Suspended type transporting carriage and transporting system

A suspended type transporting carriage (16) is provided with: a gripping mechanism (22) for gripping a transported object (17); a hoisting mechanism (21) for hoisting the gripping mechanism; and a traveling mechanism (60), on which the hoisting mechanism is mounted in a suspended condition, for traveling on a rail (20) installed on or near a ceiling. The gripping mechanism is provided with (i) an elongating and contracting device (23) capable of horizontally elongating and contracting and (ii) a gripping device (24) disposed at a tip portion of the elongating and contracting device for selectively gripping the transported object.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a suspended type transporting carriages such as an OHT (Overhead Hoist Transport) carriage, which is used in a manufacturing factory of a semiconductor device, an LCD (Liquid Crystal Display) device and the like and which travels on a track installed on or near the ceiling of the factory and transports the object, as well as a transporting system using such a carriage.

2. Description of the Related Art

In a manufacturing factory of a semiconductor device, an LCD device and the like, in order to deal with an increase of production amount, an improvement in production efficiency is strongly desired, as one of which it is desired to shorten the transporting time duration. In order to shorten the transporting time duration, it becomes an important point how to shorten the time duration required to transfer a carrier (i.e., a transported object) to a stocker or stacker device, which is a temporarily storage place for the carrier, from the carriage, how to shorten the time duration required to transfer the carrier to the carriage from the stocker, and so on. Here, the “carrier” or “transported object” in the present invention means a product, an intermediate product, a part, an article, a work, a partly-finished good, a good or the like (e.g, a semiconductor or LCD device), or means a box or container for containing such a product or the like (e.g, a container containing the semiconductor or LCD device), which has been transported or is to be transported by the transporting carriage.

For example, the semiconductor integrated circuit element, which is manufactured by the semiconductor manufacturing factory, is transported by the transporting system, while various processes such as thin film formation by CVD (Chemical Vapor Deposition), ion injection, photo-lithography, etching, inspection and so forth peculiar to the semiconductor manufacturing processes, are applied to the circuit element by various processing devices so that the final product is produced. In these processes, a plurality of semiconductor substrates are stored in a container, which is so called as a “FOUP (Front-Opening Unified Pod)” The semiconductor substrates in the container are transported between the processing devices by the transporting carriage, and are subjected to the respective peculiar processes by the respective processing devices. However, the processing time durations required for the respective processes are different between the processing devices. Thus, the waiting time duration until the next process is applied to the semiconductor substrates, whose duration or length is unknown, is normally generated for the semiconductor substrates. During this waiting time duration, by the transporting device, the FOUP containing the semiconductor substrates is once transported to, and is transferred (i.e., put) into a stocker or onto a simplified rack buffer from the carriage. When such a condition that the next process can be applied comes, the FOUP containing the semiconductor substrates is transferred (i.e., picked up) from the stocker or the simplified rack buffer to the carriage again, and is transported by the transporting system to the processing device for the next process. In case that the storage place for the FOUP is the simplified rack buffer disposed at the vicinity of the respective processing devices, the transferring operations (i.e., putting and/or picking-up operations) take a short time. On the other hand, in case that the storage place for the FOUP is the stocker which is disposed distant from the processing device, the putting and/or picking up operations take a long time. Therefore, to more often employ the simplified rack buffer instead of the stocker is effective for shortening the transporting time duration. By shorting the time duration required to put and/or pick up the FOUP, the improvement in the production efficiency is expected.

Japanese Patent Application Publication Laid Open No. 2005-150129 discloses such a simplified rack buffer disposed at the vicinity of the processing device. In this case, the transferring operations to and from the simplified rack buffer can be easily performed by a hoisting belt, which is disposed on the transporting carriage, and a sliding rack plate, which is slidable in a horizontal direction. The sliding rack plate allows the movement of the FOUP toward the transporting carriage.

Each of Japanese Patent Application Publication Laid Opens No. 2005-206371 and No. 2005-530361 discloses such a simplified rack buffer disposed at the vicinity of the processing device. In this case, the sliding rack plate is not used. Instead, the hoisting mechanism itself is slidable by virtue of the sliding mechanism. The hoisting mechanism is slid between the position right underneath the traveling rail and the lateral position of the traveling rail, so that the transporting carriage can directly access the port, which is lateral from the position right underneath the traveling rail.

SUMMARY OF THE INVENTION

The above described art disclosed in Japanese Patent Application Publication Laid Open No. 2005-150129 has such a problem that, since the driving mechanism including gears, a driving motor and so forth is required to each of the sliding rack plates, the cost of the rack device becomes essentially quite high. Further, a failure in just one sliding rack plate may cause the total failure of the rack device, which certainly degrades the reliability of the rack device.

The above described art disclosed in Japanese Patent Application Publication Laid Open No. 2005-206371 or No. 2005-530361 has such a problem that, although the transporting carriage can directly access respective one of a plurality of racks which are the same in height to each other, the transporting carriage cannot directly access the racks which are different in height from each other.

It is therefore an object of the present invention to provide a suspended type transporting carriage, which can directly transfer a transported object to and from racks, which are lateral to the transporting carriage and are at least partly different in height from each other, can reduce the cost and can improve the reliability, as well as a transporting system using such a carriage.

The above object of the present invention can be achieved by a suspended type transporting carriage comprising: a gripping mechanism for gripping a transported object; a hoisting mechanism for hoisting said gripping mechanism; and a traveling mechanism, on which said hoisting mechanism is mounted in a suspended condition, for traveling on a rail installed on or near a ceiling, said gripping mechanism comprising (i) an elongating and contracting device capable of horizontally elongating and contracting and (ii) a gripping device disposed at a tip portion of said elongating and contracting device for selectively gripping the transported object.

According to the suspended type transporting carriage of the present invention, in operation, in order to transfer the transported object such as a FOUP or the like with respect to one rack plate of one rack device, the transporting carriage travels to and stops at a position corresponding to this one rack device by the traveling mechanism. Then, the gripping mechanism is moved down by the hoisting mechanism. Then, the elongating and contracting device, such as a sliding plate, is horizontally sent out while the gripping device at the tip portion grips or can grip the transported object. Accordingly, it is possible to transfer (i.e., put or pick up) the transported object with respect to a position, which is laterally away from the right beneath of the transporting carriage.

In one aspect of the suspended type transporting carriage of the present invention, said gripping mechanism further comprises a main body, which is hoisted by said hoisting mechanism, and said elongating and contracting device is capable of horizontally elongating and contracting with respect to said main body.

According to this aspect, the gripping device can be certainly elongated toward the rack device from the main body, and certainly contracted away from the rack device to the main body, by virtue of the elongating and contracting device.

In another aspect of the suspended type transporting carriage of the present invention, the suspended type transporting carriage further comprises an attitude keeping device, which detachably fixes one portion of said gripping mechanism and one portion of rack plates of a rack device to each other, for keeping or stabilizing an attitude of said gripping mechanism with respect to said rack device.

According to this aspect, upon transferring the transported object, the attitude, posture or balance of the gripping mechanism can be kept or stabilized by virtue of the attitude keeping device, as it fixes the gripping mechanism and the rack device to each other.

The above object of the present invention can be achieved by a transporting system comprising (I) the above describe suspended type transporting carriage of the present invention and (II) a rack device having a plurality of rack plates, which are vertically arranged at different heights from each other, for temporarily storing the transported object.

According to the transporting system of the present invention, since it is provided with the above describe suspended type transporting carriage of the present invention, it is possible to transfer the transported object with respect to a position, which is laterally away from the right beneath of the transporting carriage. Further, since it is not necessary to equip a sliding mechanism to each rack plates, the total number of parts or components constituting the elongating and contracting device (or the sliding mechanism or the like) can be certainly diminished. Also, it is not necessary to equip a driving mechanism to each rack plates. Thus, the increase of the cost can be avoided. In addition, it is possible to avoid such a case that a failure of just one of a plurality of sliding mechanism leads to the total failure or the total adverse affect of the transporting system, since the sliding mechanism does not exist in each of the rack plates.

In this manner, according to the present invention, since it is not necessary to equip the elongating and contracting device (or the sliding plate or the like) to each of the rack plates but since it is enough to equip the elongating and contracting device to the side of the transporting carriage, it is possible to reduce the cost and increase the reliability.

In one aspect of the transporting system of the present invention, the transporting system further comprises an attitude keeping device, which detachably fixes one portion of said gripping mechanism and one portion of said rack plates to each other, for keeping or stabilizing an attitude of said gripping mechanism with respect to said rack device.

According to this aspect, even in such a case that the elongating and contracting device elongates by more distance to a rack plate, which is relatively distant from the position right beneath the transporting carriage, so as to transfer the transported object with respect to this rack plate, or in such a case that a heavier transported object is gripped while the elongating and contracting device elongates, it is still possible to keep the attitude of the gripping mechanism and thereby transfer the transported object in stable.

In the above mentioned aspect comprising the attitude keeping device, said attitude keeping device may comprise a rod portion on said gripping mechanism and a latch portion on said rack plates, so that said rod portion can be engaged with said latch portion.

By constructing in this manner, when the elongating and contracting device elongates, the rod portion is engaged with the latch portion. The rod portion may enter upside or downside of the rack plate. Thus, it is possible to easily fix the gripping mechanism with respect to the rack device, and thereby keep the attitude of the gripping mechanism. Also, by equipping the latch portion to respective one of the rack plates, it is possible to fix the gripping mechanism upon transferring the transported object with respect to any one of the rack plates.

In the above mentioned aspect comprising the attitude keeping device, in case that the transported object is transferred between said gripping mechanism and one plate of said rack plates, said rod portion may be engaged with said latch portion of another plate of said rack plates, said another plate being right above said one plate.

By constructing in this manner, the rod portion is engaged with the latch portion of another rack plate right above one rack plate with respect to which the transported object is transferred. Thus, the forward space of the one rack plate, with respect to which the transported object is transferred, is wide open. Namely, it is possible to avoid the movement of the elongating and contracting device from being interfered by the attitude keeping device. Accordingly, it is possible to easily perform the transferring operation while surely keeping the attitude.

In the above mentioned aspect comprising the attitude keeping device, said rod portion may be capable of elongating or rotating with respect to said gripping mechanism toward said latch portion, so that a tip of said rod portion can be engaged with the latch portion after said rod portion is elongated or rotated in a predetermined direction.

By constructing in this manner, by horizontally elongating or semi-circularly rotating the rod portion, it is possible to easily and surely engage the rod portion with the latch portion.

As describe above in detail, according to the suspended type transporting carriage and the transporting system of the present invention, it is not necessary to equip the sliding mechanism to each of the rack plates. It is possible to access to a desirable rack plate and perform the transferring operation thereat. Accordingly, it is possible to reduce the total cost as for the whole system while improving the reliability of the whole system.

The nature, utility, and further features of this invention will be more clearly apparent from the following detailed description with respect to preferred embodiments of the invention when read in conjunction with the accompanying drawings briefly described below.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the accompanying drawings, embodiments of the present invention will be now explained.

At first, an overall structure of a transporting system as an embodiment of the present invention is explained with referring toFIG. 1.FIG. 1shows a semiconductor manufacturing facility, in which the transporting system having a transporting carriage as the embodiment is used.

InFIG. 1, the transporting system is used for transporting the transported object by the transporting carriage in-between one process or between a plurality of processes, so that various processes are sequentially applied to the transported object, as in a semiconductor manufacturing factory, and a final product is completed. The semiconductor manufacturing facility is constructed such that a plurality of processing portions18are arranged. Each of the processing portions18is provided with: one or plurality of rack devices13; and a plurality of processing devices15whose processes are different from each other. The rack device13and the processing devices15in respective one of the processing portions18are connected to an inter-process track10through an intra-process track11and a diverged track12.

As shown inFIG. 1, the transporting system has such a structure that a plurality of transporting carriages16travel on traveling paths comprising the inter-process track10, the intra-process tracks11and the diverged tracks12. The traveling paths are disposed above (i.e., on the side of the ceiling of) the semiconductor manufacturing factory. A FOUP (Front Opening Unified Pod)17is hoisted to be suspended by the transporting carriage16and is transported. Here, the FOUP17is a container for contain a plurality of semiconductor substrates. The FOUP17has a substantially rectangular parallelepiped shape. On a center of an upper surface of the FOUP17, a flange27is equipped so as to be gripped and transported. The semiconductor substrates are contained in the FOUP17and are transported, so that various processes such as thin film formation by CVD, ion injection, photo-lithography, etching, inspection and so forth are applied by various processing devices. A stocker (or stacker)14is disposed so as to be connected to the inter-process track10, and plays a role of storing the FOUP17during a waiting time duration for each process, as a storing device for storing a plurality of FOUPs17.

Next, the transporting carriage16and the rack device13in one embodiment will be explained with referring toFIG. 2withFIG. 1.FIG. 2shows the transporting carriage16and the rack device13in such a condition that the transporting carriage16transfers the FOUP17with respect to a desired position of the rack device13in one embodiment.

As shown inFIG. 2, the transporting carriage16is adapted to travel on a rail20of the traveling path, by a traveling mechanism60having a linear motor for example (not-illustrated) and moves to a position of destination. The transporting carriage16is provided with a hoisting belt21and a gripping mechanism22.

One transporting carriage16has four hoisting belts21, which are wound around reels housed in the transporting carriage16. The gripping mechanism22is suspended by four hoisting belts21at the tip portions thereof. The gripping mechanism22is moved up and down through the hoisting belts21by the forward and reverse rotations of the reels by virtue of the driving mechanism such as a motor etc., which is not illustrated. Each of the hoisting belts21has such a length that the gripping mechanism22can move the FOUP17in the up and down direction, until the height of a fixed rack plate25, which is positioned at the lowest, among a plurality of fixed rack plates25of the rack device13.

The gripping mechanism22is provided with a sliding mechanism23and a gripper24. The sliding mechanism23, which constitutes one example of “the elongating and contracting device” of the present invention, is adapted to be elongated and contracted in a horizontal direction by a ball screw driving mechanism, which is not illustrated, with respect to a main body22mof the gripping mechanism22. The gripper24, which is adapted to grip the flange27of the FOUP17, is attached to a bottom portion of the sliding mechanism23. The gripper24has an open and close capability of gripping the flange27of the FOUP17and is constructed to grip the flange27when the sliding mechanism23is elongated to be at a position right above the FOUP17.

As shown inFIG. 2, the rack device13is provided with a brace member or members26and a plurality of fixed rack plates25arranged in the vertical direction with intervals. The processes by the processing devices15are different in their contents from each other, so that their processing time durations are also different from each other. Accordingly, an indefinite waiting time duration is generated until the next process is applied. Although the stocker14may store the FOUP14during the waiting time duration, the stocker14has such a drawback that the stocker14cannot speedily deal, since the stocker14is distant from the processing device15and it takes a certain time period for the stocker14to load and unload the FOUP17. Therefore, the rack device13is disposed at the vicinity of the processing device15as a simplified storing place for the FOUP17during the waiting time duration.

Here, the principle of carrying in (i.e., loading) and carrying out (i.e., unloading) the FOUP17with respect to the rack device13by the transporting carriage16is explained with referring toFIG. 2.

The carrying out operation of the FOUP17is as following. Namely, the transporting carriage16, which has traveled on the inter-process track11and has stopped at the position opposed to the rack device13, winds out the hoisting belt21by rotating the reel by virtue of the motor or the like. By this, the transporting carriage16moves the gripping mechanism22, which does not grip the FOUP17, down to the position at a predetermined height. After the gripping mechanism22is moved down to the target position of one of the fixed rack plates25, the sliding mechanism23is elongated or expanded, so that the sliding mechanism23is entered to the position right above one of the FOUPs17within the rack device13, where the flange27fthe FOUP17is gripped by the gripper24. After the FOUP17is gripped, the sliding mechanism23is contracted or shrunk. Successively, the hoisting belt21is wound up by rotating the reel, so that the FOUP17is moved up together with the gripping mechanism22. After that, the transporting carriage16travels on the inter-process track11toward a next transportation destination of the FOUP17.

In case that the transporting carriage16puts the FOUP17onto the rack device13, the putting (i.e., carrying in) operation of the FOUP17can be performed in the reverse order of the above described carrying out operation. Namely, the transporting carriage16, which is gripping the FOUP17by the gripper24and has traveled on the inter-process track11, stops at the position opposed to the rack device13, onto which the FOUP16is to be put. Next, the transporting carriage16winds out the hoisting belt21by rotating the reel by virtue of the motor or the like. By this, the transporting carriage16moves the gripping mechanism22, which is gripping the FOUP17, down to the position at the height of the fixed rack plate25, onto which the FOUP17is to be put. After that, the sliding mechanism23is elongated or expanded, so that the FOUP17is moved to the position right above the fixed rack plate25, where the FOUP17is put onto the rack device13by releasing the gripper24.

Next, the transporting carriage16and the rack device13in another embodiment will be explained with referring toFIG. 3withFIG. 1.FIG. 3shows the transporting carriage16and the rack device13in such a condition that the transporting carriage16transfers the FOUP17with respect to a desired position of the rack device13in another embodiment.

The above explanation is the principle of transferring (i.e., carrying-in and carrying-out) the FOUP17with respect to the rack device13. Upon transferring, there may be a case that the FOUP17is transferred to the rack device13, which is distant from the position right under the transporting carriage16, or a case that a heavier FOUP is transported to the rack device13. Namely, the transporting system in another embodiment is provided with the “attitude keeping device” as described below, in order to realize a stabilized transferring operation, even in such a case that the sliding mechanism23is elongated to a more distant position or such a case that a heavier FOUP is gripped when the sliding mechanism23is expanded.

InFIG. 3, the transporting system in the present embodiment is provided with the attitude (i.e., posture or balance) keeping device, which is different from the transporting system of the embodiment shown inFIG. 2. The attitude keeping device is provided with: a rod30disposed to the gripping mechanism22; and a latch portion31disposed to the fixed rack plate25. The rod30is disposed to the upper portion of the gripping mechanism22, so that the rod30is engaged with the latch portion31of the fixed rack plate25, which is disposed just above the fixed rack plate25of the transferring target, when the sliding mechanism23is elongated. Thus, the attitude keeping is enabled by fixing the transporting carriage16to the rack device13.

Hereinbelow, the attitude keeping operation of the gripping mechanism22, which is gripping the FOUP17, by virtue of the attitude keeping device is explained with referring toFIG. 3.

InFIG. 3, the transporting carriage16stops at the position opposed to the rack device13, moves the gripping mechanism22, which is gripping the FOUP17, down to the position at the position A of the fixed rack plate25, onto which the FOUP17is to be put. After that, the sliding mechanism23is elongated, and the rod30is sent out toward the rack device13. At this time, the rod30is engaged with the latch portion31of the fixed rack plate25at a position B, which is just above the fixed rack plate25at the position A of the transferring target. By this, the gripping mechanism22is stabilized (i.e., the attitude, posture or balance of the gripping mechanism22is kept), and it is possible to transfer the FOUP17in stable, even in such a case that the sliding mechanism23is elongated to a more distant position or such a case that a heavier FOUP17is gripped when the sliding mechanism23is expanded.

Next, various examples of the “attitude keeping device” having the rod and the latch portion of the present embodiment will be explained with referring toFIG. 4AtoFIG. 8B. Each ofFIGS. 4A,5A,6A,7A and8A is a perspective view of the attitude keeping device while each ofFIGS. 4B,5B,6B,7B and8B is a corresponding side view, respectively.

InFIGS. 4A and 4B, the attitude keeping device is provided with a set of protruding rods40and a set of rod bearings44. Each of the protruding rods40has a rod member. Each of the rod bearings44has a rod member in each of which a concave portion48is vertically formed at the edge portion of the fixed rack plate25on the side where the gripping mechanism22is entered. When the sliding mechanism23is elongated, each of the protruding rods30horizontally protrudes from a position indicated by a chain double-dashed line to a position indicated by a solid line inFIGS. 4A and 4B. As the protruding rods40are engaged with the rod bearings44, the gripping mechanism22is stabilized or fixed to the rack device13.

InFIGS. 5A and 5B, the attitude keeping device is provided with a set of rotational rods41and a set of rod bearings45to latch or lock the rotational rods41. Each of the rod bearings45has a rod member in each of which a concave portion49is vertically formed at the edge portion of the fixed rack plate25on the side where the gripping mechanism22is entered, as in the case of the rod bearings44shown inFIGS. 4A and 4B. On the other hand, each of the rotational rods41has a rod member (as in the case of the protruding rods40shown inFIGS. 4A and 4B), which is rotatably fixed on the gripping mechanism22at one end thereof and is to caracole in a semicircular shape. This is contrast to the protruding rods40which is to horizontally protrude. Namely, each of the rotational rods41draws a semicircle with the end, which is rotatably fixed to the gripping mechanism22, as the fulcrum point, to move from a position indicated by a chain double-dashed line to a position indicated by a solid line inFIGS. 5A and 5B. As the rotational rods41are engaged with the rod bearings45, the gripping mechanism22is stabilized or fixed to the rack device13.

InFIGS. 6A and 6B, the attitude keeping device is provided with a set of inserting rods42and a set of tube rod bearings46. Each of the inserting rods42has a rod member in a circular cylinder shaped. Each of the tube rod bearings46has a tube member in which a hollow space is formed. As the slide mechanism23is elongated or expanded, each of the inserting rods42moves from a position indicated by a chain double-dashed line to a position indicated by a solid line inFIGS. 6A and 6B. As the tip portions of the inserting rods42are respectively inserted into the tube rod bearings46, the gripping mechanism22is stabilized or fixed to the rack device13.

InFIGS. 7A and 7B, the attitude keeping device is provided with a set of absorbing or sucking rods43and a set of rod bearings47. Each of the absorbing or sucking rods43has an electric magneto, sucker or the like at the tip portion thereof and each of the rod bearings47has a magnetic body, a smooth surface or the like at the edge or concave surface thereof, or vice versa. Accordingly, each of the absorbing or sucking rods is latched or locked to the tip portion of each of the absorbing or sucking rod43.

InFIGS. 8A and 8B, in case that the fixed rack plate25is thick enough, a pair of inserting portions52may comprise a pair of holes52, which are formed at the surface, where the gripping mechanism22is entered, i.e., at the surface facing to a pair of protruding rods51, of the fixed rack plate25.

Next, comparison examples will be explained with referring toFIG. 9andFIG. 10, in order to exhibit the advantageous features of the present embodiments.FIG. 9andFIG. 10show comparison examples, respectively.

InFIG. 9, a rack device13cof the comparison example has a sliding rack plate50, which is slidable on the fixed rack plate25. In this case, the transferring operations to and from the rack device13ccan be easily performed by linking the movement of the hoisting belt21and the movement of the sliding rack plate50.

However, in this comparison example ofFIG. 9, since the driving mechanism including gears, a driving motor and so forth is required to each of the sliding rack plates50, the cost of the rack device13cbecomes essentially quite high. Further, a failure in just one sliding rack plate50may cause the total failure of the rack device13c, which certainly degrades the reliability of the rack device13c. In contrast, the rack device13of the present embodiment has the great advantage of high reliability with relatively low cost since just one sliding mechanism23is required to perform the transferring operations and since the structure of the rack device13is relatively simple.

InFIG. 10, a rack buffer13dof the comparison example is quite simple. In this case, the transporting carriage travels on the rail20by a traveling mechanism60. A hoisting mechanism63of the transporting carriage is slid by a sliding mechanism62and is stopped and positioned by a positioning mechanism61. The hoisting mechanism63is slid between the position right underneath the rail20and the lateral position of the rail20, so that the gripping mechanism22can directly access the port of the rack buffer13d.

However, in this comparison example ofFIG. 10, the gripping mechanism22cannot directly access the racks which are different in height from each other. In contrast, the rack device13of the present embodiment has the great advantage that the gripping mechanism22can directly access one of the ports of the rack device13, which are positioned at various heights.

The entire disclosure of Japanese Patent Application No. 2007-60512 filed on Mar. 9, 2007 including the specification, claims, drawings and summary is incorporated herein by reference in its entirety.