JPH04171841A - Self-traveling transfer truck - Google Patents

Abstract

PURPOSE:To reduce a high-frequency vibration, which is transmitted to materials to be transferred, as the positional accuracy of the materials to be transferred subsequent to the stop of a truck main body is maintained by a method wherein the title truck is provided with the truck main body and a material-to-be- transferred retention stage, which floats on this main body by a magnetic action. CONSTITUTION:A cassette 2 with silicon substrates 1 housed therein is built in each cassette case 3 and the cassette cases 3 are installed on a cassette case retention stage 4 on a truck main body 7. A magnetically floating unit 6 is mounted to the lower part of the stage 4 and at the time of transfer of the cases 3, this unit 6 is actuated and the truck main body is made to travel on a track or the surface of a floor by the drive of the wheels of the main body in a state that the stage 4 is floated from the main body 7 and transfers the cases 3 to prescribed positions. At the time of stop of the main body, the stage 4 is returned to a prescribed position on the main body 7 by the support of guide pins 5 by making the function of the unit 6 stop. Thereby, with the transmission of a high-frequency vibration, which is generated by recesses and projections on the track or the floor surface, to the stage reduced, the positional accuracy of the wafers subsequent to the stop is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an unmanned self-propelled carrier that transports semiconductor substrates between manufacturing facilities when manufacturing semiconductor integrated circuits and the like.

[Conventional technology]

A conventional self-propelled carrier will be described with reference to FIG. 2.

FIG. 2(a) is a schematic perspective view of a conventional self-propelled transport vehicle (hereinafter abbreviated as "transport vehicle"). FIG. 2 (bl) is a perspective view showing the inside of the cassette case 13, which is the object to be transported by the transport vehicle 14 shown in FIG. 2(a).

A cassette 12 containing a silicon substrate 11 is housed in the cassette case 13. The transport vehicle 14 loads the cassette case 13, runs on a track or on the floor by driving wheels, and carries the cassette case 1 to a predetermined position.
Transport 3.

This transport vehicle 14 is equipped with an axle or a cassette case 1 to improve the positional accuracy of the cassette case 13 after it has stopped.
The structure in which the holder 3 has a cushioning material such as urethane rubber reduces vibrations transmitted to the cassette case 13 during transportation.

[Problem to be solved by the invention]

However, with the above-mentioned conventional configuration, it is not possible to sufficiently reduce high-frequency vibrations caused by unevenness of the floor surface or raceway surface during transportation, and high-frequency vibrations are imparted to the silicon substrate 11 in the cassette case 13. Defects such as cracks and chips may occur in the substrate 11.

An object of the present invention is to provide a self-propelled transport vehicle that can reduce high-frequency vibrations transmitted to the transported object while maintaining positional accuracy of the transported object after stopping.

[Means to solve the problem]

The self-propelled carrier of the present invention includes a carrier body and an object holding table which levitates magnetically above the carrier body.

[Effect]

According to the configuration of the present invention, the object holding table is made to float from the cart body by magnetic action during transportation, and the floating of the object holding table from the cart body is stopped when the cart is stopped.

〔Example〕

An embodiment of the present invention will be described with reference to FIG.

FIG. 1 is a schematic diagram showing the internal structure of a self-propelled transport vehicle according to an embodiment of the present invention from the side.

The cassette case 3 has a built-in cassette 2 containing a silicon substrate 1, and the cassette case 3 is installed on a cassette case holding stand 4 on a trolley body 7. A magnetic levitation unit 6 is attached to the lower part of the cassette case holding stand 4, and when it is operated, the cassette case holding stand 4 is levitated from the cart body 7 during transportation.
The cassette case 3 is transported to a predetermined position by running on a track or on the floor by driving the wheels. Furthermore, when the carriage is stopped, the function of the magnetic levitation unit 6 is stopped, and the cassette case holding base 4 is moved to a predetermined position on the carriage body 7 by the support of the guide pins 5.

As described above, according to this embodiment, during transportation, the cassette case holding stand 4 is in a state floating above the cart body 7, so that the cassette case holding stand 4 is free from high-frequency vibrations generated by irregularities on the track or the floor surface. The transmission to the pedestal 4 is reduced, and therefore defects such as cracks and chips that occur in the silicon substrate 1 are also reduced. Further, when the vehicle is stopped, the floating of the cassette case holding base 4 is stopped and returned to a predetermined position on the trolley body 7, so that the positional accuracy after the vehicle is stopped is maintained.

〔Effect of the invention〕

The self-propelled transport vehicle of the present invention can reduce the transmission of high-frequency vibrations generated during travel to the transported object by causing the object holding platform to float above the trolley body by magnetic action during transport. In addition, by stopping the object holding stand from floating from the trolley body when the vehicle is stopped, the positional accuracy of the object can be maintained after the vehicle has stopped.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the internal structure of a self-propelled transport vehicle according to an embodiment of the present invention from the side, Fig. 2) is a schematic perspective view of a conventional self-propelled transport vehicle, and Fig. 2 fb) is a schematic diagram showing the internal structure of a self-propelled transport vehicle according to an embodiment of the present invention. It is a perspective view showing the inside of a cassette case. 4... Cassette case holding stand, 6... Magnetic levitation unit, 7... Cart body Patent applicant Matsushita Electronics Co., Ltd. si diagram

Claims (1)

[Claims] A self-propelled transport vehicle that includes a main body of the main body and an object holding stand that levitates above the main body of the main body by magnetic action.