JPH0586931U - Magnetic levitation slider - Google Patents

Abstract

(57) [Summary] [Object] The main feature of the present invention is to provide a magnetic levitation slider capable of preventing deformation of mechanical parts due to temperature change. [Structure] A levitation electromagnet 11 and a gap sensor 12 are housed in a frame 13 so as to face a rail 21, and the open surface of the frame 13 is sealed with a non-magnetic thin metal plate 14 and is passed through the side surface of the frame 13. The pores 4 are formed, the filter 41 is provided there, and even if the temperature inside the frame 13 rises due to the heat generated from the electromagnet 11 and the pressure rises, air is discharged through the vent holes 4.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a magnetic levitation slider, and more particularly to a magnetic levitation slider which is provided in a clean room of the semiconductor manufacturing industry and which carries a semiconductor wafer while magnetically levitating on a rail.

[0002]

[Prior Art]

 The magnetic levitation slider runs while being magnetically levitated against the laid rail by the magnetic force of an electromagnet. Since it is completely non-contact, dust due to contact wear does not occur. However, in reality, the coil of the electromagnet, the electronic components mounted on the printed circuit board, the battery, and the like are attached to the main body of the slider in an exposed state. For this reason, an organic gas (carbon dioxide gas) is generated from electronic parts and the like, which may cause a chemical reaction on the surface of the silicon wafer to form a film. That is, silicon reacts with carbon dioxide gas to form a SiC film on the surface of the silicon wafer. This coating cannot be easily removed by washing.

[0003]

[Problems to be solved by the device]

 In order to prevent the organic gas generated from the above electronic parts from being emitted into the atmosphere, the mounting parts such as electromagnets and printed circuit boards are housed in the frame, and the open surface of the frame is made non-magnetic. It is possible to seal with a thin metal plate. However, the electromagnet may generate heat due to the flow of current, and the temperature inside the sealed frame may rise, causing the thin metal plate covering the open surface of the frame to expand. As a result, the metal plate may come into contact with the rail, or the metal plate may be deformed to form a gap between the metal plate and the frame, and the organic gas may leak into the atmosphere.

Therefore, a main object of the present invention is to provide a magnetic levitation slider capable of preventing deformation of mechanical parts due to temperature change.

[0005]

[Means for Solving the Problems]

 The present invention relates to a magnetic levitation slider that travels while magnetically levitating against a laid rail, a box-shaped frame with an open top surface, a gap sensor and an electromagnet installed inside the frame so as to face the rail. And a non-magnetic thin metal plate that covers the open surface of the frame, a ventilation hole is formed in a part of the frame, and a filter is provided in the ventilation hole.

[0006]

[Action]

 In the magnetic levitation slider according to the present invention, the open surface of the frame accommodating the gap sensor and the electromagnet is covered with a non-magnetic thin metal plate, a ventilation hole is formed in a part of the frame, and a filter is provided in the ventilation hole. Since the electromagnet heats up, the temperature inside the frame rises, and the pressure inside the frame rises, it can be released to the outside through the ventilation hole.Because the ventilation hole is equipped with a filter, organic gas can be released into the atmosphere. There is no danger of being released inside.

[0007]

【Example】

 FIG. 1 is a vertical sectional view of an embodiment of the present invention. Referring to FIG. 1, a pair of rail mounting portions 22 and 22 having an L-shaped cross section are provided so as to face each other, and levitation rails 21 and 21 are mounted downward at the respective tip portions.

The slider 1 includes a box-shaped frame 13 having an open upper surface. In the frame 13, levitation electromagnets 11 and 11 and gap sensors 12 and 12 are provided so as to face the levitation rails 21 and 21, respectively. It is provided. In the space 17 in the frame 13, a printed circuit board, a battery, etc., on which electronic circuits for control are mounted, which are not shown, are stored. A non-magnetic thin metal plate 14 is attached to the open surface of the upper portion of the frame 13, and is firmly fixed to the upper surfaces of the frame 13 and the levitation electromagnet 11 by a set screw 15. In addition, on the upper part of the frame 13, a loading tray 16 on which a silicon wafer or the like is placed is provided.

Further, a vent hole 4, which is a feature of the present invention, is formed on the side surface of the frame 13, and a filter 41 is provided therein. The air in the frame 13 expands due to the heat generated from the levitation electromagnet 11 due to the temperature rise, and when the pressure in the frame 13 rises to the atmospheric pressure or higher, the air in the frame 13 causes the air in the vent 4 to move. The filter 41 adsorbs the molecules of the organic gas and prevents the gas from leaking into the atmosphere, thereby preventing air pollution in the clean room. As the filter 41, for example, activated carbon is used.

[0010]

[Effect of the device]

 As described above, according to the present invention, the levitation electromagnet and the gap sensor are housed in the frame, the open surface of the frame is sealed with the non-magnetic thin metal plate, and the ventilation hole is formed in a part of the frame. At the same time, since a filter is provided there, even if the pressure inside the frame rises due to the temperature rise, the air inside the frame can be released into the atmosphere through the ventilation holes, and at that time, the molecules of the organic gas are filtered by the filter. As it is adsorbed, it does not pollute the atmosphere.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 slider 4 vent hole 11 electromagnet 12 gap sensor 13 frame 14 metal thin plate 15 set screw 16 load carrier 21 levitation rail 22 rail mounting portion 41 filter

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location H01L 21/68 A 8418-4M

Claims (1)

[Scope of utility model registration request] 1. A magnetic levitation slider that travels while magnetically levitating with respect to a laid rail, and a box-shaped frame having an open upper surface, and a frame provided so as to face the rail. A gap sensor that detects a gap with a rail, an electromagnet that is provided in the frame so as to face the rail and that magnetically levitates the frame, and covers the open surface of the frame, and the rail and the gap sensor. And a non-magnetic thin metal plate for partitioning the electromagnet from each other, wherein a ventilation hole is formed in a part of the frame, and a filter is provided in the ventilation hole.