JP3147494B2 - Magnetic levitation transfer device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer method and an apparatus for transferring electronic device members such as semiconductor wafers in a dust-free room. The present invention relates to a magnetic levitation transfer method that improves productivity and a magnetic levitation transfer device using the same.

For example, in a wafer process in a manufacturing process of a semiconductor device, all of the steps are usually performed in a dust-free room because the adhesion of fine dust has a great effect on the characteristics of a product as it is.

[0003] In this case, a transfer device for wafers and the like installed in the dust-free room is a method capable of transferring the wafer in a non-contact manner in order to suppress generation of abrasion powder and foreign matter, for example, a wafer carrier is moved while being floated by a linear motor. And other methods are frequently used.

[0004]

2. Description of the Related Art FIG. 3 is a view for explaining a conventional transfer method together with its apparatus configuration, and FIG. 4 is a view showing a circuit configuration of a conventional transfer apparatus.

In FIG. 3 and FIG. 4, a magnetic rail 1 having a flat cross section and fixed in a state of being suspended from a ceiling or the like is provided with iron (Fe) on both side convex portions 1a located on the lower surface side.
And a plurality of linear motors 1d _-1 , 1d _-2 ... Connected to the linear motor control unit 1c are provided on a concave portion located on the center line of the magnetic material 1b. It is arranged and arranged at every interval.

[0006] Also, under the magnetic rail 1, the rail 1
The bogie 2 that can move in a non-contact manner has its main body formed of a material which is not affected by a magnetic field such as aluminum (Al), and has a surface on the magnetic rail 1 side, that is, four corners of the upper surface 2a. At the position facing the magnetic material 1b, the magnetic material
A levitation electromagnet 3 having a function of holding the trolley 2 at a fixed separation distance (hereinafter referred to as a gap) from 1b (hereinafter referred to as levitation) and an instantaneous position or gap with respect to the trolley 2 are detected. And a state detector 4 having a function of transmitting a deviation from a reference gap, a gap direction moving speed when correcting to the reference gap, and the like as a signal, and two state detectors in a direction along the magnetic material 1b. The levitation electromagnets 3 are arranged between the levitation electromagnets 3 so that the information transmitted by the state detector 4 is corrected to a reference value.
The levitation control unit 5 having a function of passing a required current to the head is fixed.

Further, on the center line of the upper surface 2a of the carriage 2, the carriage 2 floating with respect to the magnetic rail 1 is moved in parallel with the rail 1 by a magnetic field from the linear motors 1d- ₁ , 1d- _2. The secondary conductor 6 for moving in the direction of movement is mounted.

Each of the above electronic devices is connected to a battery (not shown) mounted on the upper surface 2a. On the other hand, on the lower surface 2b of the carriage 2, a carrier 8 for accommodating a plurality of semiconductor wafers 7 in a stacked manner so as not to contact each other is suspended by, for example, a hook 2c.

[0009] Therefore, after floating in a predetermined position該台vehicle 2 in which a carrier 8 in which a plurality of semiconductor wafers 7 are accommodated is hung into the truck 2 by levitation electromagnets 3, a plurality of linear motors 1d _- By sequentially operating ₁ , 1d _-2 ..., The carriage 2 can be moved in a direction along the magnetic rail 1 in a non-contact manner.

In this case, for example, the first linear motor 1d _-1
Is moved by a magnetic field from the second linear motor 1d- ₂ and moved in the direction of arrow A.
The state detector 4 fixed above sends the position signal X ₁ , the deviation signal X ₂ , and the speed signal X ₃ in the gap direction to the levitation control unit 5 _every moment.

Therefore, the levitation control unit 5 applies a gain according to a normal control theory to each signal sent from the state detector 4.
Since K ₁ , K ₂ , and K ₃ are added and the calculated signal is sent to the electromagnet for levitation 3 as the manipulated variable U, the magnetic rail 1
The cart 2 can be moved in a state where the position with respect to is corrected at any time.

[0012]

In the conventional transfer apparatus having such a configuration, since the semiconductor wafer is transferred in a non-contact state, dust generation during transfer can be suppressed.

However, since the levitation control of the bogie is performed by simple feedback control with a constant gain, a large magnetic field, that is, a driving force (starting force) is generated by the linear motor.
When a braking force (stopping force) is applied, the levitation in a stable state cannot be maintained. You can't do that.

Therefore, since the driving force or braking force by the linear motor, in other words, the ability to generate a magnetic field can be used only within a limited range, sudden start and stop cannot be expected, and as a result, high speed can be achieved in a short time. There has been a problem that a transfer device with good working efficiency cannot be constructed and improvement in productivity cannot be expected.

[0015]

SUMMARY OF THE INVENTION An object of the present invention is to provide a linear motor which can move along a magnetic rail on which the linear motor is provided while maintaining a predetermined gap amount.
At least a levitation control unit for controlling the levitation electromagnet and a levitation control unit that controls the levitation electromagnet and a bogie including a secondary conductor that generates an attractive force or a repulsion force against the linear motor with a magnetic field generated from the linear motor are arranged. A magnetic levitation transport method for generating a required magnetic field and transporting the trolley along a magnetic rail with a predetermined gain, wherein a magnetic levitation for transmitting a gain change command to the levitation electromagnet (3) when the trolley is accelerated or decelerated. It is solved by the transport method.

A magnetic rail on which a linear motor is provided, and at least a levitation electromagnet and the levitation magnet so that the linear motor can move along the magnetic rail while maintaining a predetermined gap with respect to the magnetic rail. A magnetic levitation transport device comprising: a levitation control unit that controls an electromagnet with a predetermined gain; and a bogie having a secondary conductor that generates an attractive force or a repulsive force on the linear motor by a magnetic field generated by the linear motor. Thus, the problem is solved by a magnetic levitation transfer device having a CPU for gain adjustment capable of transmitting a gain change command to the electromagnet for levitation during acceleration and deceleration of the carriage.

[0017]

The feedback gain in the levitation control unit is automatically set so that the gain calculated by the levitation control unit is switched when the bogie is accelerated or decelerated, that is, when the magnetic field from the linear motor is applied to the bogie or not. When the transport device is configured so as to be changeable, a stable floating of the carriage can be maintained even when a large driving force or braking force is applied.

Therefore, according to the present invention, a transmitter is provided on the magnetic rail before and after the linear motor, and a bogie is provided with a receiver capable of receiving a signal from the transmitter before and after each levitation controller, and the receiver. And a gain adjuster (CPU) capable of switching the gain in accordance with the received signal, and further transmitting the gain switched by the gain adjuster to the levitation electromagnet via each conventional levitation control unit. I have.

Therefore, a driving device having a high working efficiency such that a driving force or a braking force by a linear motor, that is, a magnetic field generation capability can be used within a large range, and as a result, a high speed can be obtained in a short time. can do.

[0020]

FIG. 1 is a perspective view similar to FIG. 3, illustrating the transfer method of the present invention together with its apparatus configuration, and FIG. 2 is a diagram showing a circuit configuration relating to the transfer apparatus of FIG.

Note that FIG. 1 is based on the case of the transfer apparatus described with reference to FIG. 3, so that FIGS.
The same symbols are given to the same target members / parts as in FIG. 4 and FIG.

In FIGS. 1 and 2, on one side of the magnetic rail 1 described with reference to FIG. 3, two linear motors 1d _-1 , 1d _-2 ... The first transmitter 11 and the second transmitter 12 attached to the lower ends of the arms 11a and 12a suspended and fixed from the ceiling, the first transmitter 11 transmits the front side when the traveling direction of the bogie is A. The transmitter 11 and the transmitter 12 are disposed as connected to a linear motor control unit 13, and each of the transmitters 11 and 12 has an upper surface 21a of a bogie 21 described later floating above the magnetic rail 1 while maintaining a regular gap. It is located almost corresponding to.

On the upper surface 21a of the trolley 21 having the same configuration as the trolley 2 of FIG. 3, the four levitation electromagnets 3, the state detection unit 4, and the levitation control unit 5 described with reference to FIG. The first and second transmitters 11 and 12 corresponding to the first and second transmitters 11 and 12 are provided at two positions in the front and rear directions along the rail near the transmitter-side end of the upper surface 21a. The second receivers 22 and 23 are disposed with the leading end side in the traveling direction of the bogie as a first receiver 22, and a CPU 24 as a gain adjuster is provided between the first and second receivers 22 and 23. Are located.

Each of these electronic devices is connected to the upper surface 21a.
3 is connected to a battery (not shown) mounted on the camera as in the case of FIG. Then, the fixed first and second transmitters 1 located on the magnetic rail 1 side
1 and 12 and the first on the carriage 21 moving with respect to the magnetic rail 1
And the second receivers 22 and 23 are the first transmitter 11 fixed near the linear motor located at a position corresponding to the transport distance of the transported object from the first receiver 22 of the carriage 21. At the point in time, the operation start signal of the linear motor and the acceleration / deceleration mode corresponding thereto are transmitted from the linear motor control unit 13 connected to each transmitter, and the second transmitter 12 and the bogie near the linear motor are transmitted. The operation of the linear motor and the transmission of the mode signal are stopped when the second receiver 23 faces the second receiver 23.

The first receiver 22 converts a plurality of received mode signals into a command for switching a feedback gain for each signal, and converts the received signal into a CPU 24 as a gain adjuster.
To be delivered to

Further, the CPU 24 serving as a gain adjuster can transmit a control constant (gain) corresponding to a mode based on a command transmitted from the first receiver 22 to the above-mentioned conventional levitation controller 5. It is configured with functions.

Therefore, the linear motor at a required position is automatically applied to the moving bogie 21 to automatically move the bogie 21.
The feedback gain for 21 can be automatically switched, and the levitation in a stable state can be maintained.

After the second transmitter 12 fixed to the rail and the second receiver 23 on the carriage 21 face each other, that is, after the operation stop signal of the linear motor is transmitted to the CPU 24, The carriage 21 floats with a normal gain (K _{1 to} K ₂ ).

Therefore, in the transport apparatus having such a configuration, the floating gain of the carriage 21 can be switched when the linear motors 1d- ₁ , 1d- ₂ ,... , A stable levitation can be maintained, and an improvement in productivity by high-speed conveyance can be realized.

[0030]

As described above, according to the present invention, it is possible to provide a magnetic levitation transporting apparatus which improves the productivity by transporting the transporting member at a high speed in a stable state.

In the description of the present invention, the case where one linear motor is mounted between two transmitters on the magnetic rail is taken as an example, but a plurality of linear motors are connected between the two transmitters. By mounting the trolley on the trolley, it is possible to achieve more efficient transportation of the trolley, and consequently, the transport of the transported object.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a transport method of the present invention together with its apparatus configuration.

FIG. 2 is a diagram showing a circuit configuration related to the transport device of FIG. 1;

FIG. 3 is a view for explaining a conventional transport method together with its apparatus configuration.

FIG. 4 is a diagram showing a circuit configuration related to a conventional transport device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Magnetic rail 1d- ₁ , 1d- ₂ , ... Linear motor 3 Electromagnet for levitation 4 State detection part 5 Floating control part 6 Secondary conductor 8 Carrier 11 First transmitter 12 Second transmitter 11a, 12a Arm 13 Linear Motor controller 21 Cart 21a Upper surface 22 First receiver 23 Second receiver 24 CPU (gain adjuster)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ identification code FI B61D 27/00 B61D 27/00 SH02P 7/00 101 H02P 7/00 101K (58) Investigated fields (Int.Cl. ⁷ , (DB name) B60L 13/03-13/10

Claims (4)

(57) [Claims] 1. A linear motor (1d-1, 1d-2, ...) is provided.
The specified gap is maintained with respect to the magnetic rail (1)
So as to be able to move along the magnetic rail (1)
At least the levitation electromagnet (3) and the levitation electromagnet (3) are controlled.
Leaving the levitation controller (4) and the above linear motor
A magnetic field generates an attractive force or a repulsive force against the linear motor.
Place a trolley (21) with a secondary conductor (6) to be
The bogie (21) generates the required magnetic field from the linear motor and
That transports along the magnetic rail (1) with a predetermined gain
A floating conveyance method, Gain change to the levitating electromagnet (3) during bogie acceleration / deceleration
A magnetic levitation transport method, which comprises delivering a command. 2. A position corresponding to the linear motor arrangement position.
Before and after the installation, the first motor connected to the linear motor controller (13)
And second transmitters (11, 12) are arranged on the bogie.
The first corresponding to each of the transmitters (11, 12) is located near the electromagnet (3).
And a second receiver (22, 23) The first transmitter (11) and the first receiver (22) faced
The predetermined gain for the levitating electromagnet (3) is changed according to the position.
To change The second transmitter (12) and the second receiver (23) faced
At the position, the gain for the levitating electromagnet (3) is
2. The magnetic levitation transport according to claim 1, wherein
How to send. 3. A linear motor (1d-1, 1d-2,...) Is provided.
Magnetic rail (1) and the specified magnetic rail (1).
Move along the magnetic rail (1) while maintaining the gap amount of
At least the levitation electromagnet (3) and the levitation
Levitation controller (4) that controls the electromagnet (3) with a predetermined gain
And the magnetic field from the linear motor
The secondary conductor (6) that generates suction or repulsion
Magnetic levitation transfer device comprising a trolley (21) equipped with
And Gain change to the levitating electromagnet (3) during bogie acceleration / deceleration
Characterized by having a gain adjuster (24) capable of delivering commands
Magnetic levitation transfer device. 4. A device provided near the magnetic rail (1).
Transmitters (11, 12) and the trolley (21)
Receivers (22, 23) corresponding to the e, The gain adjuster (24) receives a signal from the receiver (22, 23).
Delivering the gain change command based on
The magnetic levitation transfer device according to claim 3.