JPH0312057Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a magnetic levitation transfer device for vacuum equipment used, for example, in the transportation of semiconductor wafers in vacuum process equipment and in the manufacturing process of pharmaceuticals.

Conventional technology Conventionally, there has been a magnetic levitation system as a mechanism that allows parallel movement in the atmosphere without sliding or contacting.
Usually, a floating object is equipped with a position sensor, an electromagnet, a power source, etc. A linear pulse motor mechanism is used as a driving means in this type of mechanism.

By the way, no mechanism has been proposed in the past that can move long distances in parallel in a vacuum without sliding and without generating dust. This is desired from the viewpoint of preventing pollution and inline processes. In other words, due to the recent trend toward higher integration of semiconductor devices, contamination of the substrate by dust must be kept as low as possible not only during substrate processing but also during transfer from one processing step to the next processing step. Furthermore, releasing a vacuum when transferring a substrate from one processing step to the next is not only undesirable from the perspective of dust, but also from the perspective of time and energy consumption for the entire process, and these issues arise. As a means of solving this problem, there has been a strong demand for a mechanism that can move long distances in parallel in a vacuum without sliding and without generating dust.

In order to meet these requirements, if we try to apply the magnetic levitation system that has conventionally been used in the atmosphere to vacuum process equipment, although there will be no problem with dust due to contact or sliding, the electromagnets, power supply, etc. will be in the vacuum. This creates a serious problem of gas generation. Gas generated from such electromagnets, power supplies, etc. will have a negative effect on the object to be processed.

Therefore, in the application filed on the same date, permanent magnets are attached to both sides of a floating body member that levitates and supports a conveyance table guided along a conveyance path formed in a vacuum device, and in cooperation with each of these permanent magnets, the above-mentioned levitated A levitation electromagnet for guiding the body member in a non-contact and balanced state throughout the transport path of the transport platform is provided on the outside of the wall of the vacuum apparatus, and a plurality of equally spaced and parallel teeth are provided on one side. A movable element made of a magnetic material is provided on the floating body member, and a large number of windings, which are positioned opposite to the movable element and are sequentially excited to drive the movable element, are attached to the outside of the wall of the vacuum apparatus. We have proposed a magnetic levitation transfer device for a vacuum device in which a stator is provided on the wall of the vacuum device along the movement path of the floating body member.

This proposal solved the problem of gas generation as well as dust, and made it possible to use the device even in a vacuum.

Problems to be Solved by the Invention When parallel movement is performed using a linear motor mechanism having a mover and a stator, as in the above proposal, the mover and stator are always maintained in accurate mutual positions. It is necessary to make sure that it is not tilted. Therefore, in a normal linear motor mechanism, a guide device is provided on the movable element or the stator to prevent the movable element from shifting diagonally. However, such a feeding device cannot be realized.

Therefore, an object of the present invention is to provide a magnetic levitation transfer device for a vacuum device that can be accurately and stably driven along a desired trajectory without using the conventional guide device as described above. .

Means for Solving the Problems In order to achieve the above object, the magnetic levitation transfer device for a vacuum device according to the present invention levitates and supports a transfer platform that is guided along a transfer path formed within the vacuum device. A floating body member is provided in a vacuum device, and permanent magnets for maintaining levitation are attached to both sides of the floating body member, and a magnetic movable element for driving is attached to the bottom end of the floating body member. is an electromagnet that moves together with permanent magnets attached to both sides of the floating body member, and a magnetic movable element attached to the lower end of the floating body member, which is sequentially excited in order to drive the movable element. a stator made of a magnetic material and having a large number of windings arranged as shown in FIG. The movable member is characterized in that a portion thereof sealingly penetrates the wall of the vacuum device and directly opposes the tooth row of the movable element.

Function In the magnetic levitation transfer device for vacuum equipment according to the present invention configured as described above, the rows of teeth extending in the horizontal direction provided on the opposing surfaces of the movable element and the stator generate a driving force, while the rows of teeth extending in the vertical direction generate a driving force. The extending teeth are adapted to generate a control force that prevents the mover from deviating from its normal trajectory.

Further, since the stator is directly adjacent to and opposed to the movable element located within the vacuum device, sufficient driving force can be efficiently transmitted.

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

FIG. 1 shows a magnetic levitation transfer device for a vacuum device according to an embodiment of the present invention, in which reference numerals 1 and 2 are vacuum device walls, and these vacuum device walls 1 and 2 are made of non-magnetic material. A carrier 3 is shown within the vacuum apparatus defined by these vacuum apparatus walls 1, 2;
It is adapted to be guided along a conveying path formed within the vacuum device. A floating member 4 made of a non-magnetic material is attached to the lower side of the carrier 3. As shown, permanent magnets 5 and 6 are attached to both sides of the floating body member 4, and a mover 7 made of a magnetic material is attached to the lower end of the floating body member 4. These components are the vacuum device wall 1,
It is housed within a vacuum device defined by 2.

Permanent magnets 5 provided on each side of the floating body member 4,
Floating electromagnets 8, 9, 10, and 11 are attached to the outside of the vacuum device wall 2 above and below, sandwiching each of the levitation magnets 6, respectively. Each of these electromagnets 8, 9, 10, 11 extends over the entire length along the moving path of the floating body member 4, and is connected to a large number of yokes 8a, 9a, 10.
a, 11a and a large number of windings 8b, 9b, 10b, 1
1b.

Further, a fixing member 12 is attached to the vacuum device wall 2 opposite to the lower side of the movable element 7, and is provided with a large number of windings 12a on the outside of the vacuum device wall 2, which are arranged to be sequentially excited. A portion of each stator core around which each winding is wound protrudes through the vacuum device wall 2 to a position facing the lower side of the movable element 7. Each winding 12a of stator 12 is connected to a pulsed power supply, not shown, and can be energized in a controlled manner. Further, in FIG. 1, the reference numeral 13 represents a position sensor, and the position sensor 1
3 detects the position of the floating body member 4 in order to control the energization of the windings of the floating electromagnets 8, 9, 10, and 11. Therefore, a large number of position sensors 13 are provided along the movement path of the floating body member 4.

As shown in FIG. 2, the movable element 7 and the stator 12 are provided with a tooth row 14 extending in the lateral direction and generating a driving force.
16, and longitudinally extending tooth rows 15 and 17 that generate a control force that always maintains the movable element 7 and the stator 12 in a predetermined positional relationship.
It is desirable that the interval A between the tooth rows 14 and 16 extending in the horizontal direction be set smaller than the interval B between the tooth rows 15 and 17 extending in the vertical direction.

In the illustrated embodiment, the movable element may be fixed and the stator may be movable.

In the operation of the device of the present invention configured as described above, the floating body member 4 is connected to the floating electromagnets 8, 9, 1
By energizing the windings 0 and 11, the floating body member 4 is maintained in an equilibrium state of floating without sliding or contacting with the conveyance table 3 due to mutual attraction with the permanent magnets 5 and 6. . When the linear pulse motor mechanism consisting of the movable element 7 and the stator 12 is energized, the tooth rows 14 and 16 extending in the lateral direction provided on the opposing surfaces of the movable element 7 and the stator 12, respectively, generate a driving force. On the other hand, the longitudinally extending tooth rows 15 and 17 generate a control force that prevents the movable element 7 from deviating from its normal trajectory. Therefore, the floating body member 4 and the conveyance table 3 can be moved in a predetermined direction to a predetermined position along the movement path without deviating from the normal trajectory. In this case, each position sensor 13 sequentially detects a position signal as the floating body member 4 moves, and this causes the floating electromagnets 8, 9, 10,
The energization of the 11 windings can be controlled. Also stator 1
By appropriately controlling the manner in which the second winding 12a is energized, the object to be transported can be transported softly without any impact or damage to the object.

Effects of the Invention As explained above, in the magnetic levitation transfer device for a vacuum device according to the present invention, the driving means includes a magnetic movable element attached to the floating body member, and a position opposite to the movable element for the vacuum device. a stator provided on the outside of the wall of the vacuum apparatus with a large number of windings arranged on the wall and sequentially excited to drive the movable element; Each row of teeth extends in the horizontal and vertical directions, so the floating body members can always be stably driven along the regular trajectory without using a special trajectory guide device that can generate dust as in the past. In addition to being able to efficiently transmit driving force,
As a result, it can be used satisfactorily even in ultra-high vacuum. Therefore, the present invention can provide a completely contactless conveying device.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing a magnetic levitation transfer device for a vacuum device embodying the present invention, and FIG. 2 is a plan view showing the configuration of the main parts of the device according to the present invention. Teeth extending in the horizontal direction, 15, 17: Teeth extending in the vertical direction.

Claims (1)

[Scope of utility model registration request] A floating body member for floating and supporting a conveyance table guided along a conveyance path formed in the vacuum apparatus is provided in the vacuum apparatus, and the floating body member has permanent magnets for maintaining levitation on both sides thereof, and a lower end thereof. A magnetic movable element for driving is attached to each part, and an electromagnet that operates together with the permanent magnets attached to both sides of the floating body member is attached to the outside of the vacuum device wall, and an electromagnet is attached to the lower end of the floating body member. A stator made of a magnetic material and having a large number of windings that are sequentially excited to drive the movable member is provided to face the attached magnetic mover, and the mover and the stator are opposed to each other. The surfaces thereof are provided with rows of teeth extending in the horizontal and vertical directions, respectively, and the portion of the stator provided with the rows of teeth sealingly penetrates the wall of the vacuum apparatus and directly opposes the row of teeth of the movable element. Features: Magnetic levitation transfer device for vacuum equipment.