to the difference in the way vibrations are generated on the tip side and the base side of the hand, and to detect in advance the situation that may lead to the occurrence of positional deviation.

[0041] (5) When the substrate W is placed on the robot hand 3, a force corresponding to the acceleration of the substrate W is applied to the tactile sensors 6a, 6b, and 6c. Therefore, the tactile sensors 6a, 6b, and 6c can also be used to measure acceleration.

[0042] (6) When the substrate W is placed on the robot hand 3, if the substrate W or the robot hand 3 collides with the external environment, the tactile sensors 6a, 6b, and 6c detect a large force. Therefore, the tactile sensors 6a, 6b, and 6c can also be used for collision detection.

[0043] As described above, the robot 100 of this embodiment transports the substrate W. The robot 100 includes the robot hand 3. The robot hand 3 includes a hand main body 32 and tactile sensors 6a, 6b, and 6c. The robot hand 3 supports the lower surface of the substrate W from below at three locations, and the tactile sensors 6a, 6b, and 6c are disposed at all of these locations.

[0044] This makes it possible to obtain various pieces of information relating to the substrate W placed on the robot hand 3 with a simple configuration.

[0045] In the substrate transport robot of this embodiment, the robot hand 3 is a passive grip type hand.

[0046] In the case of the passive grip type, the wafer is prone to misalignment with respect to the robot hand 3. According to the above configuration, information regarding the behavior of the wafer with respect to the robot hand 3 can be appropriately acquired by the tactile sensors 6a, 6b, and 6c.

[0047] In the robot 100 of this embodiment, the tactile sensors 6a, 6b, and 6c are disposed at all the locations where the lower surface of the substrate W is supported.

[0048] This makes it possible to detect the condition occurring on the substrate W with high accuracy.

[0049] Furthermore, in the robot 100 of this embodiment, the tip of the robot hand 3 is branched, and tactile sensors 6a and 6b are disposed at each of the branched portions.

[0050] This allows the tactile sensors 6a, 6b to stably support the substrate W while obtaining information about the substrate W through the tactile sensors 6a, 6b.

[0051] In the robot 100 of this embodiment, two tactile sensors 6a and 6b are disposed on the tip side of the robot hand 3, and one tactile sensor 6c is disposed on the base side of the robot hand 3.

[0052] This makes it possible to appropriately acquire information regarding vibration conditions and the like that differ between the tip side and the base side of the robot hand 3.

[0053] Furthermore, in the robot 100 of this embodiment, the tactile sensors 6a, 6b, and 6c are capable of detecting forces applied from the outside in three axial directions.

[0054] This makes it easier to grasp the situation occurring on the substrate W in three dimensions.

[0055] Although the preferred embodiment of the present invention has been described above, the above configuration can be modified, for example, as follows.

[0056] When the substrate W is a semiconductor wafer, it is preferable that the tactile sensors 6a, 6b, and 6c that come into contact with the substrate W are electrically connected to the robot arm 2. This connection can be achieved, for example, by using a signal cable 63. By electrically connecting the tactile sensors 6a, 6b, and 6c that come into contact with the substrate W to the robot arm 2, static electricity generated on the substrate W can be released to earth through the tactile sensors 6a, 6b, and 6c and the robot arm 2. This makes it possible to prevent damage to semiconductor devices due to static electricity and adhesion of airborne particles to the wafer.

[0057] The robot hand 3 may be configured to support the substrate W at four or more points instead of three points.

[0058] The tactile sensor may be disposed at one or more of the multiple locations where the robot hand 3 supports the substrate W. In order to avoid static electricity, it is preferable that the supporting locations where the tactile sensor is not disposed are made of an appropriate conductive material and electrically connected to the robot arm 2.

[0059] A tactile sensor that can detect forces on three axes plus three axes of moment, for a total of six axes, can also be used.

[0060] The robot hand 3 can also be modified to a configuration other than the passive grip type.

[0061] The robot 100 is preferably used in a vacuum environment where it is not possible to suction grip the substrate W by negative pressure, but the robot 100 can also be used in environments other than a vacuum environment. [Explanation of symbols]

[0062] 3 Robot hand (hand part) 6a, 6b, 6c Tactile sensors 100 Robot (Substrate transport robot) W substrate

Claims

1. A substrate transport robot that transports a substrate, Equipped with a hand part, The hand unit includes: A hand body, a tactile sensor having a sensing surface disposed above the hand body; Equipped with the hand unit supports the bottom surface of the substrate from below at three or more points, and the tactile sensor is disposed at at least one of the points; The substrate transport robot is characterized in that the tactile sensor is capable of detecting an externally applied force in three axial directions.

2. 2. The substrate transport robot according to claim 1, The substrate transport robot, wherein the hand portion is a passive grip type hand.

3. 3. The substrate transport robot according to claim 1, The substrate transport robot is characterized in that the tactile sensors are disposed at all points that support the lower surface of the substrate.

4. The substrate transport robot according to any one of claims 1 to 3, The substrate transport robot is characterized in that the hand portion has a branched tip, and the tactile sensor is disposed at each of the branched portions.

5. The substrate transport robot according to any one of claims 1 to 4, A substrate transport robot, characterized in that one or more of the tactile sensors are arranged on each of the tip side and base side of the hand portion.

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