Robot and substrate posture inspection method

Abstract

A robot for transporting a substrate includes a hand portion, an arm portion, a substrate detection portion, and a substrate posture inspection portion. The hand portion holds and transports the substrate. The arm portion is connected to the hand portion to move the hand portion. The substrate detection portion noncontactly detects the presence or absence of the substrate. The substrate posture inspection portion inspects the posture of the substrate based on a height of the substrate detected by the substrate detection portion in a state where the substrate is not held by the hand portion.

Description

Technical Field

[0001] This invention relates primarily to a robot for transporting substrates such as semiconductor wafers and printed circuit boards. More specifically, it relates to a structure for detecting the orientation of a substrate before holding it in place. Background Technology

[0002] Until now, robots for transporting substrates, which are used to remove substrates from substrate storage devices, substrate processing devices, etc., are well known. Patent Document 1 discloses a wafer transport device as such a robot.

[0003] Patent Document 1 describes a wafer transport device that includes a posture detection unit and an actuator. The posture detection unit detects the posture of a hand. The structure of the wafer transport device is such that the hand posture is adjusted by controlling the extension and retraction of the actuator based on the hand posture information detected by the posture detection unit.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2004-128021 Summary of the Invention

[0005] In the aforementioned Patent Document 1, the posture detection unit only detects the posture of the hand and cannot detect the posture of the substrate before it was held by the hand. If the posture of the substrate is incorrect, the substrate may be damaged during the robot's movement of holding the substrate.

[0006] In view of the above, the object of the present invention is to correctly detect the posture of the substrate of the transport object before the substrate is removed by a robot and held.

[0007] The problem to be solved by the present invention is as described above. The means used to solve the problem and its effects will be described below.

[0008] According to a first aspect of the present invention, a robot with the following structure is provided. That is, a robot for transporting a substrate includes an arm, a hand, a substrate detection unit, and a substrate posture checking unit. The hand is disposed on the arm and holds and transports the substrate. The substrate detection unit detects the presence or absence of the substrate non-contactly. The substrate posture checking unit checks the posture of the substrate based on height information detected by the substrate detection unit when the substrate is not held by the hand.

[0009] According to a second aspect of the present invention, a substrate posture inspection method is provided. That is, the substrate posture inspection method uses a robot that transports the substrate to inspect the posture of the substrate. The robot includes an arm, a hand, and a substrate detection unit. The hand is disposed on the arm and holds and transports the substrate. The substrate detection unit detects the presence or absence of the substrate non-contactly. The posture of the substrate is inspected based on the height information of the substrate detected by the substrate detection unit when it is not held by the hand.

[0010] Therefore, the substrate's orientation can be checked before it is removed from a substrate storage device or similar facility. This prevents accidental contact between the hand and the substrate due to improper orientation during hand movement. Consequently, damage to the substrate can be prevented.

[0011] (The effect of the invention)

[0012] According to the present invention, the posture of the substrate of the transport object can be correctly detected before the substrate is removed by a robot and held. Attached Figure Description

[0013] Figure 1 This is a perspective view showing the overall structure of a robot according to one embodiment of the present invention.

[0014] Figure 2 This is a perspective view showing an example of a tilting mechanism.

[0015] Figure 3 This is a cross-sectional view showing an example of a tilting mechanism.

[0016] Figure 4 This is a diagram showing the posture of a robot inspecting a substrate.

[0017] Figure 5 This is an enlarged view showing the robot hand moving up and down relative to the substrate.

[0018] Figure 6 This is an explanatory diagram showing the change in the detected thickness caused by the tilting of the substrate.

[0019] Figure 7 This is a plan view illustrating the tilt inspection of the substrate in the first modified example.

[0020] Figure 8 This is a plan view illustrating the tilt inspection of the substrate in the second modified example.

[0021] Figure 9 This is a diagram illustrating the concept of how the detection axis of the mapping sensor is oriented differently in order to detect the tilt of the substrate in the third variation. Detailed Implementation

[0022] Next, the disclosed embodiments will be described with reference to the accompanying drawings. Figure 1 This is a perspective view showing the overall structure of a robot 100 according to one embodiment of the present invention.

[0023] Figure 1 The robot 100 shown is installed, for example, in a manufacturing plant or warehouse for substrates W such as semiconductor wafers and printed circuit boards. The robot 100 is used to transport substrates W between a substrate processing apparatus and a substrate storage apparatus 7 described later. However, the robot 100 can also be used, for example, to transport substrates W between multiple substrate processing apparatuses that process substrates W. The substrate W can also be any one of the following: raw material for substrates, a semi-finished product in processing, or a finished product after processing. The shape of the substrate W is a circular plate in this embodiment, but it is not limited to this.

[0024] The robot 100 mainly includes a base 1, a robot arm (arm part) 2, a robot hand (hand part) 3, and a robot control unit (board posture inspection unit) 9.

[0025] The base 1 is fixed to the factory floor or the like. However, it is not limited to this; the base 1 may also be fixed to, for example, the housing of a substrate processing apparatus that includes the substrate processing device. Furthermore, the base 1 may also be fixed to a mobile trolley (not shown) that operates between the substrate processing apparatus (or equipment) and the substrate storage device 7.

[0026] like Figure 1 As shown, the robot arm 2 is mounted on the base 1 via a lifting shaft 11 that can move in the vertical direction. The robot arm 2 is capable of rotating relative to the lifting shaft 11.

[0027] Robotic arm 2 is composed of a horizontal multi-joint robotic arm. Robotic arm 2 includes a first arm 21 and a second arm 22.

[0028] The first arm 21 is constructed as a slender, horizontally extending straight section. One end of the first arm 21 along its length is mounted on the upper end of the lifting shaft 11. The first arm 21 is rotatably supported about the axis (vertical axis) of the lifting shaft 11. A second arm 22 is mounted on the other end of the first arm 21 along its length.

[0029] The second arm 22 is constructed as a slender, horizontally extending straight section. One end of the second arm 22 is mounted to the front end of the first arm 21 along its length. The second arm 22 is rotatably supported about an axis (vertical axis) parallel to the lifting shaft 11. A robotic hand 3 is mounted at the other end of the second arm 22 along its length.

[0030] Each of the lifting shaft 11, the first arm 21, and the second arm 22 is driven by a suitable actuator (not shown). This actuator can be, for example, an electric motor.

[0031] An encoder (not shown) is installed at 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 to detect the rotational position of each of the first arm 21, the second arm 22, and the robot hand 3. Furthermore, an encoder is also provided at an appropriate position on the robot 100 to detect the positional change of the first arm 21 in the height direction (i.e., the amount of lifting of the lifting shaft 11).

[0032] The robot control unit 9 controls the movement of the electric motors driving each of the lifting shaft 11, the first arm 21, the second arm 22, and the robot hand 3 based on position information including the rotational or height positions of the first arm 21, the second arm 22, or the robot hand 3 detected by each encoder. It should be noted that, in the following description, when referred to as "position information detected by the encoder," it means the combination of position information detected by each encoder that represents the posture of the robot 100.

[0033] like Figure 1 As shown, the robot hand 3 includes a wrist part 31 and a hand body part 32.

[0034] The wrist portion 31 is mounted on the front end of the second arm 22 via a tilting mechanism 4. The wrist portion 31 is rotatably supported about an axis (vertical axis) parallel to the lifting shaft 11. However, the tilting mechanism 4 can tilt the axis of rotation of the wrist portion 31 relative to a straight line parallel to the lifting shaft 11. The detailed structure of the tilting mechanism 4 will be described later. The wrist portion 31 is driven to rotate by a suitable actuator (not shown). This actuator can be, for example, an electric motor. A hand body portion 32 is connected to the wrist portion 31. The wrist portion 31 and the hand body portion 32 can also be formed as one piece.

[0035] The hand body portion 32 is the part that functions to hold the substrate W. The hand body portion 32 is composed of a plate-shaped component formed in a Y-shape (or U-shape). The hand body portion 32 is divided into two forks on the side opposite to the side connected to the wrist portion 31 (in other words, the front end side). In the following description, the various parts of the branches are sometimes referred to as the first finger portion 32a and the second finger portion 32b.

[0036] The first finger portion 32a and the second finger portion 32b are formed symmetrically to each other. For example... Figure 4 as well as Figure 5As shown, an appropriate gap is formed between the front end portions of the first finger portion 32a and the second finger portion 32b. Therefore, the edge portion of the substrate W can be positioned between the front end portions of each of the first finger portion 32a and the second finger portion 32b without the robot hand 3 contacting the substrate W.

[0037] In this embodiment, a plurality of guide portions 33 for holding the substrate W are provided on both the front end side and the base end side of the hand body portion 32. Each guide portion 33 is made of, for example, rubber. The guide portion 33 is configured to protrude upward from the plate-shaped hand body portion 32. Figure 1 As shown, for example, one guide portion 33 is provided on each of the first finger portion 32a and the second finger portion 32b, and two are provided on the base end side of the hand body portion 32.

[0038] like Figure 1 As shown, the guide portion 33 contacts the lower surface near the periphery of the substrate W placed on the robot arm 3, holding the substrate W in place. The guide portion 33 can prevent the substrate W placed on the robot arm 3 from deviating in the horizontal direction by contacting the edge of the substrate W from the outside in the diametrical direction.

[0039] The structure by which the robotic arm 3 holds the substrate W is not limited to the structure described above. For example, the robotic arm 3 can also hold the substrate W by using a structure that adsorbs the upper or lower surface of the substrate W with negative pressure. For example, the robotic arm 3 can also include a well-known Bernoulli suction cup to hold the substrate W non-contactly.

[0040] The tilting mechanism 4 is installed on the front end side of the second arm 22 (opposite to the side connected to the first arm 21).

[0041] like Figure 2 As shown, the tilting mechanism 4 includes a lower plate portion 41 and an upper plate portion 42. The lower plate portion 41 is fixed to the upper surface of the second arm 22. The wrist portion 31 of the robot hand 3 is rotatably supported by the upper plate portion 42. A height adjustment mechanism 5 is disposed between the lower plate portion 41 and the upper plate portion 42. The tilting mechanism 4 uses the height adjustment mechanism 5 to adjust the tilt angle and tilt direction of the upper plate portion 42 relative to the lower plate portion 41.

[0042] like Figure 2 As shown, the height adjustment mechanism 5 includes, for example, three support parts 51, 52, and 53, which are disposed at different positions between the lower plate part 41 and the upper plate part 42. For ease of explanation, in... Figure 3 The central support sections 51, 52, and 53 are depicted as arranged in a straight line; in reality, as shown... Figure 2 As shown, from a plan view, the support parts 51, 52, and 53 are configured to form a triangle.

[0043] Two of the three support portions 51 and 52 include an external thread 56, an internal thread 57, and a spherical bearing 58. The threaded shaft of the external thread 56 is rotatably supported by the lower plate portion 41 with its axis pointing vertically. This threaded shaft can be independently rotated in the two support portions 51 and 52 by an actuator (e.g., an electric motor) omitted from the illustration. The internal thread 57 is screwed onto the threaded shaft of the external thread 56. When the threaded shaft is rotated, the internal thread 57 moves vertically. By this threaded feed, the height at which the support portions 51 and 52 support the upper plate portion 42 can be changed. A spherical bearing 58 is disposed between the internal thread 57 and the upper plate portion 42.

[0044] The remaining support portion 53 is equipped with a spherical bearing 58. This support portion 53 does not have the function of changing the support height due to threaded feed.

[0045] By driving an electric motor, the height of the upper plate 42 relative to the lower plate 41 can be independently changed at multiple support sections 51 and 52, thereby changing the tilt angle and tilt direction of the upper plate 42 relative to the lower plate 41. As a result, the posture (tilt angle and tilt direction) of the robot hand 3 relative to the second arm 22 can be adjusted. It should be noted that the height adjustment mechanism 5 (and even the tilting mechanism 4) is not limited to this structure.

[0046] The robot control unit 9 stores the detection results of the encoder corresponding to the posture of the robot hand 3 as the posture information of the robot hand 3. Therefore, the robot control unit 9 can control the electric motors of various parts driving the robot 100 (lifting shaft 11, first arm 21, second arm 22, robot hand 3, etc.) to make the detection results of the encoder that detects the posture of the robot hand 3 consistent with the stored posture information, so as to reproduce the posture of the robot hand 3.

[0047] like Figure 1 As shown, a mapping sensor 6 (substrate detection unit) is provided on the front end side of the hand body 32. The mapping sensor 6 enables non-contact confirmation (mapping) of the presence or absence of the substrate W. In this embodiment, the mapping sensor 6 is, for example, a transmissive sensor having a light-emitting part 61 and a light-receiving part 62. It should be noted that this is not a limitation; the mapping sensor 6 may also be, for example, a reflective sensor.

[0048] like Figure 1 as well as Figure 4 As shown, a light-projecting part 61 is provided on the front end side of the first finger part 32a. A light-receiving part 62 is provided on the front end side of the second finger part 32b. The light-projecting part 61 illuminates a detection light toward the light-receiving part 62. The detection light can be, for example, infrared light, but is not limited to this.

[0049] The light-receiving unit 62 is connected to the robot control unit 9 wirelessly or via a wired connection. The light-receiving unit 62 outputs an electrical signal to the robot control unit 9 indicating the presence or absence of detected light. When there is no object (e.g., substrate W) between the light-projecting unit 61 and the light-receiving unit 62, the light-receiving unit 62 outputs an electrical signal indicating that it has received light because the detected light from the light-projecting unit 61 reaches the light-receiving unit 62. When there is an object between the light-projecting unit 61 and the light-receiving unit 62, the light-receiving unit 62 outputs an electrical signal indicating that it has not received light because the detected light from the light-projecting unit 61 is blocked by the substrate W.

[0050] When multiple substrates W are arranged at appropriate intervals in the vertical direction within the substrate storage device 7, the robot control unit 9 moves the robot hand 3 vertically across these multiple arrangement positions (mapping operation) while bringing the front end of the robot hand 3 close to the vicinity of the arrangement position. At this time, assuming a substrate W is present at the arrangement position, the position of the robot hand 3 as viewed from the plane is such that the robot hand 3 is not in contact with the substrate W, and the position of the substrate W can be detected by the mapping sensor 6. The presence or absence of substrate W at each arrangement position can be obtained based on the time-series data output by the mapping sensor 6 when the robot hand 3 moves vertically.

[0051] However, it is not limited to this. For example, the presence or absence of the substrate W in each position information detected by the encoder can be obtained based on the output of the mapping sensor 6 at each position of the robot hand 3 when the robot hand 3 moves in the vertical direction. That is, the presence or absence information of the substrate W obtained by the output of the mapping sensor 6 is associated with the position information detected by the encoder.

[0052] As long as the light-receiving part 62 can detect the light from the light-projecting part 61, the positions of the light-projecting part 61 and the light-receiving part 62 in the robot hand 3 can be arbitrary. For example, the light-projecting part 61 can be hidden inside the first finger part 32a, and the light-receiving part 62 can be hidden inside the second finger part 32b.

[0053] like Figure 1 As shown, the robot control unit 9 and the base 1 are respectively provided. However, the robot control unit 9 can also be configured inside the base 1. The robot control unit 9 is a well-known computer configuration, including an arithmetic processing unit such as a microcontroller, CPU, MPU, PLC, DSP, ASIC, or FPGA, a storage unit such as ROM, RAM, or HDD, and a communication unit capable of communicating with external devices. The storage unit stores programs executed by the arithmetic processing unit, various set thresholds, and shape data such as the thickness and size of the substrate W to be transported. The communication unit is configured to send detection results from various sensors (e.g., mapping sensor 6, encoder, etc.) to external devices and to receive information about the substrate W from external devices.

[0054] Next, refer to Figures 4 to 6 The inspection of the posture of the substrate W transported by the robot 100 of this embodiment will be described in detail. It should be noted that the following description uses an example of inspecting the posture of the substrate W stored in the substrate storage device 7. Furthermore, to make the structure of each part easier to understand, some parts of the structure may be omitted in the accompanying drawings.

[0055] Figure 4 The substrate storage device 7 shown is used to store substrate W. In the substrate storage device 7, a plurality of substrates (e.g., more than 100) are stored in a state in which they are arranged at equal intervals in the vertical direction (the height direction of the substrate storage device 7).

[0056] In the substrate storage device 7, the substrate W is usually stored in a horizontal position. However, due to reasons such as deformation of the partition or the presence of foreign objects, the substrate W is sometimes stored in the substrate storage device 7 in a non-horizontal position. The robot 100 of this embodiment can check the position (tilt relative to the horizontal plane or the robot arm 3) of the substrate W before taking it out of the substrate storage device 7 for transport.

[0057] The tilt of the substrate W can occur in three dimensions. In this embodiment, when the substrate W is viewed horizontally along the direction in which the robot hand 3 is inserted into the substrate storage device 7 (hereinafter referred to as the hand insertion direction), the tilt of the substrate W relative to the horizontal can be checked. In other words, the object of inspection is the tilt of the substrate W in the tumbling direction relative to the hand insertion direction.

[0058] Specifically, such as Figure 4 As shown, the robot control unit 9 moves the robot hand 3, keeping its hand body 32 horizontal, so that a portion of the substrate W to be inspected is positioned between the first finger portion 32a and the second finger portion 32b. At this time, the detection light of the mapping sensor 6 is directed parallel to the appropriate posture of the substrate W.

[0059] Then, the robot control unit 9 moves the robot hand 3 vertically while maintaining a horizontal posture by moving the lifting axis 11 vertically. This is achieved by scanning the vertical direction using the mapping sensor 6. Figure 5 As shown, for example, the robot arm 3 moves from below the substrate W of the object being inspected upwards or from above downwards. Preferably, when the moving speed of the robot arm 3 is kept constant, the inspection thickness TH1, which will be described later, can be easily calculated.

[0060] When a portion of the substrate W passes between the first finger portion 32a and the second finger portion 32b of the robot hand 3, the light emitted from the light-projecting section 61 is blocked by the substrate W. As a result, the output signal of the light-receiving section 62 is, for example, as... Figure 5The shape changes like that.

[0061] The robot control unit 9 analyzes time-series data based on the output from the light-receiving unit 62 to determine the blocking time t0 during the vertical movement of the robot hand 3, during which the light from the light-projecting unit 61 is blocked by the substrate W of the object being inspected. In other words, this blocking time t0 can also be referred to as the detection time when the substrate W is detected by the mapping sensor 6. The robot control unit 9 calculates the detection thickness TH1 of the substrate W as the distance the robot hand 3 moves in the vertical direction within the determined blocking time t0. This detection thickness TH1 is the difference between the maximum and minimum values ​​of the detected height (height information) of the substrate W.

[0062] like Figure 6 As shown, when the substrate W is horizontally positioned relative to the robot arm 3, the distance by which light from the light-emitting section 61 is blocked is only the actual thickness TH of the substrate W. On the other hand, when the substrate W is tilted relative to the robot arm 3, the distance by which light from the light-emitting section 61 is blocked is greater than the actual thickness TH of the substrate W.

[0063] Therefore, the robot control unit 9 determines whether the substrate W to be inspected is tilted by comparing the detected thickness TH1 of the substrate W calculated as described above with the actual thickness TH of the substrate W stored by the storage unit.

[0064] Various methods can be used to determine this. For example, one method is to compare the difference between the detected thickness TH1 and the actual thickness TH of the substrate W to be inspected with a predetermined allowable threshold. When the difference exceeds the allowable threshold, the robot control unit 9 determines that the substrate W to be inspected is tilted.

[0065] The actual thickness TH of substrate W can be calculated in advance based on the design and manufacturing data of substrate W, or it can be obtained by measuring the average thickness of multiple substrates W. The robot control unit 9 receives the actual thickness TH obtained as described above from an external device via the communication unit and stores it in the storage unit.

[0066] When the robot control unit 9 determines that the substrate W is tilted, it performs appropriate control. Examples of control include removing the substrate W from the transported objects or stopping the operation. In this way, since the robot arm 3 will not enter the improperly positioned substrate W, damage to the substrate W due to contact with the robot arm 3 can be prevented.

[0067] When multiple substrates W are arranged vertically, the posture of the multiple substrates W can be checked by a single vertical movement of the robot arm 3. Preferably, when the time-series data of the mapping sensor 6 used to confirm the presence or absence of substrates W and check the posture of substrates W is obtained by a single vertical movement of the robot arm 3, the cycle time can be shortened.

[0068] As described above, the robot 100 of this embodiment is used to transport a substrate W. The robot 100 includes a robot arm 2, a robot hand 3, a mapping sensor 6, and a robot control unit 9. The robot hand 3 is disposed on the robot arm 2 and holds and transports the substrate W. The mapping sensor 6 detects the presence or absence of the substrate W non-contactly. The robot control unit 9 checks the posture of the substrate W based on the height detected by the mapping sensor 6 when the substrate W is not held by the robot hand 3.

[0069] Therefore, the orientation of the substrate W can be checked before it is removed from the substrate storage device 7, etc. This prevents accidental contact between the robot arm 3 and the substrate W due to improper orientation during robot arm 3 movement. Consequently, damage to the substrate W can be prevented.

[0070] Furthermore, in the robot 100 of this embodiment, a mapping sensor 6 is provided on the robot hand 3. The robot control unit 9 calculates the maximum and minimum values ​​of the height detected by the substrate W based on the output from the mapping sensor 6 when the robot hand 3 moves in the vertical direction. The robot control unit 9 checks the posture of the substrate W based on the detected thickness TH1, which is the difference between the upper and lower limits, and the actual thickness TH, which is the actual thickness of the substrate W.

[0071] Therefore, the orientation of the substrate W can be easily and accurately inspected using a simple structure.

[0072] Furthermore, the robot 100 of this embodiment includes a tilting mechanism 4, which enables the robot hand 3 to tilt in any direction.

[0073] Therefore, the orientation of the mapping sensor 6, which serves as a reference for posture inspection of the substrate W, can be adjusted with a high degree of freedom.

[0074] Next, a first variation of the described embodiment will be explained. Figure 7 This is a plan view illustrating the tilt inspection of the substrate W in the first modified example. It should be noted that in the description of this modified example, the same symbols are used to label components that are the same as or similar to those in the described embodiment, and descriptions are sometimes omitted.

[0075] In this variant, the robot 100 includes a rangefinder 6x in addition to the mapping sensor 6. The rangefinder 6x, together with the mapping sensor 6, constitutes a substrate detection unit. The rangefinder 6x is used to detect the tilt of the substrate W relative to the horizontal when viewed horizontally in a direction perpendicular to the hand insertion direction. In other words, the object inspected by the rangefinder 6x is the tilt of the substrate W in the pitch direction relative to the hand insertion direction. In this embodiment, the detection result of the rangefinder 6x corresponds to height information.

[0076] A 6x rangefinder, for example, consists of a laser displacement meter, an ultrasonic distance sensor, etc. Figure 7 As shown, the rangefinder 6x is, for example, disposed on the upper surface of the second finger portion 32b of the hand body portion 32. The rangefinder 6x non-contactly detects the vertical distance from the rangefinder 6x to the lower surface of the substrate W. The rangefinder 6x is wirelessly or wired connected to the robot control unit 9 and transmits the distance measured at the measurement position to the substrate W to the robot control unit 9.

[0077] The robot control unit 9 inserts the robot hand 3 under the substrate W supported by the substrate storage device 7. This positions the substrate W vertically relative to the rangefinder 6x. However, in this state, the substrate W is not held by the guide unit 33. The robot control unit 9 moves the robot hand 3 horizontally along the insertion direction in this state to measure the distance from the rangefinder 6x to the substrate W being inspected at at least two locations.

[0078] The robot control unit 9 determines whether the substrate W is tilted relative to the horizontal direction based on the difference in height of the substrate W measured by the rangefinder 6x at two points on the substrate W.

[0079] Assuming the substrate W is absent, the rangefinder 6x measures values ​​that are normally unattainable. Therefore, it can be said that the rangefinder 6x is essentially a sensor capable of detecting the presence or absence of the substrate W.

[0080] In the described embodiment, the tilt of the substrate W in the roll direction when viewed along the hand insertion direction can be detected by the mapping sensor 6. In this modified example, in addition to the above, the tilt in the pitch direction can also be detected by the rangefinder 6x. Therefore, in this modified example, the tilt of the substrate W can be detected in three dimensions.

[0081] As described above, in the robot 100 of this modified example, a rangefinder 6x is provided on the hand body 32 to measure the distance to the substrate W in the vertical direction. The robot control unit 9 checks the posture of the substrate W based on each of the distances measured by the rangefinder 6x at multiple points on the substrate W.

[0082] Therefore, the orientation of the substrate W can be easily and accurately inspected using a simple structure.

[0083] Next, a second variation of the described embodiment will be explained. Figure 8 This is a plan view conceptually illustrating the tilt inspection of the substrate W in the second modified example. It should be noted that in the description of this modified example, the same symbols are used to denote components that are the same as or similar to those in the described embodiment, and descriptions are sometimes omitted.

[0084] In this modified example, the robot 100, as a substrate detection unit, only includes the mapping sensor 6. In other words, the robot 100 does not include the rangefinder 6x.

[0085] like Figure 8 As shown by the solid line, in this modified example, the robot 100 performs measurements in the same manner as in the described embodiment, while simultaneously adjusting the orientation of the detection light from the mapping sensor 6 from a planar perspective, to obtain the detection thickness TH1. As described above, tilt can be determined by comparing the detection thickness TH1 with the actual thickness TH. The orientation of the detection light is not limited to... Figure 8 The example shown allows for various modifications.

[0086] In this modified example, the tilt of the substrate W can be inspected in three dimensions using two detection thicknesses TH1.

[0087] Next, a third variation of the described embodiment will be explained. Figure 9 This diagram is a conceptual illustration of how the detection axis of the mapping sensor 6 is oriented differently in order to detect the tilt of the substrate W in the third variation. It should be noted that in this description of the variation, the same reference numerals are used for components that are the same as or similar to those in the described embodiment, and descriptions are sometimes omitted.

[0088] like Figure 9 As shown, in this modified example, the robot control unit 9 appropriately changes the orientation and magnitude of the detection light from the mapping sensor 6, and calculates the detection thickness TH1 multiple times. Specifically, the robot control unit 9 tilts the robot hand 3 appropriately from horizontal to tilt the orientation of the detection light from the mapping sensor 6 towards the tumbling direction. Then, the robot control unit 9 moves the robot hand 3 in the vertical direction to calculate the detection thickness TH1 in the tilted state of the robot hand 3.

[0089] After repeatedly calculating the detected thickness TH1 as described above, the robot control unit 9 calculates the tilt angle of the detection light when the difference between the detected thickness TH1 and the actual thickness TH is minimized. This tilt angle represents the tilt angle θ of the tumbling direction of the substrate W. This tilt angle θ can be used as an indicator of how much the substrate W has deviated from the correct posture.

[0090] As described above, in the robot 100 of this modified example, the robot control unit 9 obtains the tilt angle θ, which indicates the magnitude of the tilt of the substrate W, by performing an inspection while changing the posture of the robot hand 3 using the tilting mechanism 4.

[0091] Therefore, the orientation of the substrate W can be specifically detected.

[0092] The preferred embodiments and variations of the present invention have been described above. The above structure can also be modified as follows.

[0093] The thickness TH1 can also be calculated based on the encoder's detection results (position information detected by the encoder) at the moments when the mapping sensor 6 begins to output no light and ends no light output, instead of calculating it based on the distance the robot hand 3 moves in the vertical direction during the period when the mapping sensor 6 outputs no light. In this case, the position information detected by the encoder is equivalent to the height information. It should be noted that when the robot hand 3 is kept in a fixed posture, and the robot hand 3 moves in the vertical direction to detect the presence or absence of the detection substrate W, the encoder's detection result of detecting the position change of the first arm 21 in the height direction (the amount of lifting of the lifting shaft 11) can be used only for calculating the thickness TH1.

[0094] The robot 100 can also indirectly transport the substrate W by holding a tray or other means that hold the substrate W, instead of directly transporting the substrate W.

[0095] The hand body 32 of the robot hand 3 can also be integrated with the upper plate 42 of the tilting mechanism 4.

[0096] The tilting mechanism 4 can be configured between the base 1 and the lifting shaft 11, between the lifting shaft 11 and the first arm 21, or between the first arm 21 and the second arm 22.

[0097] exist Figure 5 as well as Figure 6 In the illustrated embodiment, the positions of the light-emitting portion 61 and the light-receiving portion 62 of the mapping sensor 6 relative to the substrate W, viewed from a plane, can also be determined in some way, and the tilt angle θ of the substrate W can be calculated. This calculation can be easily performed by geometric calculation based on the detection thickness TH1. Figure 7 as well as Figure 8 The same applies to the variant examples shown.

[0098] exist Figure 7In the first modified example shown, the mapping sensor 6 can be omitted. In this case, the tilt of the substrate W in the pitch direction can be checked by horizontally scanning the rangefinder 6x along the hand insertion direction. Furthermore, while the robot hand 3 is moved appropriately in the horizontal plane, the height of point 3 in the substrate W, which forms a triangle when viewed from the plane, can be measured using the rangefinder 6x. In this case, the tilt of the substrate W can be checked in three dimensions using only the rangefinder 6x.

[0099] Alternatively, in the robot hand 3 of the first variant, multiple rangefinders 6x can be configured in different positions.

[0100] The inspection of the tilt of the substrate W can also be performed by a separate inspection device instead of the robot control unit 9.

[0101] The functions of the elements disclosed in this specification can be executed using circuitry or processing circuitry, which includes general-purpose processors, special-purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and / or combinations thereof configured or programmed to perform the disclosed functions. A processor, because it contains transistors and other circuitry, is considered a processing circuit or circuit. In this invention, a circuit, unit, or component is hardware that performs the listed functions or hardware programmed to perform the listed functions. The hardware can be either the hardware disclosed in this specification or other known hardware programmed or configured to perform the listed functions. When the hardware is a processor considered a type of circuit, the circuit, component, or unit is a combination of hardware and software, with the software used in the structure of the hardware and / or processor.

Claims

1. A robot for transporting substrates, characterized in that: The robot includes an arm, a hand, a substrate detection unit, and a substrate posture checking unit. The hand is disposed on the arm and holds and transports the substrate. The substrate detection unit includes a mapping sensor disposed on the hand for non-contact detection of the presence or absence of the substrate. The substrate posture checking unit checks the posture of the substrate based on the height information detected by the substrate detection unit when the substrate is not held by the hand. The substrate posture checking unit calculates the maximum and minimum detected heights of the substrate based on the output from the mapping sensor when the hand moves in the vertical direction, and calculates the difference between the maximum and minimum values, which is the detected thickness. By tilting the hand to change the orientation of the detection light from the mapping sensor, the detection thickness of the substrate is determined multiple times. The orientation of the substrate is checked by the tilt angle of the detection light, which is minimized when the difference between the detected thickness and the actual thickness of the substrate is minimized.

2. The robot according to claim 1, characterized in that: The substrate detection unit includes a rangefinder, which is mounted on the hand to measure the vertical distance to the substrate. The substrate posture checking unit checks the posture of the substrate based on each of the distances measured by the rangefinder at multiple points on the substrate.

3. The robot according to claim 1 or 2, characterized in that: The robot includes a tilting mechanism that allows the hand to tilt in any direction.

4. The robot according to claim 3, characterized in that: The substrate posture checking unit uses the tilting mechanism to check the substrate's tilt size while the hand posture is being changed, thereby obtaining the tilt size of the substrate.

5. A substrate posture inspection method, wherein the substrate posture is inspected by a robot that transports the substrate, the robot comprising an arm, a hand, and a substrate detection unit, the hand being disposed on the arm to hold and transport the substrate, and the substrate detection unit comprising a mapping sensor disposed on the hand to detect the presence or absence of the substrate non-contactly, characterized in that: The posture of the substrate is checked based on the height information of the substrate detected by the substrate detection unit when it is not held by the hand. Based on the output from the mapping sensor when the hand moves vertically, the maximum and minimum detected heights of the substrate are determined, and the difference between the maximum and minimum values, i.e., the detected thickness, is calculated. By tilting the hand to change the orientation of the detection light from the mapping sensor, the detection thickness of the substrate is determined multiple times. The orientation of the substrate is checked by the tilt angle of the detection light, which is minimized when the difference between the detected thickness and the actual thickness of the substrate is minimized.

Images