Track cleaning device

Abstract

To provide a track cleaning device capable of cleaning a track on which a transport vehicle travels in a clean room by collecting dust deposited on the track without stopping the operation of the clean room or a transport system.SOLUTION: A track cleaning device for cleaning a track on which a transport vehicle travels in a clean room includes a traveling vehicle that travels along the track, and dust collecting means for collecting dust deposited on the track.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a track cleaning device, and more particularly to a transport vehicle that transports objects such as FOUPs installed in clean rooms in semiconductor manufacturing plants on a track, and a transport facility including the transport vehicle. [Background technology]

[0002] In semiconductor manufacturing plants, for example, the process of manufacturing semiconductor wafers is carried out in clean rooms where temperature and humidity are controlled and foreign matter (particles) of a few microns in size are removed, because contamination from the clean room environment reduces product yield. In clean rooms, temperature- and humidity-controlled air taken in by an outside air conditioner is passed through an Ultra Low Penetration Air (ULPA) filter before being supplied to the work area. If the cleanliness of the work area needs to be controlled even more strictly, a chemical filter can be added to remove chemical contaminants and supply even purer air to the work area.

[0003] Meanwhile, in the semiconductor manufacturing process, wafers are transported and stored in sealed containers called FOUPs (Front Opening Unified Pods). In clean rooms, many products come and go during the manufacturing process, and products before and after being placed in manufacturing or inspection equipment for processing are stored in stockers that store these FOUPs. To reach the stocker and processing equipment, a transport vehicle in an overhead hoist transport (OHT) system moves along a track (rail) installed in the ceiling of the clean room, hanging vertically from the track, and transports and transfers between the stocker and processing equipment. These OHT systems transport FOUPs between the stocker and equipment without stopping at all times.

[0004] Patent Document 1 describes a three-dimensional installation means for transport and transfer means such as processing equipment, carrier stockers, and OHTs in a clean room.

[0005] Patent Document 2 describes a gripper that prevents the transport means from falling due to OHT and is easy to maintain.

[0006] Patent Document 3 describes a sensor in an OHT that reliably detects obstacles while the vehicle is traveling. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2001-267195 A [Patent Document 2] JP 2012-015420 A [Patent Document 3] JP 2012-079153 A Summary of the Invention [Problem to be solved by the invention]

[0008] Because the OHT system is also in operation while the clean room is in operation, it is difficult to clean the dust that has accumulated on the tracks (rails), and cleaning could only be done when the clean room and OHT system were stopped (about once every 1-2 years). In addition, the transport vehicles in the OHT system are driven by electricity supplied from electric wires laid on the tracks, and since the wires are supplied with high voltage electricity and are exposed, workers had to perform cleaning work after turning off the power. In addition, because the tracks in the OHT system are laid near the ceiling of the clean room, workers had to work at a high altitude when performing cleaning work, which was dangerous and time-consuming work.

[0009] The present invention has been made to solve the above problems, and has an object to provide a track cleaning device that can collect dust that has accumulated on the track along which a transport vehicle runs within a clean room and clean the track without having to stop the operation of the clean room or the transport system. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention provides a track cleaning device for cleaning a track along which a transport vehicle runs in a clean room, comprising: A traveling vehicle that travels along the track; a dust collecting means for collecting dust accumulated on the track; The present invention provides a track cleaning device comprising:

[0011] Such a track cleaning device can collect dust that has accumulated on the track while traveling along the track in a clean room, so that dust that has accumulated on the track can be collected and the track in the clean room cleaned without having to stop operation of the clean room or conveying system.

[0012] Furthermore, even if the track to be cleaned is installed near the ceiling of a clean room, the track cleaning device of the present invention eliminates the need for workers to clean it directly, eliminating the dangers associated with working at heights and significantly shortening the working time of workers.

[0013] For example, the dust collecting means may include a roller-shaped brush or sponge that contacts the track and collects dust on the track, and a dust collector that sucks up the collected dust.

[0014] Such a track cleaning device can more efficiently collect dust that has accumulated on the track.

[0015] Alternatively, the dust collecting means may be an adhesive roller.

[0016] Such a track cleaning device makes it possible to collect dust accumulated on the track more easily and at low cost. Effect of the Invention

[0017] As described above, the track cleaning device of the present invention can collect dust that has accumulated on the track along which the transport vehicle runs within the clean room, and can easily clean the track within the clean room, without having to stop the operation of the clean room or the transport system. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic side view showing a first embodiment of a track cleaning device of the present invention. [Diagram 2] FIG. 2 is a schematic front view of the track cleaning device shown in FIG. [Diagram 3] FIG. 2 is a schematic side view showing a second embodiment of the orbital cleaning device of the present invention. [Figure 4] FIG. 11 is a schematic side view showing a third embodiment of a track cleaning device of the present invention. [Diagram 5] FIG. 1 is a schematic diagram showing an example of the positional relationship between an OHT system, a processing device, and an EFEM in a clean room. [Figure 6] FIG. 1 is an explanatory diagram showing an example of a general FOUP. [Figure 7] FIG. 1 is a schematic diagram showing an example of an OHT system in a clean room. [Figure 8] FIG. 11 is a schematic diagram showing another example of an OHT system in a clean room. [Figure 9] FIG. 1 is a schematic diagram of a FOUP before transfer from the OHT system to the EFEM. [Figure 10] FIG. 13 is a schematic diagram of a FOUP during transfer from the OHT system to the EFEM. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] As described above, there has been a need for the development of a track cleaning device that can collect dust that has accumulated on the track along which the transport vehicle runs within the clean room and clean the track without having to stop the operation of the clean room or the transport system.

[0020] In order to solve the above problems, the present inventors have conducted extensive research into a method and device for cleaning dust accumulated on the track along which a vehicle (transport vehicle) of an OHT system in a clean room in a semiconductor factory moves, while the clean room and OHT system are still in operation. As a result, they have found that if the vehicle (traveling vehicle) of the OHT system is provided with a dust collecting means (for example, a combination of a brush or sponge that collects dust and a dust collector that sucks up the dust, or an adhesive roller, etc.), it is possible to collect dust while traveling along the track, and have completed the present invention.

[0021] That is, the present invention is a track cleaning device for cleaning a track along which a transport vehicle runs in a clean room, A traveling vehicle that travels along the track; a dust collecting means for collecting dust accumulated on the track; The track cleaning device is characterized by comprising:

[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to these.

[0023] In the following, a track cleaning device for cleaning the tracks of an OHT system in a clean room will be described as an embodiment of the present invention. First, the configuration of the OHT system according to this embodiment will be described.

[0024] FIG. 5 is a side view showing an example of the positional relationship between the OHT transport system according to the present embodiment and the processing equipment and an EFEM (Equipment Front End Module).

[0025] The OHT system 2 shown in FIG.

[0026] The track 21 is laid on the ceiling of the clean room 100, and is made of metal such as stainless steel or aluminum from the viewpoint of strength in order to support the running part 31 of the transport vehicle 3 and the main body 32 containing the FOUP 4 shown in Fig. 6. The shape of the track 21 can be, for example, two rails with an L-shaped cross section facing each other as shown in Fig. 7, or a cross-sectional structure with a mouth-shaped lower part partially cut out as shown in Fig. 8.

[0027] The transport vehicle 3 is arranged on a track 21, and is capable of transporting a FOUP 4, which is an object to be transported, by traveling on the track 21. Although not shown in the figure, shelves (stockers) for storing the FOUP 4 are provided at positions along the track 21.

[0028] The transport vehicle 3 is made up of a running section 31 and a main body 32. The main body 32 is suspended from the running section 31 by supports 33 arranged between the two tracks 21. The main body 32 is equipped with a FOUP gripper 34. The transport vehicle 3 starts with a FOUP 4 contained within the main body 32 as shown in FIG. 9, and then, as shown in FIG. 10, the lifting belt 35 is unwound from the main body 32, and the FOUP 4 is placed on the stand 51a of the EFEM 5.

[0029] The EFEM 5 is connected to a processing device 6. The EFEM 5 and the processing device 6 will be described later.

[0030] Next, the travel of the transport vehicle 3 on the track 21 will be described. The transport vehicle 3 arranged on the track 21 travels with the running part 31 placed on the track 21 and the main body 32 suspended from the track 21. When traveling, the resin wheels 31a arranged on the running part 31 come into contact with the track 21, and dust is generated by scraping off the wheels 31a due to friction, and this dust accumulates on the track 21. In addition, air is circulated within the clean room 100, and a very small amount of dust is also contained and accumulates on the track 21.

[0031] The present invention has been made in consideration of the above-mentioned problems. Below, several embodiments of the present invention will be given to describe a method and device for cleaning dust accumulated on the track 21 while traveling on the track 21.

[0032] (First embodiment) Fig. 1 is a schematic side view of a track cleaning device according to a first embodiment, and Fig. 2 is a schematic front view from viewpoint II in Fig. 1. In Figs. 1 and 2, the track cleaning device 1 according to the first embodiment is composed of a traveling vehicle 11, a main body 13, and dust collecting means 12. The traveling vehicle 11 travels on a track 21 by means of wheels 11a arranged on the front, rear, left and right sides of the traveling vehicle 11, and the driving force for traveling is obtained from a motor (not shown) arranged in the traveling vehicle 11. It is driven by obtaining electric power from an electric wire (not shown) placed on the track 21 as a power source.

[0033] Furthermore, the central lower part of the traveling car 11 has a structure in which it is partially open between it and the track 21, and a roller-shaped track dust cleaning brush 12a is disposed in this open position, and the brush 12a rotates in contact with the track 21 in accordance with the movement of the traveling car 11 on the track 21, collecting dust accumulated on the track 21 from the tracks 21 on both sides into the central space between them. The brush 12a can collect dust more efficiently if it is structured so that the spirally formed unevenness rotates in a direction that collects dust into the central space.

[0034] The brush 12a may be made of a resin, for example. The brush 12a may be made of a sponge (for example, a resin sponge), but a brush is preferable because of its resistance to friction with the track 21 and its ability to deal with unevenness.

[0035] Furthermore, since there is a possibility that the brush 12a may come into contact with an electric wire that is a power source arranged on the track 21, the material of the brush 12a is preferably an insulating material.

[0036] The main body 13 is suspended from the traveling vehicles 11 arranged on the two tracks 21 by a support 14 arranged between the two tracks 21. A dust collector 12b, which is a device for collecting dust, is arranged inside the main body 13. Furthermore, a suction port 12c of the dust collector 12b penetrates the support 14 connecting the traveling vehicles 11 and the main body 13, and sucks up dust collected in the center of the track 21 by the brush 12a below the traveling vehicles 11. In other words, the brush 12a and the dust collector 12b constitute the dust collecting means 12.

[0037] Since the OHT system according to this embodiment operates in a clean room, it is preferable that the air exhausted from the dust collector 12b be exhausted after removing dust therefrom using a ULPA (Ultra Low Penetration Air) filter.

[0038] Furthermore, as shown in Figures 1 and 2, cameras 11b may be placed in front of and behind the traveling vehicle 11 to photograph the presence or absence of dust on the track 21 and enable monitoring by a wireless system, making it possible to confirm whether the track cleaning device 1 is able to clean the dust on the track 21.

[0039] Second embodiment FIG. 3 is a side view of a track cleaning device according to the second embodiment. In FIG. 3, the track cleaning device 1 according to the second embodiment is composed of a traveling vehicle 11, a main body 13, a cleaning vehicle 15, and a dust collecting means 12. In the first embodiment, the traveling vehicle 11 is provided with both a function for traveling on the track 21 and a function for cleaning, but in the second embodiment, in the case where there is insufficient space for these functions, the traveling vehicle 11 and the cleaning vehicle 15 are separated, and the traveling vehicle 11 cleans the track 21 by pulling the cleaning vehicle 15. It is preferable to have the same configuration as the first embodiment except for the above.

[0040] (Third embodiment) FIG. 4 is a side view of a track cleaning device according to a third embodiment. In FIG. 4, the track cleaning device 1 according to the third embodiment is composed of a traveling vehicle 11 and a dust collecting means. In the first embodiment, a main body 13 is hung from the traveling vehicle 11, and a dust collector 12b having a dust collecting function for cleaning the inside of the main body is arranged, but in the third embodiment, in order to make a configuration that is simpler and less costly, an adhesive roller 12d is used as the dust collecting means instead of the brush in the traveling vehicle 11, and the dust collector is omitted, making it possible to collect dust on the track 21 easily and at low cost. It is more preferable to replace this adhesive roller 12d periodically.

[0041] The track cleaning device 1 according to the first to third embodiments described above can collect dust accumulated on the track 21 while traveling along the track 21 in the clean room 100, so that the dust accumulated on the track 21 can be collected and the track 21 in the clean room 100 can be cleaned without stopping the operation of the clean room 100 or the OHT system 2.

[0042] Furthermore, by using the track cleaning device 1 according to the first to third embodiments, it is no longer necessary for workers to directly clean the track 21, eliminating the dangers associated with working at heights and significantly shortening the working time of workers.

[0043] Here, the FOUP 4 transported by the OHT system 2 described with reference to FIG. 5 and FIGS. 7 to 10 will be described with reference to FIG.

[0044] FOUP4 in Figure 6 is a sealed storage container for storing wafers. FOUP4 comprises a container body 41 and a lid 42. The container body 4 is formed so as to be able to store multiple wafers, and has an opening at the front. Wafers are inserted and removed through this opening. In Figure 6, the front of the container body 41 is the right side. The lid 42 is for opening and closing the opening at the front of the container body 41. When the lid 42 is closed via a packing (not shown), the inside of the container body 4 is sealed.

[0045] 5 and 7 to 10 show a case where wafers W are stored and transported in the FOUP 4. Usually, the FOUP 4 is fully filled with wafers W. Note that although the number of wafers W that is fully filled is usually, for example, 25, the drawings show only 8 wafers for the sake of simplicity.

[0046] In the above, the FOUP 4 has been described as an example of the object to be transported by the OHT system 2, but the object to be transported is not limited to a FOUP. The object to be transported may also be, for example, a sealed storage container of the FOSB (Front Opening Shipping Box) type.

[0047] Furthermore, the wafers W stored in the FOUP or FOSB are not particularly limited, and examples thereof include various semiconductor wafers such as semiconductor silicon wafers and compound semiconductor wafers, and in particular may be polished silicon wafers or silicon wafers formed by epitaxial growth. In addition, wafer-like objects such as glass substrates can also be transported.

[0048] Next, the EFEM 5 and the processing device 6 shown in Figs. 5, 9 and 10 will be described.

[0049] The EFEM 5 transfers the wafer W stored in the FOUP 4 from the FOUP 4 to the processing device 6 in a mini-environment system. The EFEM 5 includes a transfer robot 52, a transfer chamber 53, and a load port 51.

[0050] The transfer robot 52 is for taking out and transferring the wafer W stored in the FOUP 4. The transfer robot 52 can also put the wafer W in the FOUP 4 and store it therein.

[0051] The transfer chamber 53 houses a transfer robot 52. The wafer W taken out of the FOUP 4 by the transfer robot 52 is transferred to the processing device 6 via the transfer chamber 53. Conversely, the wafer W processed in the processing device 6 can be transferred and placed in the FOUP 4 via the transfer chamber 53. A wafer transfer entrance 54 for transferring the wafer W to and from the FOUP 4 is provided in the wall of the transfer chamber 53.

[0052] The load port 51 is an interface for transferring the wafer W between the FOUP 4 and the transfer chamber 53. The wafer W is transferred between the FOUP 4 and the transfer chamber 53 via the load port 51.

[0053] The load port 51 includes a load port stand (stand) 51a and a load port door (door) 51b.

[0054] 5 and 10, the stand 51a is a place on which the FOUP 4 is placed. The height and position are adjusted so that the FOUP 4 can be placed with its lid 42 facing the wafer loading / unloading opening 54.

[0055] The door 51b is for opening and closing the wafer loading / unloading entrance 54. That is, the door 51b can be fitted into the wafer loading / unloading entrance 54 and can close the opening. Moreover, the door 51b can be removed from the wafer loading / unloading entrance 54 and can open the opening. Figures 5, 9, and 10 show a state in which the opening of the wafer loading / unloading entrance 54 is closed by the door 51b.

[0056] The processing device 6 processes the wafer W transferred thereto.

[0057] The present invention is not limited to the above-described embodiment. The above-described embodiment is merely an example, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits similar effects is included in the technical scope of the present invention. [Explanation of symbols]

[0058] 1...track cleaning device, 2...OHT system, 3...transport vehicle, 4...FOUP, 5...EFEM, 6...processing device, 11...traveling vehicle, 11a...wheel, 11b...camera, 12...dust collection means, 12a...track dust cleaning brush, 12b...dust collector, 12c...suction port, 12d...adhesive roller, 13...main body, 14...support, 15...cleaning vehicle, 21...track, 31...traveling part, 31a...wheel, 32...main body, 33...support, 34...FOUP gripping part, 35...lifting belt, 41...container body, 42...lid, 51...load port, 51a...frame, 51b...door, 52...transport robot, 53...transport room, 54...wafer loading / unloading entrance, 100...clean room, W...wafer.

Claims

[Claim 1] A track cleaning device for cleaning a track along which a transport vehicle runs in a clean room, comprising: A traveling vehicle that travels along the track; a dust collecting means for collecting dust accumulated on the track; The present invention provides the dust collecting means includes a roller-shaped brush that contacts the track and collects dust on the track, and a dust collector that sucks up the collected dust, The track cleaning device is characterized in that the roller-shaped brush has a structure that rotates the spirally formed unevenness in a direction that collects the dust into the space at the center of the track.

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