Terminal effector and robot with same

Abstract

Described herein is an end effector adapted to carry wafers as well as wafer cassettes. The end effector is provided with a first grabbing unit which is configured to accommodate and hold a single wafer; the first grabbing unit is configured to hold a wafer box, the second grabbing unit is configured to hold and hold the wafer box, and the first grabbing unit and the second grabbing unit are connected, so that the first grabbing unit and the second grabbing unit can be fastened on a common machine arm and form a certain angle, and the first grabbing unit and the second grabbing unit do not interfere with each other in the working process.

Description

[0001] This invention relates to a terminal effector for use in the semiconductor or photovoltaic industries and a robot having a terminal effector.

[0002] In the semiconductor or photovoltaic industries, wafers are typically processed in cleanrooms or dry rooms (hereinafter referred to as cleanrooms). These processes include individual processes and batch processes. These processes can be performed continuously or with time delays. Between time-delayed processes, wafers are typically housed in so-called wafer cassettes, where different types and sizes of wafer cassettes are used. Wafers and wafer cassettes are usually handled by robots, with dedicated robots for each type of wafer and wafer cassette, each having its own, but generally limited, floor space requirement.

[0003] Wafer robots have termination effectors for accommodating and holding one or more wafers for transporting and returning (as needed, returning to another wafer cassette) between wafer cassettes and process stations. Wafer robots can also transport accommodated wafers directly between process stations, depending on the situation. When transporting from / to a wafer cassette, it is typically located at a designated loading and / or unloading position. Wafers are generally always transported from / to the same position, simplifying wafer robot control. Wafer cassettes are transported, for example, from a gate to the loading and / or unloading position by a designated cassette robot. Termination effectors may need to be changed to transport wafer cassettes of different types and / or sizes. Furthermore, the working paths of the two robots partially intersect, requiring coordination to avoid collisions. Additionally, each robot must learn individually for the environment and the corresponding transport position. Cartridge handling is particularly important in environments with internal memory within the wafer cassette.

[0004] The object of this invention is to overcome at least one of the above-mentioned disadvantages, or to propose at least one improvement. The solutions of this invention to achieve the above object are the terminal effector as claimed in claim 1 and the robot as claimed in claim 8.

[0005] Specifically, an end effector is provided, comprising a first gripping unit configured to hold and hold a single wafer, and a second gripping unit configured to hold and hold a wafer cassette. The first and second gripping units are connected and secured to a common robotic arm at an angle to each other to prevent interference during operation. This end effector allows a single robot to transport both wafers and wafer cassettes without requiring replacement of the end effector. This reduces the footprint and hardware required for handling, thereby lowering handling costs. It also reduces potential sources of particles and errors by minimizing moving parts, making it particularly advantageous for cleanroom applications. Furthermore, it simplifies robot learning due to the shared origin and the fact that certain starting positions (wafer cassette / wafer receiving / wafer storage) are at least partially consistent.

[0006] In one embodiment, the first and second gripping units are at approximately 180° angles to each other, wherein the central axes of the gripping units are considered to be offset by 180° from each other.

[0007] Preferably, the first and second gripping units are connected via a coupling unit, wherein the coupling unit can be connected to the common robotic arm, such that the coupling unit is connected to at least one connection port of the working medium, preferably the same connection port, to the respective gripping unit to actuate the gripping unit. The robotic arm may, for example, have connection ports for compressed air, negative pressure, and / or electricity to control the gripping units. Preferably, the same connection port can be used to control both the first and second gripping units, wherein switching between operating the first and second gripping units is possible. The end effector may have a rotating unit, by which the end effector is mounted on the robotic arm in a manner that preferably allows it to rotate back and forth between at least two positions, wherein the position of the end effector determines the ready-to-use state of the first or second gripping unit. This rotation may also, for example, allow the working medium to be connected only to the available gripping unit. Reciprocating rotation can simplify the structure, as end stops can be used. Alternatively, the terminal effector can be rigidly mounted on the robotic arm, and the corresponding gripping unit can be positioned solely by the movement of the robotic arm.

[0008] Preferably, the first gripping unit is configured as a vacuum gripper, a Bernoulli gripper, or an edge gripper. The first gripping unit can be configured as a single gripper for accommodating a single wafer or as a multi-gripper for accommodating multiple wafers.

[0009] In one embodiment, the second gripping unit has movable jaws, the profile of which is preferably designed such that the jaws can accommodate at least two different cassette sizes or types while maintaining the same movement path. This eliminates the need to change the terminal effector when handling wafer cassettes of different types / sizes. Furthermore, the same movement can be used during the learning process of the terminal effector, so handling can be performed even without knowledge of the cassette type or size. For this purpose, the profile may, for example, have abutment or gripping surfaces and / or bearing surfaces offset in the (opening / closing) movement direction of the jaws, which interact with the wafer cassette. In particular, the jaws may have two bearing surfaces located on different planes, which are also offset from each other in the movement direction of the jaws.

[0010] The movable gripper can be adjusted, for example, by a cylinder unit that can operate with compressed air and / or negative pressure, wherein the gripper can be mechanically pre-tightened to a gripping position to prevent the gripper from accidentally opening, for example, when the working medium fails.

[0011] A robot having a drive system with at least one robotic arm, the robotic arm carrying an end effector as claimed in any of the preceding claims at its free end.

[0012] The present invention will now be described in detail with reference to the accompanying drawings, wherein...

[0013] Figure 1 A schematic top view of an exemplary wafer fabrication apparatus having a robot with the terminal effector of the present invention;

[0014] Figure 2 A schematic perspective view of a robot having the terminal effector of the present invention;

[0015] Figure 3 This is a perspective view of the terminal effector of the present invention;

[0016] Figure 4 This is a perspective top view of the terminal effector of the present invention;

[0017] Figure 5 A perspective view of the gripper claw when gripping a type 1 wafer cassette;

[0018] Figure 6 When grabbing the second type of wafer cassette Figure 5 Perspective view of the gripper shown;

[0019] Figure 7 and 8 Perspective view of alternative terminal effectors in different working positions.

[0020] The relative terms used below, such as left, right, top, and bottom, refer to the accompanying drawings and, even if they indicate preferred arrangements, do not constitute any limitation on this application. The term "substantially" includes a common deviation of no more than 5%, and when angular ranges are involved, it includes a deviation of a maximum of 2°.

[0021] Figure 1 This is a schematic top view of an exemplary wafer fabrication equipment 1, which includes a housing 3, two gate units 4 and 5, a process unit 7, a cassette housing unit 9 and 10, and a robot 12 with a terminal effector 13.

[0022] The housing 3 of the exemplary wafer fabrication equipment 1 has a rectangular base with two longitudinal sides and two transverse sides. The housing is constructed to provide a cleanroom atmosphere internally, through which the wafer fabrication equipment 1 itself can also be placed. Two gates 4 and 5 are mounted on one of the transverse sides, through which wafer cassettes can be fed into and out of the housing, as disclosed in the prior art. In this embodiment, wafer cassettes for unprocessed and processed wafers are distinguished. Wafer cassettes for unprocessed wafers are, for example, of the type used for long-term housing and storage of wafers, while wafer cassettes for processed wafers are essentially purely transport cassettes, as they are used to transport wafers directly to the next process. Wafer cassettes for unprocessed wafers are fed in / out via gate 4, for example, while wafer cassettes for processed wafers are fed in / out via gate 5. Feeding and output can also be performed via both gates. These wafer cassettes can have different sizes, which will be described in detail below. As an alternative to the two gates 4 and 5, two or more gate units or a single gate unit may be provided for feeding and / or feeding out, as disclosed in the prior art. A single wafer cell may also be used.

[0023] A process unit 7 is located inside the housing 3, in which wafers can be processed individually or in batches. Various process units are well-known in the art and need not be described in detail. In the illustrated embodiment, the process unit 7 is arranged adjacent to the gate units 4 and 5 on their lateral sides. Other arrangements in the prior art, as known to those skilled in the art, may also be used.

[0024] Two cassette receiving units 9 and 10 are provided adjacent to the process unit 7 and between the process unit 7 and the lateral side having gate units 4 and 5. Wafer cassettes can be housed in defined positions on the cassette receiving units in an existing manner. The cassette receiving units 9 and 10 are adjacent to the longitudinal side of the housing 3, i.e., spaced a certain distance laterally. In this embodiment, for example, cassettes fed in via gate 4 can be housed in cassette receiving unit 9, while cassettes fed in via gate 5 can be housed in cassette receiving unit 10. Correspondingly, feeding is performed in the opposite manner, i.e., feeding is performed from cassette receiving unit 9 via gate 4 and from cassette receiving unit 10 via gate 5. The corresponding movement paths are indicated by dashed lines A and B in the figure.

[0025] A robot 12 with an end effector 13 is provided between the process unit and the gate unit. As shown in the figure, the robot 12 has a base 15, three rotating axes 17, 18, 19, two arms 22, 23, and the aforementioned end effector 13.

[0026] The base 15 is fixedly connected to the ground and contains control electronics for the robot. The base 15 can also be movable, allowing the control electronics to be externally mounted. The base supports the rotating shaft 17 such that the rotating shaft 17 can rotate about its axis and also displace along its axis. Therefore, the rotating shaft 17 is constructed as a lifting / rotating shaft. At its free end (away from the base 15), the rotating shaft 17 supports a first arm 22, which is torsionally secured to the rotating shaft 17 and thus rotates together with it about the axis of the rotating shaft 17. The first arm 22 is an elongated support element that is substantially perpendicular to the axis of rotation of the rotating shaft 17, as disclosed in the prior art.

[0027] A first arm carries another rotating shaft 18 at its free end (remote of the rotating shaft 17), which is substantially perpendicular to the first arm and has a rotation axis substantially parallel to the rotation axis of the rotating shaft 17. The first arm has a drive mechanism for the rotating shaft 18, or the first arm may be integrated into the rotating shaft 18. At the free end of the rotating shaft 18 (remote of the first arm 22), the rotating shaft carries a second arm 23, which is torsionally secured to the rotating shaft 18 and thus rotates together with it about the axis of the rotating shaft 18. The second arm 23 is an elongated support element that is substantially perpendicular to the rotation axis of the rotating shaft 18, as disclosed in the prior art.

[0028] The second arm 23 carries another rotating shaft 19 at its free end (remote of the rotating shaft 18), which is substantially perpendicular to the second arm 23 and has a rotation axis substantially parallel to the rotation axis of the rotating shaft 18. The second arm 23 has a drive mechanism for the rotating shaft 19, or the second arm may be integrated into the rotating shaft 19. At the free end of the rotating shaft 19 (remote of the second arm 23), the rotating shaft carries an end effector 13, which is fastened to the rotating shaft 19 such that the end effector rotates together with the rotating shaft about the axis of the rotating shaft 19. The rotating shafts 17, 18, and 19 may all be implemented as hollow shafts, wherein control wires and / or conduits for the working medium of the end effector may extend within the shaft body. Other arrangements for robots have also been disclosed in the prior art, in which the corresponding arms, for example, have rotational drive mechanisms for rotation about the axis of the shaft implemented as a stationary shaft. Such arrangements are also possible with the present invention. These drive mechanisms and movable segments form a drive system for a robot, which enables the movement and positioning of the end effector.

[0029] Figures 2 to 4The terminal effector 13, clearly shown in the image, has a central coupling unit 25, and a first gripping unit 27 and a second gripping unit 28 extending from the central coupling unit 25. The central coupling unit 25 is fixedly connected to the rotating shaft 19 and has at least one connection port for controlling the wires and / or the working medium, so as to control the first and second gripping units.

[0030] The second gripping unit 27 is configured as a wafer gripper and is used to transport wafers W between wafer cassettes and process cells and / or (if there is more than one process cell) between process cells. In the illustrated embodiment, the first gripping unit 27 is used, for example, to transport wafers (along the illustrated path A) from wafer cassettes on cassette accommodating portion 9 to process cells 7, and (along the illustrated path B) from process cells 7 to wafer cassettes on cassette accommodating portion 10. The first gripping unit 27 has, in a conventional manner, an elongated carrier 30 and a accommodating unit 31.

[0031] The carrier 30 is rigidly connected to the coupling unit 25 and carries the housing unit 31 on its free end. The carrier extends along a longitudinal axis L that is centered in the transverse direction, which preferably intersects with and is perpendicular to the axis of rotation of the rotating shaft 19. A pipeline for the working medium is provided in or on the carrier 30, which is coupled to the coupling unit 25 through corresponding connection ports.

[0032] The receiving unit 31 is located at the free end of the carrier 30 and is composed of a generally C-shaped receiving portion that is substantially symmetrical with respect to the longitudinal axis L. The receiving unit 31 is preferably integrally formed with the carrier 30, but can also be constructed as a separate component. At the endpoints and apex of the C-shape, for example, upward-pointing openings surrounded by a bearing flange may be provided. These openings are connected to conduits for a working medium to apply to the upper wafer W, thereby holding the wafer in a defined manner. For example, negative pressure can be applied through the openings to pull the wafer W toward the bearing flange, thereby holding and securing it. Compressed air can also be applied in a controlled manner to suspend and hold the wafer W by the Bernoulli effect. Alternatively, the receiving unit may also be constructed as a so-called edge gripper, which grips or holds the wafer with its edge, thereby reliably holding and securing it. Such grippers and alternatives have been disclosed in the prior art and will not be described further.

[0033] The first gripping unit may additionally have an alignment sensor and / or a wafer rotation unit, see existing solutions.

[0034] The embodiment shown depicts a single first gripping unit 27 configured as a wafer gripper. Multiple such first gripping units 27 may also be stacked to simultaneously accommodate multiple wafers W. For example, when the distance between wafers W housed in a wafer cassette and the distance between wafers W housed in a process chamber are the same, these gripping units may have a fixed height spacing. Alternatively, for example, when the distance between wafers W housed in a wafer cassette and the distance between wafers W housed in a process chamber are different, the height spacing may also be adjustable.

[0035] The second gripping unit 28 is configured as a cassette gripper and is used to transport wafer cassettes between gates 4 and 5 and cassette receiving portions 9 and 10. In the illustrated embodiment, the second gripping unit 28 is used, for example, to transport wafer cassettes (along the illustrated path C) from gate 4 to cassette receiving portion 9 and back, and to transport wafer cassettes (along the illustrated path D) from gate 5 to cassette receiving portion 10 and back. The second gripping unit 28 is mounted on the coupling unit 25 at the end opposite to the first gripping unit 27. The longitudinal axis L of the first gripping unit 27 also substantially forms the transversely centered longitudinal axis of the second gripping unit 28. With the terminal effector 13 installed, the axis of rotation of the rotating shaft 19 is substantially located at the center of the first and second gripping units 27 and 28.

[0036] The second gripping unit 28 has an operating unit 40 and two gripping claws 42 connected to the operating unit 40. The operating unit 40 is mounted on the coupling unit 25 at the end opposite to the first gripping unit 27. The operating unit 40 is mounted on the coupling unit 25 and is substantially composed of a cylinder unit 44 having opposing movable cylinders. The cylinder unit extends transversely to the longitudinal axis L and is symmetrical with respect to the longitudinal axis, such that when the cylinder of the cylinder unit moves, its end moves substantially symmetrically with respect to the plane formed by the longitudinal axis L and the axis of rotation of the rotating shaft 19. During extension, the free end of the cylinder moves uniformly away from the plane, and during retraction, it moves uniformly towards the plane. The cylinder unit is connected to a working medium, such as compressed air, negative pressure, and / or electrical power, via the coupling unit, which controls the extension and retraction of the cylinder of the cylinder unit in the aforementioned manner. The retraction and extension positions of the cylinder unit can be limited by a stop and can be determined by a suitable decoder. The cylinder can be mechanically preloaded to the retracted position by a spring, for example, so that the working medium must move the cylinder in the opposite direction of the preload force, and the cylinder automatically returns to the retracted position, i.e. the gripping position, when there is no working medium, which will be described in detail below.

[0037] The control unit 40 and the coupling unit 25 can be covered by a common housing 45, see reference. Figures 2 to 4 .

[0038] A gripping claw 42 is mounted on the free end of each cylinder of cylinder unit 44, extending substantially parallel to the longitudinal axis L away from coupling unit 25. The gripping claws are rigidly mounted on the cylinders and move with them. As the cylinders extend, the gripping claws separate symmetrically with respect to the aforementioned plane; when the cylinders retract, the gripping claws move symmetrically toward each other to the gripping position, as those skilled in the art will understand. The gripping claws 42 are substantially symmetrical with respect to the plane formed by the longitudinal axis L and the axis of rotation of the rotating shaft 19. The gripping claws have a certain profile on their opposing sides to accommodate and grip wafer cassettes. The profile of the gripping claws 42 matches the profile of the wafer cassette to be gripped. In particular, the profile can be selected such that it can accommodate and grip two different (type / size) wafer cassettes within the same cylinder stroke.

[0039] In the illustrated embodiment, this is achieved as follows: the gripper 42 has two height-offset bearing surfaces 48 and 49 and abutment surface 50. The bearing surfaces 48 and 49 extend substantially horizontally and are parallel to the direction of movement of the cylinders in the cylinder unit 44. The abutment surface 50 extends substantially vertically, i.e., perpendicular to the bearing surfaces. The bearing surface 48 is arranged above the abutment surface 50 and extends rearward from the abutment surface immediately adjacent to it. The bearing surface 49 is arranged below the abutment surface 50 and extends forward immediately adjacent to it.

[0040] The wafer cassette to be accommodated has a corresponding profile to interact with the wafer gripper and the corresponding bearing and abutment surfaces, which will be discussed below. Figure 5 and 6 A detailed description is provided. The figure shows the engagement of the gripper 42 with wafer cassettes 60, 60', which may be of different types or sizes. Wafer cassettes 60, 60' have recessed regions 61, 61' extending longitudinally (perpendicular to the loading / unloading port) at their lower ends, forming a lateral edge 64, 64' and a downward edge 65, 65', respectively. The recessed regions 61, 61' are constructed relative to the sidewalls of wafer cassettes 60, 60', which substantially define the width of wafer cassettes 60, 60'. On the inner side of the sidewalls, above the recessed regions 61, 61', a support portion for accommodating the wafer is arranged. Therefore, the distance between the sidewalls also defines the accommodating size.

[0041] Wafer box 60 ( Figure 5 The external distance between the sidewalls of ) is different from that of wafer cell 60'. Figure 6 The external distance between the sidewalls of the wafer cell 60. Specifically, the distance between the sidewalls of the wafer cell 60. Figure 5 The external distance between the sidewalls of the wafer cell is less than 60'. Figure 6The external distance between the sidewalls of the wafer cassette 60' is approximately equal to the external distance between the sidewalls of the wafer cassette 60. Thus, the abutment surface 50 of the wafer gripper 42 can engage either with the sidewall of the wafer cassette 60 or with the side-pointing edge 64' when the travel is the same. (See [reference]). Figure 5 and 6 .

[0042] use Figure 5 When the wafer cassette 60 is shown, the lower bearing surface 49 of the wafer gripper, which extends forward relative to the abutment surface 50, can move and contact the downward-pointing edge 65 of the recessed area 61 when the wafer gripper is lifted, thereby reliably accommodating and holding the wafer cassette. Figure 6 When the wafer cassette 60' is shown, the upper bearing surface 48 of the wafer gripper, which extends rearward relative to the abutment surface 50, is movable during wafer gripper lifting and contacts the downward-pointing edge 65' of the recessed area 61', thereby reliably accommodating and holding the wafer cassette. In this case, the downward-pointing edges 65, 65' are particularly suitable for contacting the corresponding bearing surfaces 48, 49, because these edges are typically freely accessible (not used as mounting surfaces) and employ a defined structure.

[0043] That is, the gripper has a certain profile, enabling it to accommodate different wafer cassettes (with corresponding profiles) when the stroke is the same. Of course, other configuration schemes can also be used as an alternative to the configuration scheme shown, which depends on the wafer cassettes on site.

[0044] Combination Figure 7 and 8 An alternative embodiment of the terminal effector 13 is described, wherein the same or similar elements are represented by the same element symbols previously used. The terminal effector 13 also has a central coupling unit 25, and a first gripping unit 27 and a second gripping unit 28 extending from the central coupling unit 25. The central coupling unit 25 and the first gripping unit 27 are substantially equivalent to the first embodiment, and therefore need not be described further.

[0045] The second gripping unit 28 also includes a manipulation unit 40 and two gripping claws 42 connected to the manipulation unit 40. The structure of the manipulation unit 40 is substantially the same as that of the first embodiment.

[0046] The main difference from the first embodiment lies in the gripper 42. The gripper 42 of the first embodiment has a substantially horizontal orientation and, in particular, a horizontal bearing surface, while... Figure 7 , 8 The gripper 42 shown has a substantially vertical orientation.

[0047] Figure 7 , 8The gripper claw 42 is specifically configured to grip the vertically extending flange of the wafer cassette 60''. This flange extends, for example, at the height of the positive side of the wafer cassette 60'' (towards the loading / unloading port) and extends outwards relative to the loading / unloading port. Such flanges are partially already installed in the field wafer cassette. The wafer cassette 60'' can be gripped by corresponding engagement with the flange. As an additional auxiliary measure, a horizontal bearing portion can also be provided on the gripper claw, in conjunction with... Figure 5 Similar to the embodiment shown in 6, these carriers can engage with the bottom side of the wafer cassette 60'' or with the downward-pointing abutment surface.

[0048] The present invention has been described in detail above with reference to the embodiments shown in the accompanying drawings, but the present invention is not limited to these specific embodiments. In particular, regarding the specific embodiments of the first and second gripping units of the terminal effector, those skilled in the art can derive different embodiments based on the principles of the present invention.

Claims

1. A terminal effector having: a first gripping unit configured to receive and hold a single wafer; A second gripping unit is configured to receive and hold a wafer box, wherein the first and second gripping units are connected so that they can be fastened to a common robot arm and are at a certain angle to each other so that they do not interfere with each other during operation.

2. The end effector of claim 1, wherein the first and second gripping units are at an angle of approximately 180° to each other.

3. The terminal effector according to claim 1 or 2, wherein the first and second gripping units are connected via a coupling unit, wherein the coupling unit can be connected to the common robot arm, so that the coupling unit connects at least one connection port for the working medium, preferably the same connection port, to the corresponding gripping unit to actuate the gripping unit.

4. The end effector according to any of the preceding claims, further comprising a rotation unit, by means of which the end effector is mounted on the robot arm in such a way that it can be rotated back and forth between at least two positions, wherein the position of the end effector determines the readiness for use of the first or second gripping unit. 5 . The end effector according to claim 1 , wherein the first gripping unit is designed as a vacuum gripper, a Bernoulli gripper or an edge gripper.

6. The end effector according to any of the preceding claims, wherein the second gripping unit has a movable jaw, wherein the jaw is contoured such that it can accommodate at least two different box sizes or box types with the same travel path.

7. The end effector according to claim 6, wherein the movable jaw is adjusted by a cylinder unit, wherein the jaw is mechanically preloaded into a gripping position.

8. A robot having a drive train with at least one robot arm carrying, at its free end, an end-effector as claimed in any one of the preceding claims.

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