Industrial robot and control method for industrial robot

Abstract

To provide an industrial robot capable of narrowing a space between two mounting parts in a vertical direction while preventing interference between a conveyed object held on one mounting part and a conveyed object mounted on the other mounting part even when the one mounting part holding the conveyed object rotates with a horizontal direction set as an axial direction of the rotation in a state where the two mounting parts are stacked in the vertical direction.SOLUTION: In an industrial robot 1, a hand 4 has a detection mechanism for detecting whether a conveyed object 2 is mounted on a mounting part 37. In this industrial robot 1, when a mounting part 17 for holding the conveyed object 2 rotates with respect to a hand base 18 with a horizontal direction set as an axial direction of the rotation, the mounting part 37 is stopped with the surface of a side on which the conveyed object 2 is mounted up. When non-mounting of the conveyed object 2 on the mounting part 37 is detected by the detection mechanism, the mounting part 17 is rotated, and the conveyed object 2 held on the mounting part 17 is vertically reversed.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an industrial robot for transporting an object, and also to a control method for an industrial robot for transporting an object. [Background technology]

[0002] Conventionally, there is known a transfer robot that grips and transports a disk-shaped substrate and an annular sheet-like member used when subjecting the substrate to a water vapor annealing treatment (see, for example, Patent Document 1). The transfer robot described in Patent Document 1 includes a gripping hand that grips the substrate and the sheet-like member, and a movement mechanism that moves the gripping hand three-dimensionally. The movement mechanism includes a base, an elevating mechanism that is mounted on the base so that it can be raised and lowered, and a multi-joint arm that is mounted on the elevating mechanism so that it can rotate and expand. The movement mechanism also includes a direction-changing mechanism that rotates the gripping hand around a horizontal axis that is parallel to the horizontal direction, thereby turning upside down the substrate and sheet-like member gripped by the gripping hand. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-158170 Summary of the Invention [Problem to be solved by the invention]

[0004] The present inventors have developed an industrial robot for transporting objects such as semiconductor wafers, which includes two hands on which the objects are mounted. The two hands each include a mounting portion on which the objects are mounted. The present inventors are considering arranging the two mounting portions of this industrial robot with a vertical gap between them so that the mounting portion of one hand is located above the mounting portion of the other hand. The present inventors are also considering rotating at least one of the two mounting portions of this industrial robot around a horizontal axis, as in the gripping hand described in Patent Document 1.

[0005] In the case of this industrial robot, when the two mounting units are stacked vertically and one mounting unit on which an object to be transported is mounted rotates about the horizontal direction as its axis of rotation, it is necessary to ensure that the object to be transported mounted on the other mounting unit does not interfere with the object to be transported mounted on one mounting unit. On the other hand, if the spacing between the two mounting units in the vertical direction is set so that the object to be transported mounted on the other mounting unit does not interfere with the object to be transported mounted on one mounting unit when the two mounting units are stacked vertically and one mounting unit on which an object to be transported is mounted rotates about the horizontal direction as its axis of rotation, the spacing between the two mounting units in the vertical direction will become wider, which could result in an increase in the size of the industrial robot and a wider operating area for the two mounting units.

[0006] Therefore, the object of the present invention is to provide an industrial robot that has two hands each having a mounting portion capable of mounting an object to be transported, and that is capable of narrowing the distance between the two mounting portions in the vertical direction while preventing interference between the object to be transported mounted on the other mounting portion and the object to be transported held on one mounting portion, even when the two mounting portions are overlapped in the vertical direction and one mounting portion holding the object to be transported rotates with the horizontal direction as the axis of rotation.

[0007] Another object of the present invention is to provide a control method for an industrial robot having two hands with mounting parts capable of mounting an object to be transported, which can narrow the distance between the two mounting parts in the vertical direction while preventing interference between the object to be transported mounted on the other mounting part and the object to be transported held on one mounting part, even when the two mounting parts are overlapped in the vertical direction and one mounting part holding the object to be transported rotates with the horizontal direction as the axis of rotation. [Means for solving the problem]

[0008] In order to solve the above problems, the industrial robot of the present invention is an industrial robot for transporting an object to be transported, and includes a first hand and a second hand on which the object to be transported is mounted, and a control unit for controlling the industrial robot, the first hand includes a first mounting unit on which the object to be transported can be mounted and which can hold the mounted object to be transported, a first hand base portion constituting the base end side portion of the first hand, and a rotation mechanism for rotating the first mounting unit by at least 180° with respect to the first hand base portion about the horizontal direction as the axis of rotation, and the second hand includes a second mounting unit on which the object to be transported can be mounted, and a control unit for controlling the industrial robot, and a detection mechanism for detecting whether an object is loaded or not, wherein either the first loading section or the second loading section is arranged above the other of the first loading section or the second loading section, and the surface of the second loading section on which the object to be transported is loaded is defined as the loading surface, when the first loading section holding the object to be transported rotates relative to the first hand base, the second loading section stops with its loading surface facing upward or downward, and when the detection mechanism detects that the object to be transported is not loaded on the second loading section, the control section rotates the first loading section to turn the object to be transported held by the first loading section upside down.

[0009] In order to solve the above-mentioned problems, the present invention provides a method for controlling an industrial robot, which includes a first hand and a second hand on which an object to be transported is mounted, the first hand including a first mounting section on which the object to be transported can be mounted and which can hold the mounted object to be transported, a first hand base section constituting a base end portion of the first hand, and a rotation mechanism which rotates the first mounting section by at least 180° relative to the first hand base section with the horizontal direction as the axis of rotation, and the second hand including a second mounting section on which the object to be transported can be mounted, and a detector for detecting whether or not the object to be transported is mounted on the second mounting section. and a mechanism for controlling an industrial robot, wherein one of the first mounting section and the second mounting section is arranged above the other of the first mounting section and the second mounting section, and the surface of the second mounting section on which the object to be transported is mounted is defined as the mounting surface, and when the first mounting section holding the object to be transported rotates relative to the first hand base, the second mounting section is stopped with its mounting surface facing upward or downward, and when the detection mechanism detects that the object to be transported is not mounted on the second mounting section, the first mounting section is rotated to turn the object to be transported held by the first mounting section upside down.

[0010] In the present invention, the second hand includes a detection mechanism for detecting whether or not an object to be transported is mounted on the second mounting unit. Also, in the present invention, when the detection mechanism detects that an object to be transported is not mounted on the second mounting unit, the first mounting unit is rotated to turn the object to be transported held by the first mounting unit upside down.

[0011] Therefore, in the present invention, even if the distance between the first mounting unit and the second mounting unit in the up-down direction is narrowed, when the first mounting unit that holds the object to be transported rotates about the horizontal direction as the axis of rotation with the first mounting unit and the second mounting unit overlapping each other in the up-down direction, the object to be transported mounted on the second mounting unit and the object to be transported held on the first mounting unit do not interfere with each other. In other words, in the present invention, even if the first mounting unit and the second mounting unit overlap each other in the up-down direction and the first mounting unit that holds the object to be transported rotates about the horizontal direction as the axis of rotation, it is possible to narrow the distance between the first mounting unit and the second mounting unit in the up-down direction while preventing interference between the object to be transported mounted on the second mounting unit and the object to be transported held on the first mounting unit.

[0012] In the present invention, for example, the industrial robot includes a first arm having a first hand rotatably connected to a tip end thereof, a second arm having a second hand rotatably connected to a tip end thereof, and a base end of the first arm and a second arm. Mu's and a main body part to which the base end side is rotatably connected, the first hand is rotatable relative to the first arm with the vertical direction as the axis of rotation, the second hand is rotatable relative to the second arm with the vertical direction as the axis of rotation, the first arm and the second arm are rotatable relative to the main body part with the vertical direction as the axis of rotation, the first arm is extendable and contractible in a direction in which the tip of the first hand approaches the main body part and a direction in which the tip of the first hand moves away from the main body part, and the second arm is extendable and contractible in a direction in which the tip of the second hand approaches the main body part and a direction in which the tip of the second hand moves away from the main body part, when the first arm is retracted and the second arm is retracted in a predetermined standard state, the first mounting part and the second mounting part overlap in the vertical direction, and when the detection mechanism detects that no object to be transported is mounted on the second mounting part when in the standard state, the control part rotates the first mounting part to turn the object to be transported held by the first mounting part upside down.

[0013] In the present invention, for example, the object to be transported is formed in a disk shape, the first mounting unit and the second mounting unit include two linear mounting unit bodies on which the object to be transported is mounted, and the two mounting unit bodies are arranged parallel to each other and spaced apart in a direction perpendicular to the longitudinal direction of the mounting unit bodies. In this case, during the process of turning the object to be transported held by the first mounting unit upside down, a part of the object to be transported held by the first mounting unit is temporarily placed between the two mounting unit bodies of the second mounting unit.

[0014] In the present invention, for example, the second mounting section includes an end surface contact member having a contact surface against which the end surface of the object to be transported contacts, the second hand includes a pressing member that presses the object to be transported against the contact surface and a movement mechanism that moves the pressing member, and the detection mechanism detects the position of the pressing member when the pressing member moves in the direction in which the object to be transported is pressed against the contact surface. In this case, it becomes possible to detect whether the object to be transported is mounted on the second mounting section by using the pressing member that presses the object to be transported against the contact surface. [Effects of the Invention]

[0015] As described above, in the present invention, in an industrial robot equipped with two hands each having a mounting portion capable of mounting an object to be transported, when the two mounting portions are stacked vertically, even if one of the mounting portions holding the object to be transported rotates with the horizontal direction as the axis of rotation, it is possible to narrow the distance between the two mounting portions in the vertical direction while preventing interference between the object to be transported mounted on the other mounting portion and the object to be transported held on one of the mounting portions. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a perspective view of an industrial robot according to an embodiment of the present invention; [Figure 2] FIG. 2 is a side view of the industrial robot shown in FIG. [Figure 3] 3 is a side view of the first mounting portion shown in FIG. 2 when it is rotating. FIG. [Figure 4] FIG. 2 is a plan view of the industrial robot shown in FIG. [Figure 5] FIG. 2 is a block diagram for explaining the configuration of the first hand and the second hand shown in FIG. [Figure 6] 1. FIG. 4 is a diagram for explaining a detection method for detecting whether or not an object to be transported is placed on the second hand shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0018] (Overall structure of industrial robots) Fig. 1 is a perspective view of an industrial robot 1 according to an embodiment of the present invention. Fig. 2 is a side view of the industrial robot 1 shown in Fig. 1. Fig. 3 is a side view of the mounting unit 17 shown in Fig. 2 when it is rotating. Fig. 4 is a plan view of the industrial robot 1 shown in Fig. 1.

[0019] The industrial robot 1 (hereinafter referred to as "robot 1") of this embodiment is a horizontal articulated robot for transporting a semiconductor wafer 2 (hereinafter referred to as "wafer 2"), which is an object to be transported. The wafer 2 is formed in a disk shape. The robot 1 includes two hands 3 and 4 on which the wafer 2 is mounted, an arm 5 to which the tip end of the hand 3 is rotatably connected, and an arm 6 to which the tip end of the hand 4 is rotatably connected. In this embodiment, the hand 3 is a first hand, the hand 4 is a second hand, the arm 5 is a first arm, and the arm 6 is a second arm.

[0020] The robot 1 also includes a main body 7 to which the base ends of the arms 5 and 6 are rotatably connected, an elevator 8 to which the main body 7 is rotatably connected, and a holder 9 that holds the elevator 8 so that it can be raised and lowered. The arms 5 and 6 are each composed of two arm sections 12 and 13 that are rotatably connected to each other. The base end of the arm section 12 is rotatably connected to the main body 7. The base end of the arm section 13 is rotatably connected to the tip end of the arm section 12. The hands 3 and 4 are rotatably connected to the tip end of the arm section 13.

[0021] The main body 7 is rotatable relative to the lifting unit 8, with the up-down direction (vertical direction) as the axial direction of the rotation. The arm 12 is rotatable relative to the main body 7, with the up-down direction as the axial direction of the rotation. That is, the arms 5 and 6 are rotatable relative to the main body 7, with the up-down direction as the axial direction of the rotation. The arm 13 is rotatable relative to the arm 12, with the up-down direction as the axial direction of the rotation.

[0022] The hands 3 and 4 are rotatable relative to the arm unit 13 with the vertical direction as the axis of rotation. That is, the hand 3 is rotatable relative to the arm 5 with the vertical direction as the axis of rotation, and the hand 4 is rotatable relative to the arm 6 with the vertical direction as the axis of rotation. The arm unit 12 is arranged above the main body unit 7. The arm unit 13 is arranged above the arm unit 12. The hands 3 and 4 are arranged above the arm unit 13.

[0023] The arm 5 is extendable in both directions, in which the tip of the hand 3 approaches the main body 7 and in which the tip of the hand 3 moves away from the main body 7, and performs extension and contraction movements in the horizontal direction. The arm 5 also extends and contracts so that the hand 3 moves linearly while facing a fixed direction. Similarly, the arm 6 is extendable in both directions, in which the tip of the hand 4 approaches the main body 7 and in which the tip of the hand 4 moves away from the main body 7, and performs extension and contraction movements in the horizontal direction. The arm 6 also extends and contracts so that the hand 4 moves linearly while facing a fixed direction.

[0024] The robot 1 includes an arm drive mechanism that extends and retracts the arm 5 relative to the main body 7, an arm drive mechanism that extends and retracts the arm 6 relative to the main body 7, a rotation mechanism that rotates the main body 7 relative to the lifting unit 8, and an elevation mechanism that raises and lowers the lifting unit 8 relative to the holder 9. The robot 1 also includes a control unit 14 (see FIG. 5) for controlling the robot 1. When the arms 5 and 6 extend in a direction such that the tips of the hands 3 and 4 move away from the main body 7, the robot 1 places the wafer 2 loaded on the hands 3 and 4 in a wafer storage unit that stores the wafer 2. When the arms 5 and 6 extend in a direction such that the tips of the hands 3 and 4 move away from the main body 7, the robot 1 loads the wafer 2 stored in the wafer storage unit onto the hands 3 and 4.

[0025] (Hand Composition) Fig. 5 is a block diagram for explaining the configuration of the hands 3 and 4 shown in Fig. 1. Fig. 6 is a diagram for explaining a detection method for detecting whether or not a wafer 2 is mounted on the hand 4 shown in Fig. 1.

[0026] The hand 3 includes a mounting section 17 on which the wafer 2 can be mounted, a hand base 18 constituting the base end portion of the hand 3, and a rotation mechanism 19 that rotates the mounting section 17 by at least 180° relative to the hand base 18 with the horizontal direction as the axis of rotation. The hand base 18 is rotatably connected to the tip end of the arm section 13. In this embodiment, the mounting section 17 is a first mounting section, and the hand base 18 is a first hand base.

[0027] The mounting section 17 includes a mounting base end portion 20 that constitutes the base end portion of the mounting section 17, two linear mounting section bodies 21 on which the wafer 2 is mounted, two end face abutment members 22 having abutment surfaces 22a against which the end faces of the wafer 2 abut, two wafer placement members 23 fixed to the mounting section body 21, a pressing member 24 that presses the wafer 2 against the abutment surface 22a, and a moving mechanism 25 that moves the pressing member 24.

[0028] The mounting body 21 is formed in a flat plate shape. Furthermore, as described above, the mounting body 21 is formed in a linear shape. The base end of the mounting body 21 is fixed to the mounting base end portion 20, and the mounting body 21 extends horizontally from the mounting base end portion 20. The two mounting bodies 21 are arranged parallel to each other, spaced apart in a direction perpendicular to the longitudinal direction of the mounting body 21, and extend in the same direction. If the surface of the mounting part 17 on which the wafer 2 is mounted is designated as the mounting surface 17a, the wafer 2 is mounted on the mounting part 17 when the mounting surface 17a faces upward. When the mounting surface 17a faces upward or downward, the thickness direction of the flat mounting body 21 coincides with the vertical direction.

[0029] The end surface abutment members 22 are fixed to the tip end of the mounting body 21. The wafer placement members 23 are fixed to the base end side of the mounting body 21. Specifically, the end surface abutment members 22 are fixed to the surface of the tip end of the mounting body 21 that faces the mounting surface 17a, and the wafer placement members 23 are fixed to the surface of the base end side of the mounting body 21 that faces the mounting surface 17a. The wafer 2 is mounted on the two end surface abutment members 22 and the two wafer placement members 23.

[0030] The pressing member 24 includes two rollers 28 that contact the edge surface of the wafer 2 and a roller holding member 29 that rotatably holds the two rollers 28. The rollers 28 are attached to the tip of the roller holding member 29. The moving mechanism 25 includes an air cylinder 30 (see FIG. 4) that is arranged inside the mounting base end 20. The base end of the roller holding member 29 is connected to the air cylinder 30. The pressing member 24 and the air cylinder 30 are arranged at the center of the mounting unit 17 in a direction perpendicular to the longitudinal direction of the mounting unit main body 21. The air cylinder 30 moves the pressing member 24 linearly in the longitudinal direction of the mounting unit main body 21. The moving mechanism 25 is electrically connected to the control unit 14. Specifically, an electromagnetic valve or the like arranged in the piping path of the air cylinder 30 is electrically connected to the control unit 14.

[0031] The rotation mechanism 19 rotates the mounting unit 17 relative to the hand base 18 with the direction parallel to the longitudinal direction of the mounting unit main body 21 as the rotation axis direction. The rotation mechanism 19 is equipped with a motor 31. The motor 31 is attached to the hand base 18. The mounting base end 20 is connected to the output shaft of the motor 31. Specifically, the center of the mounting base end 20 in a direction perpendicular to the longitudinal direction of the mounting unit main body 21 is connected to the output shaft of the motor 31. The rotation mechanism 19 is electrically connected to the control unit 14. Specifically, the motor 31 and the like are electrically connected to the control unit 14. The rotation mechanism 19 rotates the mounting unit 17 relative to the hand base 18 in order to turn the wafer 2 mounted on the mounting unit 17 upside down.

[0032] The mounting part 17 is capable of holding the wafer 2 by two edge surface contact members 22 and two rollers 28 that come into contact with the edge surface of the wafer 2. That is, the mounting part 17 is capable of holding the mounted wafer 2. Therefore, even if the mounting part 17 is rotated relative to the hand base part 18 with the horizontal direction as the axial direction of the rotation, the wafer 2 will not fall off the mounting part 17.

[0033] The hand 4 includes a mounting section 37 on which the wafer 2 can be mounted, and a hand base 38 constituting the base end portion of the hand 4. The mounting section 37 is fixed to the hand base 38. The hand base 38 is rotatably connected to the tip end of the arm section 13. The mounting section 37 includes two linear mounting section bodies 41 on which the wafer 2 is mounted, two end face abutting members 42 having abutting surfaces 42a against which the end faces of the wafer 2 abut, and two wafer placement members 43 fixed to the mounting section bodies 41. The hand 4 also includes a pressing member 44 that presses the wafer 2 against the abutting surface 42a, a moving mechanism 45 that moves the pressing member 44, and three sensors 46 to 48 that detect the position of the pressing member 44. The mounting section 37 in this embodiment is a second mounting section.

[0034] The mounting body 41 is formed in the same manner as the mounting body 21. The base end of the mounting body 41 is fixed to the hand base 38, and the mounting body 41 extends horizontally from the hand base 38. The two mounting bodies 41 are arranged parallel to each other, spaced apart in a direction perpendicular to the longitudinal direction of the mounting body 41, and extend in the same direction. The mounting body 41 also extends in the same direction as the mounting body 21. The thickness direction of the flat-plate-shaped mounting body 41 coincides with the up-down direction. If the surface of the mounting part 37 on which the wafer 2 is mounted is defined as the mounting surface 37a, the mounting surface 37a faces upward.

[0035] The edge surface abutment member 42 is fixed to the upper surface of the tip end of the mounting body 41. The wafer placement member 43 is fixed to the upper surface of the base end side of the mounting body 41. The wafer 2 is placed on the two edge surface abutment members 42 and the two wafer placement members 43. The pressing member 44 has the same configuration as the pressing member 24, and includes two rollers 58 that contact the edge surface of the wafer 2, and a roller holding member 59 that rotatably holds the two rollers 58. A detection plate 61 (see FIGS. 6(D) to (F)) that is detected by the sensors 46 to 48 is fixed to the roller holding member 59. The detection plate 61 is disposed inside the hand base 38.

[0036] The moving mechanism 45 includes an air cylinder 60 (see FIG. 4) disposed inside the hand base 38. The base end of a roller holding member 59 is connected to the air cylinder 60. The pressing member 44 and the air cylinder 60 are disposed at the center of the hand 4 in a direction perpendicular to the longitudinal direction of the mounting body 41. The air cylinder 60 linearly moves the pressing member 44 in the longitudinal direction of the mounting body 41. The moving mechanism 45 is electrically connected to the control unit 14. Specifically, an electromagnetic valve or the like disposed in the piping path of the air cylinder 60 is electrically connected to the control unit 14. The hand 4 is capable of holding the wafer 2 by two edge surface abutment members 42 that contact the edge surface of the wafer 2 and two rollers 58.

[0037] The sensors 46 to 48 are, for example, transmission-type optical sensors having a light-emitting unit and a light-receiving unit arranged opposite each other. The sensors 46 to 48 are electrically connected to the control unit 14. The sensors 46 to 48 are arranged inside the hand base 38. The sensors 46 to 48 are arranged in the longitudinal direction of the mounting unit main body 41. The sensors 46 to 48 are also arranged in this order toward the tip end of the hand 4.

[0038] In this embodiment, as shown in Fig. 6(A), when the pressing member 44 is retracted so that the two rollers 58 are separated from the edge surface of the wafer 2 (i.e., when the pressing member 44 is moved toward the base end of the hand 4), the detection plate 61 blocks the light emitting portion and the light receiving portion of the sensor 46 as shown in Fig. 6(D). Also, at this time, the detection plate 61 does not block the light emitting portion and the light receiving portion of the sensor 47 and the light emitting portion and the light receiving portion of the sensor 48.

[0039] 6(B), when the pressing member 44 is moving forward so that the two rollers 58 come into contact with the edge surface of the wafer 2 with the wafer 2 mounted on the mounting portion 37 (i.e., when the pressing member 44 is moving toward the tip of the hand 4 in the direction of pressing the wafer 2 against the abutment surface 42a), the detection plate 61 blocks the light emitting portion and the light receiving portion of the sensor 47 as shown in FIG. 6(E). At this time, the detection plate 61 does not block the light emitting portion and the light receiving portion of the sensor 46 or the light emitting portion and the light receiving portion of the sensor 48.

[0040] 6(C), when the pressing member 44 is moving forward with no wafer 2 mounted on the mounting portion 37 (i.e., when the pressing member 44 is moving toward the tip end of the hand 4), the detection plate 61 blocks the light between the light-emitting portion and light-receiving portion of the sensor 47 and the light-emitting portion and light-receiving portion of the sensor 48, as shown in FIG. 6(F). In addition, at this time, the detection plate 61 does not block the light between the light-emitting portion and light-receiving portion of the sensor 46.

[0041] Therefore, in this embodiment, when the light-emitting portion and light-receiving portion of sensor 47 are blocked by detection plate 61 and sensor 47 is in the ON state, and when the light-emitting portion and light-receiving portion of sensor 48 are not blocked by detection plate 61 and sensor 48 is in the OFF state, it is detected that a wafer 2 is mounted on mounting portion 37, and when sensors 47 and 48 are both in the ON state, it is detected that a wafer 2 is not mounted on mounting portion 37. That is, in this embodiment, it is possible to detect whether or not a wafer 2 is mounted on mounting portion 37 based on the detection results of sensors 47 and 48.

[0042] In this embodiment, the sensors 47, 48 and the detection plate 61 constitute a detection mechanism 62 for detecting whether or not a wafer 2 is mounted on the mounting portion 37. That is, the hand 4 is provided with the detection mechanism 62. The detection mechanism 62 detects the position of the pressing member 44 when the pressing member 44 moves in the direction in which the wafer 2 is pressed against the contact surface 42a. The detection mechanism 62 also detects the position of the pressing member 44, thereby detecting whether or not a wafer 2 is mounted on the mounting portion 37.

[0043] The hand 3 also includes three sensors 66 to 68 for detecting the position of the pressing member 24. The sensors 66 to 68 are electrically connected to the control unit 14. A detection plate similar to the detection plate 61 is fixed to the roller holding member 29. Therefore, in this embodiment, it is also possible to detect whether or not a wafer 2 is mounted on the mounting unit 17.

[0044] The mounting portion 17 is disposed above the mounting portion 37. When the arm 5 and the arm 6 are in a predetermined standard state in which they are both retracted (see FIGS. 1 and 2), the mounting portions 17 and 37 overlap in the vertical direction. As shown in FIG. 3, the vertical distance between the rotation center of the mounting portion 17 relative to the hand base 18 and the upper surface of the mounting portion main body 41 is shorter than the radius of the wafer 2, which is formed in a disk shape. As described above, the mounting portion 37 is fixed to the hand base 38, and the mounting surface 37a of the mounting portion 37 faces upward. Therefore, in this embodiment, when the mounting portion 17 holding the wafer 2 rotates relative to the hand base 18, the mounting portion 37 stops with the mounting surface 37a facing upward.

[0045] (Robot operation when flipping wafer) The robot 1, for example, uses the hand 3 to turn upside down the wafer 2 that has been carried out from one wafer storage unit, and then carries the wafer 2 into another wafer storage unit. When turning upside down the wafer 2, when the detection mechanism 62 detects that the wafer 2 is not mounted on the mounting unit 37 while the wafer 2 is mounted and held on the mounting unit 17 (i.e., when the detection plate 61 blocks the light between the light-emitting part and the light-receiving part of the sensor 47, and the light-emitting part and the light-receiving part of the sensor 48), the control unit 14 activates the rotation mechanism 19 to rotate the mounting unit 17 and turn upside down the wafer 2 held by the mounting unit 17.

[0046] Specifically, when the arms 5 and 6 are in the retracted reference state (see FIGS. 1 and 2), and the detection mechanism 62 detects that the wafer 2 is not mounted on the mounting portion 37 while the wafer 2 is mounted and held on the mounting portion 17, the control unit 14 rotates the mounting portion 17 to turn upside down the wafer 2 held by the mounting portion 17. On the other hand, when the detection mechanism 62 detects that the wafer 2 is mounted on the mounting portion 37 while the wafer 2 is mounted and held on the mounting portion 17 (i.e., when only the light emitting portion and the light receiving portion of the sensor 47 are blocked by the detection plate 61), the control unit 14 does not rotate the mounting portion 17.

[0047] In the process of turning the wafer 2 held by the mounting part 17 upside down, the lower end of the wafer 2 held by the mounting part 17 is temporarily positioned between the two mounting part bodies 41. In this embodiment, the distance between the two mounting part bodies 41 is set so that the mounting part bodies 41 and the wafer 2 do not interfere with each other when the wafer 2 held by the mounting part 17 is turned upside down, and the distance between the two mounting part bodies 41 is relatively wide.

[0048] (Main effect of this form) As described above, in this embodiment, the hand 4 is provided with the detection mechanism 62 for detecting whether or not the wafer 2 is mounted on the mounting portion 37. Furthermore, in this embodiment, when the detection mechanism 62 detects that the wafer 2 is not mounted on the mounting portion 37, the control unit 14 rotates the mounting portion 17 to turn the wafer 2 held by the mounting portion 17 upside down.

[0049] Therefore, in this embodiment, even if the distance between the mounting portion 17 and the mounting portion 37 in the vertical direction is narrowed, when the mounting portion 17 holding the wafer 2 rotates about the horizontal direction as the axis of rotation with the mounting portion 17 and the mounting portion 37 overlapping each other in the vertical direction, the wafer 2 mounted on the mounting portion 37 and the wafer 2 held by the mounting portion 17 do not interfere with each other. That is, in this embodiment, even if the mounting portion 17 holding the wafer 2 rotates about the horizontal direction as the axis of rotation with the mounting portion 17 and the mounting portion 37 overlapping each other in the vertical direction, it is possible to narrow the distance between the mounting portion 17 and the mounting portion 37 in the vertical direction while preventing interference between the wafer 2 mounted on the mounting portion 37 and the wafer 2 held by the mounting portion 17.

[0050] In this embodiment, the detection mechanism 62 detects the position of the pressing member 44 when the pressing member 44 moves in the direction in which the wafer 2 is pressed against the contact surface 42a of the end surface contact member 42, and by detecting the position of the pressing member 44, it is possible to detect whether or not the wafer 2 is loaded on the loading section 37. That is, in this embodiment, the pressing member 44 that presses the wafer 2 against the contact surface 42a is used to detect whether or not the wafer 2 is loaded on the loading section 37. Therefore, in this embodiment, it is possible to simplify the configuration of the hand 4.

[0051] (Other embodiments) The above-described embodiment is one example of a preferred embodiment of the present invention, but the present invention is not limited to this embodiment and various modifications can be made without departing from the spirit of the present invention.

[0052] In the embodiment described above, the hand 4 does not need to include the sensor 48. In this case, for example, when the pressing member 44 advances so that the two rollers 58 come into contact with the edge surface of the wafer 2 with the wafer 2 mounted on the mounting portion 37 (see FIG. 6(B)), the detection plate 61 is formed and the sensors 46, 47 are arranged so that the detection plate 61 blocks the gap between the light-emitting portion and light-receiving portion of the sensor 46 and the gap between the light-emitting portion and light-receiving portion of the sensor 47.

[0053] Furthermore, when the pressing member 44 is moving forward with no wafer 2 loaded on the loading section 37 (see FIG. 6(C)), the detection plate 61 is formed and the sensors 46, 47 are arranged so that the light-emitting section and the light-receiving section of the sensor 47 are blocked by the detection plate 61, and the light-emitting section and the light-receiving section of the sensor 46 are not blocked by the detection plate 61. In this case, the sensors 46, 47 and the detection plate 61 constitute a detection mechanism 62, and it becomes possible to detect whether or not the wafer 2 is loaded on the loading section 37 based on the detection results of the sensors 46, 47.

[0054] In the above-described embodiment, the detection mechanism 62 may be provided with, for example, a reflective optical sensor or a non-optical sensor instead of the sensors 47 and 48, which are transmissive optical sensors. Furthermore, in the above-described embodiment, the pressing member 44 is used to indirectly detect whether or not the wafer 2 is mounted on the mounting portion 37, but the pressing member 44 does not have to be used to detect whether or not the wafer 2 is mounted on the mounting portion 37. For example, a sensor disposed on the upper surface of the mounting portion main body 41 may directly detect whether or not the wafer 2 is mounted on the mounting portion 37.

[0055] In the above-described embodiment, the mounting portion 37 may be rotatable relative to the hand base 38 with the horizontal direction as the axial direction of the rotation. In this case, the hand 4 is provided with a rotation mechanism that rotates the mounting portion 37 by at least 180° relative to the hand base 38 with the horizontal direction as the axial direction of the rotation. In this case, the pressing member 44 and the moving mechanism 45 are attached to the mounting portion 37. The hand 3 is also provided with a detection mechanism for detecting whether or not a wafer 2 is mounted on the mounting portion 37.

[0056] If the mounting portion 37 is rotatable relative to the hand base 38 with the horizontal direction as the axis of rotation, the mounting portion 17 may be fixed to the hand base 18 (i.e., the mounting portion 17 does not have to be rotatable relative to the hand base 18), or, as in the above-described embodiment, the mounting portion 17 may be rotatable relative to the hand base 18 with the horizontal direction as the axis of rotation.

[0057] In the case where mounting portion 37 is rotatable and mounting portion 17 is fixed, when the detection mechanism of hand 3 detects that wafer 2 is not mounted on mounting portion 17 while wafer 2 is mounted and held on mounting portion 37, control portion 14 rotates mounting portion 37 to turn upside down the wafer 2 held by mounting portion 37. In this case, hand 3 becomes the second hand, hand 4 becomes the first hand, mounting portion 17 becomes the second mounting portion, mounting portion 37 becomes the first mounting portion, and hand base 38 becomes the first hand base. In this case, mounting portion 17, which is the second mounting portion, is disposed above mounting portion 37, which is the first mounting portion.

[0058] Furthermore, in the case where the mounting portion 37 is rotatable and the mounting portion 17 is also rotatable, when the mounting portion 17 holding the wafer 2 rotates relative to the hand base 18, the mounting portion 37 stops with the mounting surface 37a facing upward or downward. In this case, when the mounting portion 37 holding the wafer 2 rotates relative to the hand base 38, the mounting portion 17 stops with the mounting surface 17a facing upward or downward.

[0059] In this case, when the detection mechanism 62 detects that the wafer 2 is not loaded on the mounting portion 37 while the wafer 2 is loaded and held on the mounting portion 17, the control unit 14 rotates the mounting portion 17 to invert the wafer 2 held by the mounting portion 17 upside down, and when the detection mechanism of the hand 3 detects that the wafer 2 is not loaded on the mounting portion 17 while the wafer 2 is loaded and held on the mounting portion 37, the control unit 14 rotates the mounting portion 37 to invert the wafer 2 held by the mounting portion 37 upside down.

[0060] When the mounting unit 17 holding the wafer 2 rotates relative to the hand base 18 while the mounting unit 37 is stopped with the mounting surface 37a facing upward or downward, the hand 3 becomes the first hand, the hand 4 becomes the second hand, the mounting unit 17 becomes the first mounting unit, the hand base 18 becomes the first hand base, and the mounting unit 37 becomes the second mounting unit. On the other hand, when the mounting unit 17 holding the wafer 2 rotates relative to the hand base 38 while the mounting unit 17 is stopped with the mounting surface 17a facing upward or downward, the hand 3 becomes the second hand, the hand 4 becomes the first hand, the mounting unit 17 becomes the second mounting unit, the mounting unit 37 becomes the first mounting unit, and the hand base 38 becomes the first hand base.

[0061] In the above-described embodiment, the arms 5 and 6 may be configured with three or more arm portions rotatably connected to each other. Furthermore, in the above-described embodiment, the robot 1 may be provided with an arm that holds the hands 3 and 4 so that the hands 3 and 4 can slide linearly in the horizontal direction, instead of the arms 5 and 6 that are articulated arms. Furthermore, in the above-described embodiment, the robot 1 may transport an object other than the wafer 2. [Explanation of symbols]

[0062] 1. Robots (industrial robots) 2. Wafers (semiconductor wafers, transported objects) 3rd Hand (1st Hand) 4th hand (2nd hand) 5 Arm (1st Arm) 6 Arm (2nd Arm) 7 Main body 14 Control Unit 17 Mounting section (first mounting section) 18 Hand base (first hand base) 19 Rotating mechanism 21 Mounting unit main body 37 Mounting section (second mounting section) 37a Mounting surface 41 Mounting unit main body 42 End face abutment member 42a Contact surface 44 Pressing member 45 Moving mechanism 62 Detection mechanism

Claims

1. An industrial robot for transporting an object to be transported, a first hand and a second hand on which the object to be transported is placed, and a control unit for controlling the industrial robot; the first hand includes a first mounting portion on which the transport object can be mounted and which can hold the mounted transport object, a first hand base portion which constitutes a base end side portion of the first hand, and a rotation mechanism which rotates the first mounting portion by at least 180° relative to the first hand base portion with the horizontal direction as an axial direction of rotation, the second hand includes a second mounting portion on which the object to be transported can be mounted, and a detection mechanism for detecting whether the object to be transported is mounted on the second mounting portion; one of the first mounting portion and the second mounting portion is disposed above the other of the first mounting portion and the second mounting portion, When the surface of the second mounting portion on which the object to be transported is mounted is defined as a mounting surface, when the first mounting unit that holds the transport object rotates with respect to the first hand base, the second mounting unit is stopped with the mounting surface facing upward or downward; When the detection mechanism detects that the transport object is not mounted on the second mounting portion, the control unit rotates the first mounting portion to turn the transport object held by the first mounting portion upside down.

2. a first arm to which the first hand is rotatably connected at a tip end thereof, a second arm to which the second hand is rotatably connected at a tip end thereof, and a main body to which a base end side of the first arm and a base end side of the second arm are rotatably connected, the first hand is rotatable relative to the first arm with the vertical direction as the axis of rotation, the second hand is rotatable relative to the second arm with the vertical direction as the axis of rotation, the first arm and the second arm are rotatable relative to the main body with the vertical direction as an axial direction of rotation, the first arm is extendable in a direction in which a tip of the first hand approaches the main body and in a direction in which the tip of the first hand moves away from the main body, the second arm is extendable in a direction in which a tip of the second hand approaches the main body and in a direction in which the tip of the second hand moves away from the main body, When the first arm and the second arm are in a predetermined reference state in which they are retracted, the first mounting portion and the second mounting portion are overlapped in the vertical direction, 2. The industrial robot according to claim 1, wherein when the detection mechanism detects that the transport object is not mounted on the second mounting portion while the control unit is in the reference state, the control unit rotates the first mounting portion to turn the transport object held by the first mounting portion upside down.

3. The object to be conveyed is formed in a disk shape, the first mounting portion and the second mounting portion each include two linear mounting portion bodies on which the object to be transported is mounted, 3. The industrial robot according to claim 1, wherein the two mounting body parts are arranged parallel to each other and spaced apart in a direction perpendicular to the longitudinal direction of the mounting body parts.

4. the second mounting portion includes an end surface contact member having a contact surface with which an end surface of the object to be conveyed comes into contact, the second hand includes a pressing member that presses the object to be transported toward the contact surface, and a movement mechanism that moves the pressing member; 4. The industrial robot according to claim 1, wherein the detection mechanism detects a position of the pressing member when the pressing member moves in a direction in which the object to be transported is pressed against the contact surface.

5. a first hand and a second hand on which an object to be transported is placed; the first hand includes a first mounting portion on which the transport object can be mounted and which can hold the mounted transport object, a first hand base portion which constitutes a base end side portion of the first hand, and a rotation mechanism which rotates the first mounting portion by at least 180° relative to the first hand base portion with the horizontal direction as an axial direction of rotation, the second hand includes a second mounting portion on which the object to be transported can be mounted, and a detection mechanism for detecting whether the object to be transported is mounted on the second mounting portion; one of the first mounting portion and the second mounting portion is disposed above the other of the first mounting portion and the second mounting portion, When the surface of the second mounting portion on which the object to be transported is mounted is defined as a mounting surface, a control method for an industrial robot, wherein when the first mounting unit that holds the transport object rotates with respect to the first hand base, the second mounting unit is stopped with the mounting surface facing upward or downward, A control method for an industrial robot, characterized in that when the detection mechanism detects that the transport object is not loaded on the second loading section, the first loading section is rotated to turn the transport object held by the first loading section upside down.

Images