JPH0452622B2 - - Google Patents

Description

[Detailed description of the invention] (1) Technical field to which the invention pertains The present invention relates to a stocker for three-dimensionally storing a plurality of semiconductor wafer cassettes, particularly for semiconductor wafer cassettes having a feeding mechanism that is easy to drive and has high reliability. Regarding Stotzka.

(2) Description of the Prior Art Conventionally, semiconductor wafers have been stored by arranging the wafers in boxes called cassettes and storing the cassettes in clean storage shelves. This method has no problems when the number of cassettes to be stored is small, but as the number of cassettes increases, problems arise in terms of storage space and lot management of stored wafers. That is, the height of the storage shelf is limited due to the workability of storing the wafers in the storage shelf, and moreover, a large number of man-hours are required to manage the wafer cassettes stored in a large number of shelves in accordance with the lot numbers.

Therefore, a stocker was devised in which the shelves are arranged three-dimensionally and made rotatable, so that the bottom area is small and cassettes can be easily taken in and taken out. This stocker has two sprocket wheels 1 and 2 as shown in Figs.
A chain 5 is provided between the two sprocket wheels 3 and 4, a chain 6 is provided between the two sprocket wheels 3 and 4,
A plurality of shelves 7 to 18 are provided between the chains 5 and 6. According to this configuration, even if the position of each shelf is changed by rotating the sprocket wheel, each shelf is always kept in a horizontal state, but in reality, the wafer cassettes 19 are not placed on the shelves. When placed, the center of gravity of the shelf shifts and the shelf tilts, making it difficult to insert and remove cassettes. Furthermore, since cassettes cannot be inserted or removed from the side of the shelf board, it is difficult to apply this method to automated lines. In addition, chains always require slack when driving, which reduces shelf positioning accuracy, generates a lot of dust due to their structure, and requires oil and fat for lubrication, so they are not suitable for use in clean rooms. It's really inconvenient.

Furthermore, when the position of the shelf from which wafer cassettes are taken out is determined at one location, there is a limit to the number of shelves that can be moved to this location.

(3) Object of the Invention The object of the present invention is to provide a stocker for semiconductor wafer cassettes which is highly accurate and does not generate dust without the above-mentioned drawbacks of the prior art.

(4) Features of the Invention The present invention is characterized in that a stocker for semiconductor wafer cassettes has a shelf on which a plurality of semiconductor wafer cassettes are placed, and side plates provided at both ends of the shelf and fitted with the shelves. The semiconductor wafer cassette stocker is provided with a substantially vertically extending guide rail in the side plate and is provided with drive means for moving the shelf along the guide rail.

Another feature of the present invention is a stocker for semiconductor wafer cassettes, which includes a shelf on which a plurality of semiconductor wafer cassettes are placed, and side plates provided at both ends of the shelf, each of the side plates having a plurality of shelves arranged in a substantially vertical direction. first, second and third pairs of guide rails extending and parallel to each other are provided, and means for moving the shelf from said first pair of guide rails to said second or said third pair of guide rails are provided; It is located in the semiconductor wafer cassette stocker provided.

(5) Effects of the Invention According to the present invention, since each shelf is moved without using a chain, it is possible to realize a semiconductor wafer cassette stocker that does not generate dust and has high shelf positioning accuracy.

Furthermore, since a large number of shelves can be moved to the same location and wafer cassettes can be placed and taken out from this location, a large-capacity stocker can be easily realized.

(6) Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a side view of a stocker according to an embodiment of the present invention, and FIG. 4 is a front view. Thirty-two wafer cassettes 19 are placed on shelves 20-27, and each of these shelves 20-27 is held by shelves 24-26 by a first guide rail 28 and a second guide rail (not shown). has been done. Each shelf is maintained in its position by the guide fitting into the guide rail.
For example, the shelf 24 is held by guides 31, 32 that fit into a first guide rail, and guides 36, 37, similarly provided on the opposite side, that fit into a second guide rail. In this example, each guide is attached to supports 33 and 38. The vertical position of each shelf is maintained by vertical contact between the respective supports. The guide of the shelf 27 is pushed upward from the first and second guide rails, but at this time, the guide of the shelf 27 is pushed to the left in FIG. 3 by a stopper (not shown). After the third guide rail 29 and the fourth guide rail (not shown) move and fit into these guides, the stopper is released. Thereafter, the third guide rail 29 and the fourth guide rail move rightward in FIG. 3 (towards the rear of the stocker) and stop on the fifth guide rail 30 and the sixth guide rail (not shown). The fifth guide rail and the sixth guide rail hold the shelves 20 to 22, but after the shelf 23 moves toward the front of the stocker, the second guide rail holds the shelves 20 to 22.
The entire shelves 20 to 22 are lowered by one step by the shelf raising/lowering mechanism 35, and as a result, the shelf 19 is held at the top of the fifth and sixth guide rails. The shelf 23 that has moved toward the front of the stocker is pushed up by the first shelf raising and lowering mechanism 34, and as a result, each guide of the shelf 23 is fitted with the first and second guide rails, and the shelves 24 to 26 are moved upward. Each guide of the shelf 26 is pushed up and released from the first and second guide rails. By repeating these operations, each shelf can be moved freely.

Note that by reversing the operations of the first shelf raising/lowering mechanism 35, the second shelf raising/lowering mechanism 36, and the third and fourth guide rails, the moving direction of each shelf can be reversed.

According to the embodiment of the present invention, the position of each shelf can be set extremely accurately, and since no chain is used, less dust is generated from each linkage. Furthermore, since the drive mechanism is independent of the number of shelves, a stocker with any number of shelves can be easily realized by simply changing the lengths of the first, second, fifth, and sixth guide rails. Furthermore, since each shelf can be removed regardless of the drive mechanism, maintenance is also extremely easy.

FIG. 5 is a side view of a stocker according to another embodiment of the present invention. The front view is basically the same as FIG. 4, so it will be omitted.

In this embodiment, three shelves are used to increase the storage capacity by 1.5 times without changing the height of the stocker.
The 48 wafer cassettes 19 are placed on shelves 40-51, and each of these shelves 40-51 is placed on shelves 48-5.
1 is the eleventh (twelfth) guide rail 52 (the twelfth guide rail is not shown because it is on the back side of the figure).
The same applies to the 14th and 16th guide rails below) Shelf 44 ~
47 is the 13th (14th) guide rail 53, shelf 40 ~
43 is held by a fifteenth (sixteenth) guide rail 54. Each shelf is fitted with a guide rail by a guide provided on each shelf. For example, the shelf 51 has guides 57 and 58 (a similar guide is attached to the opposite side, not shown) attached to a support 56, and is thereby fitted with a guide rail. The support and movement of each shelf is the same as in the first embodiment, but the guide rail 55 that moves each shelf horizontally moves the 11th, 13th, and 15th guide rails according to a predetermined program. The difference is that the shelf can be moved to any position within the box and stopped at this position.

By performing such an operation, a large number of shelves can be mounted without increasing the height of the stocker.

Although this embodiment discloses a case in which there are three rows of shelves, it goes without saying that the shelves can be arranged in any row.

Furthermore, each pair of guide rails is made into a unit.
It is also possible to arbitrarily combine the number of rows of shelves.

[Brief explanation of the drawing]

1 and 2 are a side view and a front view, respectively, of a conventional stocker for semiconductor wafer cassettes, and FIG.
FIG. 4 is a side view of a stocker for semiconductor wafer cassettes according to a first embodiment of the present invention, FIG. 4 is a front view thereof, and FIG. 5 is a side view of a stocker for semiconductor wafer cassettes according to a second embodiment of the present invention. In the figure, 1 to 4... Sprocket wheel, 5, 6... Chain, 7 to 18... Shelf, 1
9...Wafer cassette, 20-27, 40-51
... Shelf, 28 ... First guide rail, 29 ...
Third guide rail, 30... Fifth guide rail, 31, 32, 36, 37, 57, 58... Guide, 33, 38, 56... Support, 34... First shelf raising and lowering mechanism, 35...Second shelf raising/lowering mechanism, 52...Eleventh guide rail, 53...No.
13 guide rail, 54...15th guide rail, 55...horizontal movement guide rail.

Claims (1)

[Claims] 1. A storage shelf for multiple cassettes capable of mounting multiple cassettes containing multiple wafers;
A guide means for vertically guiding the cassette storage shelf while keeping the cassette mounting surface horizontal by guiding at least two guides provided at each end of the cassette storage shelf; at least two other guide means arranged in parallel with the guide means, and two transporters for horizontally transporting the cassette storage shelf between the upper and lower ends of the plurality of guide means, respectively. and elevating means provided corresponding to the plurality of guide means and for lifting and lowering the plurality of cassette storage shelves guided by the plurality of guide means. .