Linear transfer device and storage box for linear transfer device

Abstract

To provide a configuration in which a function for detecting a movable element is hard to damage even if implementation of vacuum processing is repeated in a vacuum chamber in a linear transfer device LM which transfers a substrate Sg along a transfer path Tp in the vacuum chamber extending in one direction.SOLUTION: A linear transfer device comprises: a movable element 1 including a transfer plate 11 in which a substrate is installed on one face and a plurality of permanent magnets 12 which is disposed in an equal pitch while making magnetic poles alternately different on the other face of the transfer plate; a plurality of stators 2 disposed along a transfer path while being opposed to the movable element; and magnetism sensitive elements 31 and 32 which are sensitive to magnetic fields generated by the mutually adjacent permanent magnets. A storage box 5 is disposed in a vacuum chamber, and the stators and the magnetism sensitive elements are provided in the storage box which is atmospherically separated from the vacuum chamber. The magnetism sensitive elements are disposed on front and rear sides of the stators in one direction, and the presence / absence of the movable element is discriminated.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a linear transport device for transporting a workpiece along a transport path within a vacuum chamber that extends in one direction, and a storage box for the linear transport device. [Background technology]

[0002] One such linear conveyance device is described in Patent Document 1. This device includes a conveyance plate on one side of which a workpiece is placed, a mover having multiple permanent magnets arranged at equal intervals with alternating magnetic poles on the other side of the conveyance plate, and multiple stators arranged along the conveyance path facing the mover. The device also includes magnetically sensitive elements (Hall elements) that detect the magnetic fields generated by adjacent permanent magnets, and the position of the mover can be recognized based on the magnetic fields detected by the magnetically sensitive elements. Specifically, the Hall elements detect the magnetic field generated between the permanent magnets at the front end of the moving mover in the conveyance direction, and the position of the mover is recognized based on this. In this case, a detection piece is provided on the mover, and a sensor that detects the detection piece is provided at a predetermined position on the conveyance path. The sensor determines the presence or absence of the conveyance plate, and the detected position of the detection piece is converted into the actual position of the mover, allowing the position of the mover to be recognized with high accuracy.

[0003] The linear transport device is also used in so-called in-line vacuum processing equipment, which transports large-area substrates, such as glass substrates, in a vertical position with their processing surfaces facing horizontally through a series of processing chambers (vacuum chambers) arranged in a vacuum atmosphere in one direction, and performs various vacuum processes, such as film formation and etching, on the processing surfaces. In this case, the sensor described above must also be placed in the vacuum chamber. However, repeated vacuum processing within the processing chamber can cause contamination within the processing chamber due to the adhesion of film formation materials and reaction products, and if the detection piece and sensor also become contaminated, the detection accuracy of the sensor can be reduced. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5887821 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above, an object of the present invention is to provide a linear conveying device and a storage box for a linear conveying device that are configured so that the function of detecting the movable element is less likely to deteriorate even when vacuum processing is repeatedly performed within the processing chamber. [Means for solving the problem]

[0006] To achieve the above object, the present invention provides a linear transport device for transporting workpieces along a transport path within a vacuum chamber extending in one direction, the linear transport device comprising: a transport plate on one side of which the workpiece is placed; a mover having a plurality of permanent magnets on the other side of the transport plate with alternating polarities and arranged at equal intervals; a plurality of stators arranged along the transport path facing the mover; and a magnetically sensitive element sensitive to the magnetic fields generated by adjacent permanent magnets, the linear transport device comprising: a storage box disposed within the vacuum chamber, the storage box being atmospherically isolated from the vacuum chamber; the stator and the magnetically sensitive element are housed within the storage box; the magnetically sensitive element is disposed at least in front of or behind the stator, the stator having at least one coil set consisting of a plurality of electromagnetic coils to which currents out of phase with each other are respectively passed, and configured to detect the mover. In this case, the storage box comprises a box portion having an open surface facing the mover and a lid portion covering the open surface of the box portion, the lid portion being made of a paramagnetic material having mechanical strength, such as titanium or molybdenum. Furthermore, a detection element such as a magnetic encoder for detecting the position of the mover may also be placed between the magnetically sensitive elements and stored in the storage box.

[0007] According to the present invention, since the stator and magnetic sensing element are housed in a storage box, repeated vacuum processing within the vacuum chamber does not result in a problem such as a decrease in the ability to detect the mover (i.e., the ability to determine the presence or absence of the mover) due to contamination of the magnetic sensing element. Furthermore, since the lid is made of a paramagnetic material, the ability of the magnetic sensing element to sense the magnetic field generated by the permanent magnet is not impaired even when it is housed in the storage box. For example, if the transport plate is configured to reciprocate forward and backward in one direction when transporting workpieces along the transport path within the vacuum chamber, it is preferable to arrange magnetic sensing elements in front of and behind the stator in one direction. Regardless of whether they are housed in the same storage box, when the magnetic sensing elements in front of and behind the stator in one direction sense (detect) the magnetic fields generated by the adjacent permanent magnets of the mover, it can be determined that the stator is directly facing the transport plate. By energizing the stator (coil set) accordingly, the transport plate can be moved smoothly. If detecting elements are also stored in the storage box, positioned between the magnetically sensitive elements, the position of the transport plate on the transport path can also be detected.

[0008] In the conventional example, if components such as sensors and detection pieces are provided, they must be installed in a narrow space within the vacuum chamber, which may impair maintainability. In contrast, in the present invention, components such as the stator and magnetically sensitive elements (including detection elements in some cases) are stored in a storage box, eliminating the need to provide any components on the mover. This prevents workers from accidentally touching and damaging various components during maintenance within the vacuum chamber. This, combined with the absence of components such as sensors within the vacuum chamber, also improves maintainability. The magnetically sensitive elements can be, for example, Hall elements that detect vertical magnetic fields. In this case, for example, the distance between the centers of adjacent magnets is defined as the magnet pitch. Installing two Hall elements at a distance of 1 / 2 the magnet pitch or three Hall elements at a distance of 1 / 3 the magnet pitch advantageously enables reliable detection of the mover while the conveying plate moves directly opposite the stator.

[0009] In the present invention, a configuration may be adopted in which a ferromagnetic plate is attached to at least one of the front and rear ends of the mover. This configuration allows the magnetic field generated by the permanent magnets located at the front and rear ends to be concentrated in the ferromagnetic plate, reducing leakage to the outside. Therefore, when detecting the mover using a Hall element as a magnetic sensing element, the standard deviation of the "mover present" or "mover absent" events in a normal distribution with the horizontal axis representing the position directly facing the mover and stator can be reduced. This makes it possible to clearly ensure that the mover is located directly facing the stator, which can contribute to the design of a compact storage box, for example.

[0010] When the containment box is installed in a vacuum chamber as described above, in addition to heat generated by energizing the electromagnetic coil, radiant heat and conductive heat may also occur depending on the vacuum processing performed therein, causing the temperature inside the containment box to rise. In the present invention, if a configuration is adopted in which gas inlet and outlet paths are connected to the containment box so that the interior can be air-cooled, this is advantageous, for example, as it can extend the usage limit of the electromagnetic coil. Moreover, because the containment box is atmospherically isolated from the interior of the vacuum chamber, it does not adversely affect the vacuum processing performed in the vacuum chamber.

[0011] In addition, in order to solve the above problems, the storage box for the linear conveying device of the present invention, which is placed within a vacuum chamber in an atmosphere separated from the vacuum chamber, is characterized in that it contains a stator having at least one coil set consisting of a plurality of electromagnetic coils to which currents of mutually out-of-phase are respectively passed, and a magnetically sensitive element placed at least in one direction in front or behind the stator. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a cross-sectional view illustrating a part of a vacuum processing apparatus including the linear transport device of the present embodiment. [Figure 2] FIG. 2 is an enlarged cross-sectional view of the linear transport device shown in FIG. [Figure 3]FIG. 10 is an enlarged cross-sectional view of a stator according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, with reference to the drawings, an embodiment will be described taking as an example a glass substrate (hereinafter referred to as "substrate Sg") used in the manufacture of flat panel displays as a workpiece, and an in-line vacuum processing apparatus Vm that performs various vacuum processes such as film formation processes on one surface (processing surface) of the substrate Sg in an upright position, to which the linear conveyance device LM and storage box 5 of the present invention are applied. In the following, the movement direction of the substrate Sg along the conveyance path Tp (for example, movement from the left side to the right side, which is the forward movement direction in FIG. 1) is defined as the X-axis direction, the vertical direction perpendicular to the X-axis direction is defined as the Z-axis direction, and the posture in which one surface (processing surface) of the substrate Sg faces one side in the horizontal direction is defined as the upright posture.

[0014] Referring to FIG. 1, the vacuum processing apparatus Vm has a first load lock chamber Lc1 located at one end in the X-axis direction. Although not specifically shown or described, an exhaust pipe from a vacuum pump and a vent gas line for introducing vent gas are connected to the first load lock chamber Lc1, allowing the load lock chamber Lc1 to be switched between a vacuum atmosphere and an atmospheric atmosphere as needed. After a substrate Sg is placed on a carrier Tc, it is loaded into the first load lock chamber Lc1 in an upright position. The carrier Tc, the mounting structure for the substrate Sg on the carrier Tc, and the mechanism for loading the carrier Tc into the first load lock chamber Lc1 are all well-known, and therefore detailed description thereof will be omitted here.

[0015] On one side of the first load lock chamber Lc1 in the X-axis direction (the right side in FIG. 1), a number of processing chambers Pc (two processing chambers Pc1 and Pc2 are illustrated) corresponding to the various vacuum processes to be performed on the processing surface of the substrate Sg are connected via gate valves Gv. Each processing chamber Pc1 and Pc2 is equipped with devices (not shown) necessary for performing the various vacuum processes, such as evaporation sources and sputtering cathodes, and the various vacuum processes are performed on the upright substrate Sg in the vacuum atmosphere processing chambers Pc1 and Pc2. A second load lock chamber Lc2 is connected to the processing chamber Pc2 located at the other end of the X-axis direction via a gate valve Gv, allowing the processed substrate to be recovered. A linear transport device LM equipped with a storage box 5 according to this embodiment is provided to transport the substrate Sg placed on a carrier Tc along a transport path Tp extending in the X-axis direction from the first load lock chamber Lc1 through the processing chambers Pc1 and Pc2 to the second load lock chamber Lc2.

[0016] Referring also to FIG. 2, the linear transport device LM includes a mover 1, multiple stators 2 arranged at predetermined intervals along the transport path Tp facing the mover 1, magnetically sensitive elements 31 and 32 for determining the presence or absence of the mover 1 on the transport path Tp, and a detection element 4 for detecting the position of the mover 1 on the transport path Tp. In this embodiment, the stators 2, magnetically sensitive elements 31 and 32, and detection element 4 are housed in a single storage box 5 and installed in vacuum chambers Lc1, Lc2, Pc1, and Pc2 with separate atmospheres. The mover 1 includes a transport plate 11 made of a magnetic material and having a carrier Tc installed on its upper surface in the Z-axis direction. On the lower surface of the transport plate 11 in the Z-axis direction, multiple permanent magnets 12 are arranged at an equal pitch with alternating magnetic poles (in other words, the magnetic poles on the lower surface in the Z-axis direction alternate between south and north poles, so that adjacent permanent magnets 12 generate a magnetic field Mf1). Hereinafter, the center-to-center distance between the permanent magnets 12 is referred to as the magnet pitch Mp.

[0017] Ferromagnetic plates (magnetic shunts) 13 of a predetermined thickness are attached to the front and rear end faces of the transport plate 11 in the X-axis direction so as to cover the front and rear end faces of the permanent magnets 12 located at the front and rear ends, respectively, in the X-axis direction, thereby concentrating the magnetic field Mf2 generated from the permanent magnets 12 located at the front and rear ends, respectively, in the X-axis direction within the ferromagnetic plates 13 and reducing leakage to the outside. The ferromagnetic plates 13 may be made of any material that has high maximum magnetic permeability and rigidity, and examples of such materials include magnetic stainless steel such as SUS430, metals such as pure iron and nickel that can enhance the magnetic field attenuation effect, and alloys with high magnetic permeability such as permalloy and supermalloy.

[0018] The stator 2 has at least one coil set 21 consisting of multiple electromagnetic coils (three electromagnetic coils 21a, 21b, and 21c for U, V, and W phases in this embodiment), each of which is energized with a current that is out of phase with the other. Because known coils can be used for each of the electromagnetic coils 21a, 21b, and 21c, further explanation, including the power supplies for energizing them, will be omitted. The magnetically sensitive elements 31 and 32 are, for example, known Hall elements that detect vertical magnetic fields, and are positioned at the front and rear of the stator 2 in the X-axis direction. Here, if two Hall elements that detect vertical magnetic fields are positioned at the front and rear of the stator 2 in the X-axis direction, the presence of the transport plate 11 (the presence of the mover) can be detected if the Hall elements are positioned on the projection plane of the permanent magnets 12 provided on the transport plate 11. However, if the Hall elements are positioned on the projection plane between adjacent permanent magnets 12, the horizontal component of the magnetic field Mf1 generated by the permanent magnets 12 becomes dominant, and the presence or absence of the transport plate 11 may not be detected. In this embodiment, each magnetic sensing element 31, 32 is composed of two Hall elements 3a, 3b arranged in a row at a distance of 1 / 2 the magnet pitch Mp in the front and rear of the X-axis direction, and the presence or absence of the conveying plate 11 can be determined by their theoretical sum.

[0019] The detection element 4 is a known magnetic encoder that measures the amount of movement of the transport plate 11 based on changes in the magnetic field Mf1 when the transport plate 11 moves, and is located between one of the magnetically sensitive elements 31 (the rear side in the X-axis direction) and the stator 2. The storage box 5 is composed of a box section 51 with an open surface facing the mover 1 and a lid section 52 that covers the open surface of the box section 51 while maintaining an airtight seal. The lid section 52 is made of a paramagnetic material with mechanical strength, such as a titanium or molybdenum plate with a predetermined thickness. Both the magnetically sensitive elements 31 and 32 detect the transport plate 11, determining that the detection element 4 and the stator 2 are directly facing the transport plate 11. Based on this, current is passed through the coil set 21 of the stator 2, and the position of the moving transport plate 11 is detected by the detection element 4, determining the current to be passed through the coil set 21. The number of storage boxes 5 to be arranged in each of the vacuum chambers Lc1, Lc2, Pc1, and Pc2 and the spacing between them in the X-axis direction are appropriately set taking into consideration, for example, the length of the transport plate 11 in the X-axis direction.

[0020] The vacuum processing device Vm includes a control unit (not shown). The control unit is a known device including a microcomputer, a sequencer, a memory, and the like, and controls various components (such as a vacuum pump, a vacuum gauge, a gas introduction means, a heater, and a film formation unit) provided in the processing chambers Pc1 and Pc2 to perform a predetermined process. In this embodiment, the control unit also controls the operation of the linear transfer device LM. Below, an example will be described in which two storage boxes 5 are arranged at a predetermined interval in the X-axis direction in each of the vacuum chambers Lc1, Lc2, Pc1, and Pc2. (Hereinafter, the storage box 5 on the upstream side in the transfer direction (rear side in the X-axis direction) within each vacuum chamber Lc1, Lc2, Pc1, and Pc2 will be referred to as the "first box 5a," and the storage box 5 on the downstream side in the transfer direction (front side in the X-axis direction) will be referred to as the "second box 5b.") A carrier Tc (hereinafter simply referred to as the "carrier Tc") carrying a substrate Sg is transported along a transfer path Tp by the linear transfer device LM.

[0021] The transfer plate 11 is stopped at a predetermined position in the first load lock chamber Lc1, which is in an atmospheric atmosphere, and in this state, the carrier Tc is placed in an upright position on the transfer plate 11. At this time, the transfer plate 11 is detected by both the magnetic reaction elements 31, 32, which are arranged in the first box 5a and the second box 5b of the first load lock chamber Lc1, respectively, and it is determined that the detection elements 4 and stators 2 in the first box 5a and the second box 5b are directly facing the transfer plate 11. Once the carrier Tc is placed, the first load lock chamber Lc1 is evacuated, and once the vacuum is reached to a predetermined pressure, the gate valve Gv is opened to connect the first load lock chamber Lc1 to the adjacent processing chamber Pc1, which is in a vacuum atmosphere. Then, current is passed through the coil groups 21 of the stator 2 in the first box 5a and the second box 5b (i.e., currents 120 degrees out of phase are passed through the electromagnetic coils 21a, 21b, and 21c), causing the mover 1 to start moving downstream along the transport path Tp.

[0022] When the mover 1 starts to move and the transport plate 11 can no longer be detected by the magnetic reaction element 31 on the rear side in the X-axis direction (left side in FIG. 1) in the first box 5a of the first load lock chamber Lc1, it cannot be determined that the detection element 4 and the stator 2 in the first box 5a are directly facing the transport plate 11, so power to the stator 2 in the first box 5a is stopped. On the other hand, while the transport plate 11 is being detected by both the magnetic reaction elements 31 and 32 in the second box 5b of the first load lock chamber Lc1, power continues to be supplied to the coil set 21 of the stator 2 in the second box 5b, and the position of the moving transport plate 11 is detected by the detection element 4, and the current to be passed through the coil set 21 is determined. Next, as the mover 1 moves further along the transfer path, the transfer plate 11 is detected by both the front and rear magnetic sensing elements 31, 32 in the X-axis direction located in the first box 5a of the processing chamber Pc1. It is determined that the stator 2 and the detection element 4 in the first box 5a are directly facing the transfer plate 11, and current is applied to the coil set 21 of the stator 2 in the first box 5a of the processing chamber Pc1. As the transfer of the mover 1 continues, current is stopped and then applied to the stator 2 in the second box 5b of the first load lock chamber Lc1 based on the detection results of the magnetic sensing elements 31, 32. When the carrier Tc reaches a predetermined position in the processing chamber Pc1, the gate valve Gv is closed and a predetermined vacuum process is performed in the processing chamber Pc1. This process is repeated until the carrier Tc is transferred to the second load lock chamber Lc2.

[0023] According to the above embodiment, the stator 2, the magnetically sensitive elements 31, 32, and the detection element 4 are stored in the storage box 5, so there is no problem such as a decrease in the function of detecting the mover 1 due to contamination of the magnetically sensitive elements 31, 32. Furthermore, because the cover 52 is made of a paramagnetic material, the function of sensing the magnetic fields Mf1, Mf2 generated by the permanent magnets 12 is not impaired even if the magnetically sensitive elements 31, 32 are stored in the storage box 5. Therefore, when both the magnetically sensitive elements 31, 32 on the front and rear sides of the stator 2 in one direction always sense the magnetic fields Mf1 generated by the permanent magnets 12 adjacent to each other on the mover 1, it can be determined that the stator 2 and the detection element 4 are directly facing the transport plate 11. If current is applied to the stator 2 (coil set 21) accordingly, the transport plate 11 can be moved smoothly, and the position of the mover 1 can be detected by the detection element 4. Furthermore, since the stator 2, magnetic sensing elements 31, 32 and detection element 4 are stored in the storage box 5 and no parts are provided on the movable element 1, it is possible to prevent workers from accidentally coming into contact with and damaging various parts during maintenance inside the vacuum chambers Lc1, Lc2, Pc1 and Pc2, and this, combined with the fact that there are no parts such as sensors inside the vacuum chambers Lc1, Lc2, Pc1 and Pc2, also improves maintainability.

[0024] Furthermore, because the magnetically sensitive elements 31 and 32 are arranged at a distance of half the pitch Mp of the two Hall element magnets that detect the vertical magnetic field, the mover 1 can be reliably detected while the conveying plate 11 moves through the position directly opposite the stator 2, which is advantageous. Furthermore, because the ferromagnetic plates 13 are attached to the front and rear ends of the mover 1, the magnetic fields Mf2 generated by the permanent magnets 12 located at the front and rear ends are concentrated within the ferromagnetic plates, reducing leakage. Therefore, when detecting the mover 1 using Hall elements as the magnetically sensitive elements 31 and 32, the standard deviation of the "mover present" or "mover absent" events in a normal distribution with the horizontal axis representing the directly opposite position of the mover 1 and stator 2 can be reduced. This makes it possible to clearly ensure that the mover 1 is present in the position directly opposite the stator 2, which can contribute to, for example, designing a compact storage box 5. Furthermore, in experiments conducted by the inventors, it was confirmed that the positions at which the magnetic sensing elements 31 and 32 detect the movable element 1 can be made closer than when the ferromagnetic plate 13 is not present, and that the variation in the detected coordinates can be reduced by approximately 60%.

[0025] Although the above describes an embodiment of the present invention, various modifications are possible without departing from the scope of the technical concept of the present invention. In the above embodiment, two Hall elements 3a, 3b are arranged in a row at an interval of 1 / 2 the magnet pitch Mp. However, this is not limited to this. Three Hall elements can be arranged in a row at an interval of 1 / 3 the magnet pitch. Furthermore, while the above describes an example in which the Hall elements detect a vertical magnetic field, this is not limited to this. One that detects a horizontal magnetic field can also be used. Furthermore, in the above embodiment, the magnetic sensing elements 31, 32 are located in front of and behind the stator 2 in the X-axis direction within a single storage box 5. However, this is not limited to this. Although not specifically shown or described, when multiple storage boxes 5 are arranged close together in a vacuum chamber, for example, the magnetic sensing element 32 in front of the stator 2 in the X-axis direction may be omitted, and when the transport plate 11 is detected by both of the magnetic sensing elements 31, 31 behind the stators 2 in the X-axis direction of each adjacent storage box 5, it may be determined that the detection element 4 in the first box 5a and the stator 2 are directly facing the transport plate 11.

[0026] When the storage box 5 is installed in the load lock chambers Lc1 and Lc2 or the processing chambers Pc1 and Pc2 as in the above embodiment, in addition to heat generated by energizing the electromagnetic coils 21a, 21b, and 21c, radiant heat and conductive heat may be added depending on the vacuum processing performed therein, resulting in a high temperature inside the storage box 5. As shown in FIG. 3 , the modified storage box 50 located inside the processing chamber Pc1 is connected to a gas inlet path 50a and an outlet path 50b extending from outside the processing chamber Pc1. Compressed air, inert gas, etc., are introduced into the storage box 50 through the inlet path 50a and discharged through the outlet path 50b, thereby air-cooling the storage box 50. This advantageously extends the service life of the electromagnetic coils 21a, 21b, and 21c, for example. Moreover, because the storage box 50 is atmospherically isolated from the processing chamber Pc1, it does not adversely affect the vacuum processing performed therein. Furthermore, in the above embodiment, an example was given in which one magnetic sensing element 3, the detection element 4, the stator 2, and the other magnetic sensing element 3 are arranged in that order from one side in the X-axis direction. However, if the detection element 4 is configured as a magnetic encoder equipped with a Hall element, it is advantageous to have the detection element 4 also serve the role of one of the magnetic sensing elements 3, as this can improve the freedom of design of the storage box 5. [Explanation of symbols]

[0027] LM...linear conveying device, Lc1, Lc2...load lock chamber (vacuum chamber), Pc1, Pc2...processing chamber (vacuum chamber), Tp...conveying path, Sg...glass substrate (workpiece), 1...mover, 11...conveying plate, 12...permanent magnet, 13...ferromagnetic plate, 2...stator, 21...coil set (component of stator), 31, 32...magnetic sensing element, 3a, 3b...Hall element (component of magnetic sensing element), 4...detecting element, 5, 50...storage box, 50a...gas inlet path, 50b...gas outlet path, 51...box portion, 52...lid portion.

Claims

1. A linear conveyance device for conveying a workpiece along a conveyance path extending in one direction within a vacuum chamber, A moving element having a conveying plate on one side of which a workpiece is placed and a plurality of permanent magnets arranged at equal pitches with alternating magnetic poles on the other side of the conveying plate, a plurality of stators arranged along a conveying path facing the moving element, and magnetically sensitive elements that are sensitive to the magnetic fields generated by the adjacent permanent magnets, A linear conveyance device characterized in that a storage box is placed within a vacuum chamber, a stator and a magnetically sensitive element are provided within the storage box, which is atmospherically isolated from the vacuum chamber, and the magnetically sensitive element is placed at least in one direction in front or behind the stator, which has at least one coil set consisting of a plurality of electromagnetic coils to which currents out of phase with each other are respectively passed, to detect the mover.

2. 2. The linear transport device according to claim 1, wherein the storage box comprises a box portion having an open surface facing the movable element and a lid portion covering the open surface of the box portion, the lid portion being made of a paramagnetic material.

3. 3. The linear transport device according to claim 1, wherein a ferromagnetic plate is attached to at least one of the front end and the rear end of said mover in one direction.

4. 3. The linear transport device according to claim 1, wherein said storage box is connected to an inlet and outlet passages for gas so that the inside of said storage box can be air-cooled.

5. A storage box for a linear transport device that is disposed in a vacuum chamber in a state where the atmosphere in the vacuum chamber is separated from the atmosphere in the vacuum chamber, A storage box characterized in that the storage box contains a stator having at least one coil set consisting of a plurality of electromagnetic coils to which currents out of phase with each other are respectively passed, and a magnetically sensitive element arranged at least in one direction, forward or backward, of the stator.

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