EP4315405A1

EP4315405A1 - Contactless conveying device

Info

Publication number: EP4315405A1
Application number: EP22713946.6A
Authority: EP
Inventors: Heike Raatz; Philipp Guth; Joachim Frangen
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2021-03-25
Filing date: 2022-03-14
Publication date: 2024-02-07
Also published as: DE102021202915A1; CN117083702A; JP2024511791A; US20240174459A1; WO2022200094A1

Abstract

The invention relates to a conveying device designed to convey one or more payloads, more particularly wafers, by means of transport bodies. The transport bodies can be floatingly moved and positioned over a transport surface of a stator. The moving and positioning are preferably carried out with respect to all six degrees of freedom. The transport body has a movable boom or a movable manipulator or a movable robotic arm. At the end effector thereof, the payload can be deposited or fastened. In developments, the payload can also be processed and/or checked. The processing and/or checking can also be carried out by an end effector of an additional transport body of the same conveying device.

Description

Non-contact conveyor

description

The invention relates to a non-contact transport device according to the preamble of claim 1. The transport device according to the invention is particularly suitable for industrial applications in assembly technology, biological, chemical, pharmaceutical and food industries as well as in solar cell/display production, medical technology, laboratory automation and logistics. The use of the transport device in the semiconductor industry is particularly preferred.

Within the scope of technical production, payloads such as materials, workpieces, tools or products often have to be transported or positioned. For this purpose, both contact and non-contact conveying devices are known, which are used, for example, in mechanical and plant engineering, for example for transporting payloads in packaging machines, for positioning machine elements or for the most precise possible alignment of tools on the workpiece, for example for laser processing, or in the Semiconductor industry for coating, exposure or structuring of substrates in wafer cluster or stepper systems. Systems for magnetic levitation can be used here.

A challenge in magnetic levitation is to create a structure that levitates stably in a magnetic field. Another challenge is to automatically position and/or move the levitating structure in all six degrees of freedom (three each in translation and rotation) according to a target, also known as full magnetic levitation.

According to DE 102016224951 A1, such a controlled transport and positioning of a transport body carrying a payload relative to a stator is made possible by one of the two elements being transported over a plurality of at least partially movably arranged actuating magnets, the respective position and/or orientation of which relative to this element can be specified in a controlled manner via actuating elements, and the other of the two elements has at least two stationary magnets immovably connected to this element, the stationary magnets being magnetically connected to the actuating magnets are coupled. The transport device is set up to transport the transport body relative to the stator by controlled positioning and/or orientation of actuating magnets. In this case, the transport body is also brought and held in a desired position and/or orientation relative to the stator.

DE 102016224951 A1 offers the advantage that a levitation and/or a forward movement of the transport body relative to the stator is made possible by appropriate positioning and/or orientation of the actuating magnets by means of the respective actuating elements. As a result, there is no need to provide a complex arrangement and control of magnetic coils. This not only reduces the complexity of the transport device and thus the production costs, but also allows the use of permanent magnets, which can often provide a much higher flux density than magnetic coils that can be used for such purposes. This in turn can allow for a greater lifting height or a larger gap between the stator and the transport body, which can result in a greater freedom of movement for movements in the Z direction and/or in the pitch and roll angle range. Furthermore, this offers the advantage that even an interruption in the supply of electrical energy does not necessarily have to lead to a malfunction or even cause damage. In particular, an interruption in the power supply does not lead to a loss of the magnetic field or the magnetic coupling between the stator and the transport body. For example, in the event of an interruption in the power supply, the coupling forces between the actuating magnets and the stationary magnets can increase as soon as the position and/or the orientation of the actuating magnets gives way to the attractive force of the stationary magnets, whereupon the transport body is pulled onto the stator and is thus secured against uncontrolled falling . The magnetic coupling between the stator and the transport body can cause both a levitation of the transport body, ie a lift above the stator, and a movement of the transport body relative to the stator, ie transport without the need for other touching or touchless systems.

Contactless transport is thus made possible, so that the disclosed transport device can also be used in environments with increased cleanliness requirements. For example, the transport body can be conveyed in the environment with the increased cleanliness requirement, while the stator is arranged outside in an environment with lower cleanliness requirements. Separating elements can run through a gap between the stator and the transport body in order to separate the different cleanliness areas. The disclosed conveying device is thus also suitable for use in biological, chemical and/or pharmaceutical processes, as well as, for example, in gas-tight, liquid-tight and/or encapsulated areas.

In a typical semiconductor production line, wafers are processed in production equipment (e.g. cluster tools). Wafers are usually transported under normal pressure in transport containers between the production plants, with the transport taking place as a lot with a typical lot size of 25 pieces. Within a manufacturing facility, the wafers are usually processed and transported under ultra-high vacuum (UHV). A production facility comprises at least one process station for processing the wafers, a generic transport device for transporting the wafers in a vacuum, and a storage area for storing unprocessed and processed wafers. The at least one process station, the transport device and the storage area are enclosed in vacuum-tight chambers and can be evacuated to UHV. The chambers are arranged laterally adjacent to one another and are connected to one another—possibly via vacuum-tight locks.

A so-called vacuum load lock is located on the production system for transferring the wafers between the transport container and the production system and for storing several wafers in the vacuum area. The transport container is inserted into the Vacuum Load Lock under normal pressure, and then the Vacuum Load Lock is evacuated. A vacuum lock then opens between the Vacuum Load Lock and the conveyor area of the fabrication facility and the wafers are removed from the transport container through the lock by the transport device or inserted into the transport container.

After all wafers have been removed from the transport container, processed and placed back in the transport container, the vacuum lock is closed and the vacuum load lock is aerated. The transport container is then removed from the Vacuum Load Lock under normal pressure and transported to the next production facility, for example.

The object of the present invention is to provide a transport device that enables complex and efficient movement sequences. The range of functions of the transport body should be expandable to include functions for handling, positioning, fixing, e.g. clamping, processing and/or testing payloads that are on the transport body or in the vicinity of the transport body. In technical production or in logistics, new functions and processes with a high degree of automation, high efficiency and high cost-effectiveness should be made possible.

This object is achieved by a transport device having the features of patent claim 1. Further advantageous refinements of the invention are described in the dependent patent claims.

The transport device according to the invention is designed for the contactless movement of at least one transport body (mover), which is equipped with a manipulator. The manipulator is connected to the transport body--more precisely, to its housing--either as a replaceable module or as a fixed part of the transport body, and is carried along by it. The transport body with the connected manipulator can be positioned in its six degrees of freedom of movement in relation to the stator by the magnetic field of a stator. In addition, the manipulator has at least one further degree of freedom of movement, which can be positioned in relation to the housing of the transport body when the transport body is in suspended operation. Complex and efficient movement sequences are possible through synchronous movement control of the degrees of freedom of the housing and the manipulator. The manipulator expands the range of functions of the transport body by functions for handling, positioning, fixing, eg clamping, processing and/or checking payloads that are on the transport body or in the vicinity of the transport body. The transport body with manipulator opens up numerous new fields of application for the transport device according to the invention. In technical production or in logistics, it enables new functions and processes with a high degree of automation, high efficiency and high cost-effectiveness.

The manipulator carried on the transport body according to the invention replaces stationary manipulators that would have to be provided at the loading and destination locations if the transport body did not have its own handling function. The higher the number of positions to be approached, the greater the savings in stationary components and thus the reduction in complexity and costs of the overall system.

In a typical application, the manipulator has an end effector with which a payload is loaded onto the transport body at the loading location and set down at the destination. The manipulator can also have a clamping function with which the payload is held securely on the transport body during transport. Furthermore, the manipulator can be provided for reorienting the payload during transport in order to hand over the payload in the correct orientation at the destination without any additional expenditure of time.

In another application, the manipulator is a kinematic system that guides the end effector, eg a process tool or a test device. The transport body equipped in this way can process carried payloads or payloads in its environment with the tool or check them with the test equipment. He has a high flexibility of movement. Another advantage in terms of time or economy results from the parallelization of processes with simultaneous execution of the transport and manipulation tasks. In addition, a manipulator may be equipped to perform multiple functions (e.g. handling and testing). Furthermore, several manipulators can be present on one transport body. Finally, there can be several transport bodies that perform a task together. For example, a workpiece is fixed and transported on a first transport body without a manipulator. A second transport body with a manipulator accompanies the first transport body and uses the manipulator to carry out handling, processing or testing tasks on the transported workpiece.

The already mentioned reorientation of the payload can also be made possible by means of several transport bodies of the transport device according to the invention.

Particular advantages result when the conveying device according to the invention is used in the semiconductor industry if the workpiece is a wafer, for example. The transport body is advantageously used to transport a semiconductor wafer in a vacuum transport space of a production plant. The stator is arranged under the vacuum transport space. A typical transport task in such a manufacturing plant (cluster tool) consists in removing the wafer from a process nest of a process station and conveying it into the process nest of another process station. Since the process stations in a production plant are arranged laterally next to the transport space and therefore cannot be reached directly by the transport bodies, the manipulator according to the invention bridges the transport route from the process nest into the transport space. The manipulator according to the invention makes it possible to pick up and set down the wafer spatially offset to the transport space or to the transport device, with the center of gravity of the wafer being able to be far away from the transport body.

The manipulator has at least one degree of freedom, which guides the end effector—possibly loaded with a payload (a wafer)—on a movement path (eg from the process nest) to the transport body. The kinematics contract and form a compact unit with the transport body and the payload (the wafer), which occupies about 2 - 4 times less transport area than a comparable transport body with a rigid end effector. For example, the manipulator is extended in front of a process nest for loading and unloading. During the transport he is in the contracted state so that the transport body is better manoeuvrable. The saved transport area can be used to increase the number of transport bodies via the stator (in the transport space) and thus to increase the throughput and the efficiency of the transport device (the production plant). The manipulator can be positioned variably. With the transport body in the same position on the transport surface, it can move the payload (the wafer) to any intermediate position between its end positions. In the case of the production plant for wafers, process nests can be loaded at different distances from the transport surface of the stator.

In addition to the contraction movement, the manipulator can have other degrees of freedom. For example, a manipulator with two degrees of freedom can be provided, with a first degree of freedom executing the contraction movement described in a plane parallel to the transport surface and a second degree of freedom executing a flow movement perpendicular to the transport surface. Although the lifting movement can already be positioned as the wheel of freedom of the transport body, the adjustment range is narrowly limited due to the levitation process. The manipulator can be designed for a larger lifting range. A transport body equipped with this manipulator is able to load process nests arranged at different heights with wafers. It is also possible to load a wafer cassette in a load lock, with one of several compartments of the wafer cassette arranged vertically one above the other being able to be loaded in a targeted manner.

Compared to a transport body without a manipulator, the following advantages are achieved or can be achieved with preferred configurations: a) Extended work area: The manipulator can have kinematics which, within the scope of their degrees of freedom, extend beyond the limits of the transport body and thus reach places that are outside the work area of a transport body without a manipulator. For example, locations to the side of the transport surface are reached or locations at different heights above the transport surface. b) Reduced complexity of the overall system: the manipulator can pick up payloads at different deployment locations, transport them to the transport body and set them down again at a destination without further stationary Handling devices are required. A mobile manipulator can, if necessary, replace several stationary manipulators. This reduces the complexity and costs of the overall system. c) Reduced transport area: In order to keep the external dimensions of the transport body with manipulator and payload small, the manipulator can transport the payload to the center of the transport body, in particular over its housing. The transport area occupied by the transport body is thus minimized during transport, for example by a factor of 2-4 compared to a transport body with a rigid end effector. This has several beneficial effects, which are described in d) - f). d) Higher throughput: With the procedure described in c), more transport bodies can be accommodated on a given transport surface, so that the throughput increases. e) Small plant size: With a given number of transport bodies, the transport area can be reduced with the procedure described in c), which leads to significant cost advantages in a vacuum transport room with high operating costs in semiconductor production, for example. f) Better manoeuvrability: with the procedure described in c), the transport body can assume small external dimensions, it is then easier to manoeuvre. Compensatory movements are eliminated, the movement paths are shorter, maneuvers are accelerated, turning maneuvers can be carried out on the spot without impeding other transport bodies, even in a transport space with small dimensions. g) Gain in time and efficiency: handling, processing or testing tasks on a payload can be performed while the payload is being transported. This parallelization of processes reduces the processing cycle time. h) Purely mechanical construction: The device consisting of transport body and manipulator can be constructed purely mechanically, without electrical or electronic components. The stator is responsible for precise positioning and provides the mechanical energy to move the transport body and drive the manipulator. The energy is transferred from the stator to the transport body or its manipulator by means of the magnetic fields. This makes the structure very space-saving, light and inexpensive. Since no energy store has to be carried along, no time or space has to be planned for electrically charging the energy store. Without electronics, there is no heat loss, the need for Cooling is not required. This is particularly advantageous in a vacuum, where there is little heat dissipation from the levitated device by radiation. A purely mechanical design can be designed for significantly higher operating temperatures, since the usual temperature limitation to protect the electronics and the energy storage device is no longer required. The purely mechanical device can be optimized for use under special conditions, in particular in a vacuum (when using vacuum-compatible materials), in potentially explosive areas (since there is no risk of electrical sparking), in a gas atmosphere or in liquids, even under the highest ambient pressure. i) Flexibility through modularity: The mechanical interface between the transport body and the manipulator can have quick-action clamping devices and couplings, so that different types of manipulators can be used alternately on different types of transport bodies. The manipulator can be exchanged quickly and easily, manually or automatically, in order to prepare the transport body for a new application.

The transport bodies and the associated payloads are preferably accommodated in a sealed transport space. The stator is arranged below the sealed transport space. The respective housings of the transport bodies are preferably also sealed. This creates a transport device for payloads, in particular wafers, which can be processed in different process stations under special surroundings, that is to say not under normal conditions. The transport of the payloads by means of the transport bodies of the transport device according to the invention also takes place in a special environment, ie not under normal conditions.

A gas (e.g. protective gas,

nitrogen or inert gas) or a gas mixture (e.g. purified air) or a vacuum or an ultra-high vacuum (e.g. up to 10 ⁷ or up to 10 ⁸ bar) or an aseptic area or an NBC-protected area or a liquid (e.g. up to 2 bar). .

Various exemplary embodiments of the transport device according to the invention with various exemplary embodiments of transport bodies are shown in the figures. Show it

1 shows three different exemplary embodiments of the conveying device according to the invention,

FIG. 2 three different exemplary embodiments of magnet arrays of the transport body from FIG. 1,

figs 3a, 3b and 3d three exemplary embodiments of arrangements of magnet arrays in a housing of the transport body from FIG. 1a or 1b,

figs 3c and 3e two exemplary embodiments of arrangements of magnet arrays in a housing of the transport body from FIG. 1c,

4 shows the housing with the magnet arrays from FIG. 3a,

Fig. 5 shows a transport body with a housing that that of Figs. 3a and 4, with a telescopic manipulator,

Fig. 6 shows a transport body with a housing that that of Figs. 3a and 4, with a bendable manipulator,

7 shows a transport device with the transport body with the telescopic manipulator according to FIG. 5,

8 shows a method for controlling the movement path of a transport body with a manipulator,

9 shows a production plant for the semiconductor industry with a conveying device according to the invention,

10 shows a method for quickly changing a wafer in a process station using the conveying device according to the invention,

11 shows a method for transferring a wafer from one transport body to another transport body of the conveying device according to the invention without intermediate storage, and

12 shows a method for transferring the wafer, in which the angular position of the wafer can be changed in the full range of 360°, using the conveying device according to the invention.

Three variants of conveying devices according to the invention are shown schematically in Figs. 1a to c shown. They each comprise a stator 3 and at least one transport body 2, which is transported in a controlled manner relative to the stator 3 without contact. For this purpose, the stator 3 has movably arranged actuating magnets 31 (cf. FIG. 7) in a planar arrangement, the orientation of which is controlled by actuators is changeable. The superimposition of the magnetic fields of all the adjusting magnets 31 results in a magnetic field, which is referred to here as a levitation field. It passes through a top plate of the stator 3 upwards. At the same time, the cover plate forms the transport surface 33, over which transport bodies 2 equipped with magnet arrays are transported without contact.

A sensor system cyclically detects the position of each transport body 2, more precisely its housing 21, in its six degrees of freedom of movement over the transport surface 33 with high frequency and accuracy. As with any rigid body, these are three degrees of freedom in translation X, Y, Z and three in rotation rX, rY, rZ of the housing 21. From this, a controller calculates the deviation in position from a specified desired position or a desired trajectory and controls the magnetic angle in such a way that the deviation is minimal. In this way, the housing 21 of the transport body 2 is guided on the desired trajectory in a stable and robust manner against external forces.

In the exemplary embodiments according to Figs. 1a and 1b, the transport body 2 has a drive unit 23 for the housing 21, which comprises at least one magnet array 231 fixed to the housing (cf. FIG. 2). During operation, the magnet array 231 experiences forces and moments in the levitation field, which are transmitted to the rigidly coupled housing 21 and drive it to move. In this way, the magnet array 231 acts as a drive unit 23 for the housing 21.

So that the drive can be regulated, the drive unit 23 includes a means for detecting the position of the housing 21. The position is detected in relation to the stator 3 by attaching a position sensor to one of the two components and attaching a code arrangement 233 to the other, which is generated by the Position sensor is detected. A camera-based method for position detection can be used, for example, in that a camera module 32 attached to the housing 21 detects a code arrangement 233 on the stator 3 . According to Figs. 1a and 1b, a camera module 32 integrated in the stator 3 (cf. Fig. 7) detects a code arrangement 233 on the housing 21. According to the invention, the transport body 2 carries with it a movable and controllable manipulator 22 for a payload (not shown in FIG. 1), the manipulator 22 being fastened to the housing 21 . The manipulator 22 includes a kinematic system 221 with an end effector 222 which, depending on the task, is designed as a tray, gripper, clamping device, tool or test equipment.

The end effector 222 is preferably fastened to the kinematics 221 as a quickly exchangeable component and/or the kinematics 221 as a quickly exchangeable component to the housing 21, so that the transport body 2 can be quickly set up for a new task by manually or automatically changing the manipulator 22 or the end effector 222 can be prepared. It includes structural components and joints that give the end effector 222 at least one degree of freedom of movement in relation to the housing 21 . A joint is, for example, a rotary bearing, a linear guide, a guide with solid-state joints or a combination of these.

For the controlled or regulated movement of the kinematics 221 in its at least one degree of freedom, the manipulator 22 is connected to a drive unit 24 via a coupling 26, which transmits kinetic energy to the kinematics 221 and enables controlled positioning. In order to control kinematics 221 with multiple degrees of freedom, a drive unit 24 with multiple degrees of freedom can be present, or multiple drive units that serve all the degrees of freedom of kinematics 221 overall.

1 b shows a transport body 2 of purely mechanical design with a mechanical drive unit 24 for the manipulator 22 . It comprises a magnet array 241 which is connected to the housing 21 of the transport body 2 via a bearing 244 . The bearing 244 allows the magnet array 241 to move in at least one degree of freedom in relation to the housing 21. The magnet arrays 231 and 241 are arranged at a lateral distance on the underside of the transport body 2, so that both are in the effective range of the levitation field and those acting between them Forces and moments are small in relation to the forces and moments they experience in the levitation field. The levitation field of the stator 3 exerts a vector force and a vector moment on the movable magnet array 241 . The force vector and the moment vector are split along the guiding direction of the bearing 244 into two vectorial components, one of which acts in the guiding direction of the bearing 244 and the other orthogonally to the guiding direction. The portion in the guiding direction is transmitted from the movable magnet array 241 via an output 245, for example a shaft or a connecting rod, and a clutch 26 to the kinematics 221 and can set them in motion. A gear can also be provided in order to adapt the number of revolutions of the output to the number of revolutions of the kinematics 221 . The proportion transverse to the guiding direction is transmitted from the magnet array 241 via the bearing 244 to the housing 21 and influences its movement, together with other magnet arrays.

A code arrangement 243 on the movable magnet array 241 enables its position in relation to the housing 21 to be detected. In this way, the position of the magnet array 241 can be controlled. With a mathematical model of the manipulator 22, the position of the magnet array 241 can be transformed into the position of the end effector 222 and vice versa if the magnet array 241 is rigidly coupled to the end effector 222 via the coupling 26 and the kinematics 221. By using the transformation, the position of the end effector 222 can also be specified as a target variable for the regulation.

For use under special environmental conditions as in

• Cleaning of transport body 2 (separation wet on the outside / dry on the inside),

• Use under vacuum (separation of vacuum on the outside / gas filling on the inside),

• Food or pharmaceutical area (separation aseptic on the outside / non-aseptic on the inside),

• A sealed housing 21 for the transport body 2 is useful in explosion-proof areas. Then the coupling 26 between the output of the transport body 2 and the manipulator 22 can also be designed as a magnetic coupling with non-contact torque transmission. For example, the housing 21 of the transport body 2 is tightly closed in an application under vacuum in order to separate the atmosphere in the transport body 2 from the surrounding vacuum. Since a mechanical rotary union in the Housing wall would destroy the tightness, a magnetic coupling can be used advantageously.

In another development, the drive unit 24 can form an assembly with the manipulator 22 . For example, the magnet array 241 and the code arrangement 243 can be integrated into a joint of the kinematics 221, with the bearing 244 and the coupling 26 being omitted. If the magnet array 241 is in the effective range of the levitation field, it can be subjected to forces and moments via the stator 3, which are then transmitted directly to the kinematics 221. If the manipulator 22 is exchanged, the drive unit 24 is necessarily exchanged as well.

The manipulator 22 in FIG. 1 a can be driven either electrically with an electric motor or mechanically with the drive unit 24 . In the first case (electric drive), the electric motor is supplied with electrical energy and data for the target position via an electronic unit 25 . In the latter case (mechanical drive), an electronics unit 25 can also be provided in the housing 21 in order, for example, to supply current to position sensors accommodated in the housing 21 .

The electronics unit 25 includes the following electrical or electronic components, which are optionally present in the transport body 2: an energy store 251, for example an accumulator or a capacitor, for providing the electrical energy, and consumers, for example

• a wireless communication interface 252 for communication with a base unit in the stator 3,

• a sensor system for detecting the degrees of freedom of the transport body 2 and the manipulator 22,

• an electric drive unit 24 for the manipulator 22,

• a user interface 253 which provides the user with energy and data supply for additional application-specific units on the transport body 2 . In a preferred variant according to FIG. 1b, the transport body 2 with the manipulator 22 is constructed purely mechanically or passively. The electronics unit 25 is omitted. This has the following advantages:

• reduction in size, weight and complexity of the transport body 2,

• Saving the time and space required to charge an energy storage device 251,

• Enabling or simplifying use under extreme environmental conditions (e.g. high temperature, vacuum, high pressure, humidity).

1c shows a variant of a purely mechanical construction of a transport body 2, in which a combined drive unit 24 for the housing 21 and the manipulator 22 is used. In contrast to the exemplary embodiments of Figs. 1a and 1b, none of the magnet arrays 241 is permanently connected to the housing 21; each has its own bearing 244 and its own degrees of freedom of movement.

The bearings 244 are designed and arranged in relation to the housing 21 in such a way that a controlled movement of the housing 21 in all six degrees of freedom is possible at all times. If a magnet array 241 cannot control a degree of freedom of the housing 21, there is at least one further magnet array 241 which serves this degree of freedom. Appropriate design of housing 21 and bearings 244 eliminates singular positions of magnet arrays 241 where housing 21 is only controllable in five or fewer degrees of freedom.

2 shows exemplary ring-shaped magnet arrays with permanent magnets, which can be used as magnet arrays 231 fixed to the housing and as magnet arrays 241 movable relative to the housing 21 .

3 shows five different arrangements of magnet arrays 231 ,

241 with and without bearing 244 in a housing 21 of a transport body 2.

Fig. 3a: The housing 21 carries a rigidly coupled magnet array 231 and a rotatably mounted magnet array 241 in rZ. The degree of freedom rZ can act as a drive for a Manipulator 22 can be used, while the remaining five degrees of freedom X, Y, Z, rX, rY of the magnet array 241 are rigidly coupled to the magnet array 231 via the bearing and the housing 21 . They are therefore available in addition to driving the housing 21 and expand the working range of the forces and moments that can be exerted on the housing 21.

Fig. 3b: As Fig. 3a, but with a concentric arrangement of the two magnet arrays 231 and 241. In order to minimize the magnetic coupling between the magnet arrays 231, 241, their distance is maximized by making the inner diameter of the magnet array 231 significantly larger than the Outer diameter of the magnet array 2.4.1.

3c: A housing 21 with two magnet arrays 241a and b each rotatably mounted in rZ. Two degrees of freedom are thus available on the housing 21 for driving a manipulator 22 . According to FIG. 1c, none of the magnet arrays 241 is rigidly connected to the housing 12. FIG. Nevertheless, the housing 21 can be controlled in all six degrees of freedom. In particular, it can be moved in rZ by a rotational movement of the two magnet arrays 241 about a common center of rotation.

FIG. 3d: As in FIG. 3c, this arrangement has two magnet arrays 241a and b mounted rotatably in rZ, but in a concentric arrangement. In addition, a fixed magnet array 231 is present. Without the fixed magnet array 231, the housing 21 would not be steerable in rZ: since the axes of rotation of 241a and b coincide, no torque Mz can be applied to the housing 21. For example, two concentrically mounted hollow shafts can be used as output for the concentrically arranged magnet arrays 241a and b.

Fig. 3e: Housing 21 for driving a manipulator 22 with three degrees of freedom. Structure analogous to FIG. 3c, but with three magnet arrays 241.a, b and c rotatably mounted in rZ.

FIG. 4 details the construction of the housing 21 from FIG. 3a through a side view. It shows a rotary bearing 244 which guides an output 245 formed as a shaft. This is connected to a magnet carrier in the housing 21, which Magnet array 241 carries. The rotation of the magnet array 241 about the Z-axis is provided via the output 245 on the housing 21 or transmitted to the top of the housing 21 .

The shaft can be connected to the manipulator 22 via the coupling 26 . Next to it is the magnet array 231 , which is firmly connected to the housing 21 via the magnet carrier 232 . A code arrangement 233, 243 is attached to the underside of both magnet arrays 231, 241 in each case. The code arrangements 233, 243 can be read by the camera modules 32 in the stator 3 through a transparent housing base 212 (cf. FIG. 7).

FIG. 5 shows the housing 2 of FIG. 4 in connection with a two-stage linear manipulator 22 with one degree of freedom. More specifically, Fig. 5a is a top view showing the contracted state of the linear manipulator 22 and Fig. 5b is a top view showing the extracted state of the linear manipulator 22 and Fig. 5c is a side view showing the contracted state of the linear manipulator 22 and Fig 5d in a side view the extracted state of the linear manipulator 22.

The linear manipulator 22 from FIG. 5 has a linear guide as the first stage 2211 and a linear guide mounted thereon as the second stage 2212. An end effector 222 for receiving a payload 4 is attached to the second stage 2212, here a wafer for the semiconductor industry is shown. A belt pulley 261 is mounted on the output 245 of the magnet array 241 , which is formed as a shaft, and drives the two-stage linear manipulator 22 via a transmission belt 262 . In the contracted state, the transport body 2 with the payload 4 has very compact external dimensions, while in the expanded state the manipulator 22 can reach a process nest in a process station PM (see FIG 4 to load or to remove a wafer 4.

Since the manipulator 22 can be freely positioned in terms of its degree of freedom, the end effector 222 can also reach process nests at intermediate positions between the two end positions of the end effector 222 . For applications with the highest Cleanliness requirements, such as the handling of wafers 4 in a vacuum, are preferably used linear guides or roller bearings, which are at least partially made of ceramic, or flexure joints.

FIG. 6 shows the transport body 2 from FIG. 4 in connection with an articulated arm manipulator 22 with one degree of freedom. More specifically, FIG. 6a is a top view showing the contracted state of the articulated manipulator 22, and FIG. 6b is a top view showing the extracted state of the articulated manipulator 22, and FIG. 6c is a side view showing the contracted state of the articulated manipulator 22 and Fig. 6d in a side view the extracted state of the articulated arm manipulator 22.

Like the manipulator 22 in FIG. 5, the articulated arm manipulator 22 from FIG. 6 guides the payload 4 on a linear path and assumes compact external dimensions in the contracted state. This manipulator 22 can also be freely positioned and can reach process nests at different distances from the transport body 2 .

Ceramic bearings or flexure joints are also preferred here if the highest cleanliness requirements have to be met. The kinematics 221 is connected to the housing 21 via a mounting flange 223 .

FIG. 7 shows an exemplary embodiment of the transport device according to the invention with the transport body 2 from FIG. 5 on the stator 3 . The stator 3 is formed here from three identical stator modules. The sectional view shows the regular arrangement of the actuating magnets 31 and actuators in the stator 3, as well as the regular arrangement of the camera modules 32, which read the code arrangements 233, 243 attached to the magnet arrays 231, 241. The code arrangements 233, 243 not only contain the position information, but also an identification code, via which they can be unambiguously assigned to a magnet array 231, 241 in a specific transport body 2. Depending on the constellation, a code arrangement 233, 243 is recorded simultaneously by a number of camera modules 32, so that each magnet array 231, 241 is localized several times.

This redundancy can be used to increase the accuracy of the position detection of the code arrangement 233, 243 by averaging. The camera modules 32 supply the position and identification data of the detected code arrangements 233, 243 to the Plant control, which determines the actual position of the transport body 2 and the manipulator 22.

The movement control of the transport body 2 according to the invention with manipulator 22 places increased demands on the control of the actuating magnets 31 in the stator 3 in terms of the number of degrees of freedom. While a transport body 2 known from the prior art usually has six degrees of freedom of movement, the proposed mechanical transport body 2 with manipulator has 22 more than six degrees of freedom. The number results from the sum of the degrees of freedom of the housing 21 and the manipulator 22. If, for example, the manipulator 22 has one degree of freedom, the transport body 2 has a total of 7 (=6+1) degrees of freedom.

FIG. 8 shows a method for controlling the movement path of a transport body 2 with a manipulator 22. The method is implemented as an algorithm in the system control. The following steps a) - e) are carried out cyclically in a program loop with a fixed frequency in the range of about 100Hz - 10,000Hz: a) The position of the transport body 2 is determined in all degrees of freedom by means of distributed position sensors, in particular with camera modules 32, im Stator 3 or in the transport body 2 detected. These observe code arrangements 233, 243 on a magnet array 231, 241 or on other moving parts and derive the relative position between the position sensor and the code arrangement 233, 243 from this. All position information is transmitted to the system control. b) A kinematic model of the transport device is stored in the system control, in which the geometry of the components and the locations of the joints, bearings, position sensors and the code arrangements 233, 243 are described. The actual position of all magnet arrays 231, 241 in the stator coordinate system is calculated from the model and the data from the position sensors by means of a geometric transformation. c) The positional deviation of the magnet arrays 231, 241 is calculated as the difference between the actual position of the magnet arrays 231, 241 and a predetermined desired position in all degrees of freedom. To the transport body 2 with manipulator 22 dynamic on a target trajectory, the target position is changed incrementally in each loop run according to the target trajectory. d) A position controller converts the position deviations into a vectorial target force and a vectorial target moment for each magnet array 231, 241. This is achieved, for example, with a PID algorithm that is applied for each of the degrees of freedom involved. e) The force/torque control determines the target position of the actuating magnets 31 in the stator 3 from the vectorial target force and the target torque of all magnet arrays 231, 241 and the actual position of all magnet arrays 231, 241 and the actual position of all Adjusting magnets 31 in the stator 3 and a geometric model of all magnet arrays 231, 241 and a physical model of the magnetic interaction. The target position is optimized in such a way that when the target position of all adjusting magnets 31 in the model is set, the predicted vectorial forces and moments that act on all magnet arrays 231, 241 match the target forces and target moments as best as possible. For this purpose, a measure is calculated with the help of an error function, which expresses the deviation of the modeled forces and moments from the target forces and moments as a numerical value. This error function extends to all magnet arrays 231, 241 involved and all their degrees of freedom. For example, an optimization algorithm or a neural network is used to minimize the error function. f) Output of the target angle to the actuators of the positioning magnets 31.

9 schematically shows a production plant for the semiconductor industry. A vacuum transport space VK is equipped with a glass floor, with the modules of the stator 3 being mounted outside the vacuum area under the transport space VK, so that the levitation field penetrates the transport space VK through the glass floor. Three transport bodies 2a, 2b and 2c float in the levitation field in the transport space VK: the transport bodies 2a and 2b are in the contracted state, while the transport body 2c is in the expanded state for loading an arc-shaped process nest of a process station PM. A high wafer throughput is achieved by the simultaneous operation of a plurality of transport bodies 2 at different process stations PM. In addition, wafers 4 can be conveyed through the process stations PM in an individual order, so that in a multi-variant production, different process sequences can be realized in one production plant.

10 shows, in four temporal steps 1 to 4, a method for quickly changing a wafer 4 in a process nest of a process station PM shown in the form of a circular arc, so that the process pause between two consecutive process sequences in the process station PM is minimal. For this purpose, two transport bodies 2a and 2b are located side by side in front of the process station PM. Between step 2 and step 3, transport body 2a removes the processed wafer 4a from the process station PM and transports it via its housing 21 by contracting its manipulator 22. During the contraction movement of transport body 2a, transport body 2b performs an expansion movement in order to move the next wafer to be processed 4b to be introduced into the process station PM.

The contours of the wafers 4 can temporarily overlap in the X/Y plane. To avoid collisions, the end effectors 222 of the two transport bodies 2a, 2b are guided on different surfaces or at different inclinations.

FIG. 11a shows a method for transferring a wafer 4 from one transport body 2a to another transport body 2b without intermediate storage.

In the illustration from FIG. 11b, according to a first variant of the method from FIG. 11a, the wafer 4 is transported with a symmetrically constructed end effector 222a, the wafer center lying laterally next to the line of symmetry of the end effector 222a. A second end effector 222b of the same type is rotated by 180°, approaches from the opposite side and is guided under the wafer 4. The pairs of fingers of the two end effectors 222a, 222b are laterally offset so that they do not collide. The center of the wafer is offset laterally with respect to the line of symmetry of the end effector 222b. The handover occurs by an upward movement of end effector 222b and a downward movement of end effector 222a.

In the representation from FIG. 11c, according to a second variant of the method from FIG. 11a, the respective fingers on the end effectors 222a, 222b are light attached asymmetrically, so that two end effectors 222a, 222b offset from one another by 180° can move towards one another along an imaginary center line without colliding.

12 shows a method for transferring the wafer 4, the angular position of which can be changed in the full range of 360°. For this purpose, a transfer takes place from a first transport body 2a with a manipulator 22 to a second transport body 2b, which is designed as a circular disk or whose housing has a circular surface on its upper side. The second transport body 2b picks up the wafer 4 centrally (step 2). The second transport body 2b serves as an intermediate deposit for the wafer 4. The wafer 4 is rotated by a predetermined angle about the Z axis (step 3). Then a third transport body 2c with a manipulator 22 takes over the wafer 4 in a new orientation (step 4).

A further variant for aligning the rotational position of a wafer 4 with only one transport body 2 is described below. Two manipulators 22 are installed on a transport body 2 . A first manipulator 22 has two degrees of freedom, one to contract/expand the end effector 222 in the radial direction (as previously described) and another to flow the end effector 222 in the Z direction. A second manipulator 22 assumes the alignment of the rotational position of the wafer 4. It has one degree of freedom, the rotation about the Z axis perpendicular to the transport plane, and an end effector 222 for the central reception of the wafer 4. A wafer 4 lying on the end effector 222 can be rotated around its center. This arrangement makes it possible to remove a wafer 4 from a process nest with just one transport body 2, to transport it, to align the rotational position during transport and to deposit the wafer 4 at the destination in the intended rotational position. The following sequence of movements is provided for this purpose: a) Removal of the wafer 4 from the process nest: At the preparation location, the first manipulator 22 moves its end effector 222 under the wafer 4 lying in the process nest. After a lifting movement, the wafer 4 lies on the end effector 222. b) Contraction movement of the first manipulator 22. The wafer 4 is then located above the transport body 2, and the second manipulator 22 is now located centrally under the wafer 4. c) Transfer of the wafer 4 from the first manipulator 22 to the second manipulator 22 by a downward movement of the first manipulator 22. d) Alignment of the rotational position of the wafer 4 by rotation of the second manipulator 22. For alignment in relation to a notch in the edge of the wafer 4 (Notch), a sensor can be provided which monitors the position of the notch during the rotary movement. e) Transfer of the wafer 4 from the second manipulator 22 to the first manipulator 22 by a lifting movement of the first manipulator 22. The wafer 4 is now in the intended rotational position on the first manipulator 22. f) Depositing the wafer 4 at the destination with the first Manipulator 22.

A transport device is disclosed which is designed to transport one or more payloads 4 , in particular wafers, by means of transport body 2 .

The transport bodies 2 can be moved and positioned in a floating manner over a transport surface 33 of a stator 3 . The movement and the positioning preferably take place with respect to all six degrees of freedom. The transport body 2 has a movable boom or a movable manipulator 22 or a movable robot arm. The payload 4 can be placed or fixed on its end effector 222 . In further developments, the payload 4 can also be processed and/or checked. The processing and/or checking can also be carried out by an end effector 222 of a further transport body 2 of the same transport device.

Reference list:

2 transport bodies

21 housing

212 case back

22 manipulator

221 kinematics

2211 first stage

2212 second stage

222 end effector

223 mounting flange

23 drive unit (for housing)

231 body fixed magnet array

232 magnet carrier

233 code arrangement (for housing)

24 Drive unit (for manipulator) 241 Magnet array (movable relative to housing)

243 code arrangement (for manipulator)

244 bearing (for magnet array opposite housing)

245 downforce

25 electronics unit

251 energy storage

252 communication interface

253 user interface

26 clutch 261 pulley 262 transmission belt

3 stator

31 Solenoid

32 camera module

33 transport surface

4 payload/wafer LL LoadLock

PM process station

VK transport space

Claims

patent claims

1. Transport device for transporting at least one payload (4), each payload (4) being assigned at least one transport body (2, 2a, 2c) which can be moved and positioned in a floating manner over a transport surface (33) of a stator (3), wherein a boom or manipulator (22) or robot arm extends between an end effector (222) and a housing (21) of the transport body (2), wherein the end effector (222) can be brought into operative connection with the payload (4), characterized in that the cantilever or manipulator (22) or robot arm enables and controls at least a first degree of freedom of movement of the end effector (222) relative to the housing (21).

2. Conveyance device according to claim 1, wherein the first degree of freedom of movement is a variable distance of the end effector (222) to the housing (21) along or parallel to the transport surface (33).

3. Conveyance device according to one of the preceding claims, wherein the operative connection is carrying and/or handling and/or positioning and/or fixing and/or processing and/or testing carried out by the end effector (222) on the payload (4) is executable.

4. Conveyance device according to one of the preceding claims, wherein the boom or manipulator (22) or robot arm has a kinematic system (221) with at least two stages (2211, 2212) or sections.

5. Conveying device according to claim 4, wherein the steps (2211, 2212) or sections are linearly displaceable or pivotable relative to one another.

6. Conveyance device according to one of the preceding claims, wherein a plurality of process stations (PM) for processing the payload (4) are arranged laterally adjacent to the transport surface (33).

7. Conveying device according to claims 2 and 6, wherein process nests are arranged in the process stations (PM) which have a lateral distance to the transport surface (33), the distance being able to be bridged with the boom or manipulator (22) or robot arm in its extracted state is.

8. Conveyor device according to one of the preceding claims, wherein in a contracted state of the boom or manipulator (22) or robot arm a center point of the payload (4) or the payload (4) in sections or the payload (4) completely above the housing (21) of the transport body (2) is arranged.

9. Conveying device according to one of the preceding claims, wherein in the housing (21) of the transport body (2) at least one magnet array (231) is received and fixed, which can be brought into magnetic interaction with the stator (3) and moved by it.

10. Conveyance device according to one of the preceding claims, wherein at least one magnet array (241) is movably accommodated in the housing (21) of the transport body (2), which is mechanically coupled to the boom or manipulator (22) or robot arm, and which interacts magnetically can be brought with and moved by the stator (3).

11. Conveyance device according to claim 10, wherein the magnet array (241) is rotatably mounted in a bearing (244), and wherein a pulley (261) is rotatably fixed or coupled to the magnet array (241) via a transmission belt (262) mechanically is coupled to the boom or manipulator (22) or robotic arm.

12. Conveying device according to one of the preceding claims, with two transport bodies (2) whose - preferably symmetrical - end effectors (222a, 222b) are movable towards one another with a lateral offset.

13. Conveyance device according to one of claims 1 to 11, with two transport bodies (2) whose end effectors (222a, 222b) have two asymmetrical fingers.

14. Conveying device according to one of the preceding claims, with an additional transport body (2b) whose housing (21) is or has a rotatable disk.

15. Conveying device according to one of the preceding claims, wherein a transport space (VK) is formed above the transport surface (33), in which a gas or a gas mixture or a liquid, or a vacuum or an ultra-high vacuum or an aseptic area or an ABC protected area is provided, and wherein the at least one transport body (2) is accommodated in the transport space (VK).