Abstract:
A cassette stocker and method of forming the same. The cassette stocker comprises a housing, at least one operation device, and a transferring device. The housing comprises a plurality of openings. The operation device is disposed corresponding to the openings and storing a cassette. The transferring device is disposed in the housing, retrieving and transferring the cassette stored in the operation device via the openings.

Description:
BACKGROUND  
       [0001]     The present invention relates to a cassette stocker and method of forming the same, and more particularly to a cassette stocker with modular operation devices.  
         [0002]     A cassette stocker is a stocker, for storing and transferring cassettes.  FIG. 1A  shows a conventional cassette stocker, which comprises a huge housing  510  and a plurality of operation devices  520  such as substrate exchangers, for storing the cassettes  560 . A transferring device, such as a crane  540  on a rail  530 , is provided in the housing  510  to retrieve and transfer a cassette  560  in the operation devices  520 . As shown in  FIG. 1B  and  FIG. 1C , the crane  540  has a rotating platform to retrieve the cassette  560  from one operation device  520 , and transfer the cassette  560  to other operation devices  520 . Further, the housing  510  comprises an air cleaner  550 , such as a fan filter unit (FFU), to filter air in the housing  510  and reduce pollution therein.  
         [0003]     In the conventional cassette stocker, the housing  510  encloses the operation devices  520  and the transferring device. The operation devices  520 , however, are fixed in the housing  510 , and if one operation device  520  is out of order, operation in the cassette stocker is interrupted to disassemble and repair the operation device  520 , which reduces retrieval and transferring efficiency.  
         [0004]     Further, the operation devices  520  are fixed in the housing  510  and share a single air cleaner  550  on the housing  510 . Thus, the operation devices  520  are operated under the same environment. If pollution (such as dust or particles) occurs in one operation device  520 , the other operation devices  520  would be affected by retrieving and transferring of the crane  540 , and it is hard to distinguish where the pollution from.  
       SUMMARY  
       [0005]     Accordingly, embodiments of the present invention disclose a cassette stocker. The cassette stocker comprises a housing, at least one-operation device, and a transferring device. The housing comprises a plurality of openings. The operation device is disposed corresponding to the openings and storing a cassette. The transferring device is disposed in the housing, retrieving and transferring the cassette stored in the operation device via the openings.  
         [0006]     Further, another embodiment discloses a method of forming a cassette stocker. A housing with a plurality of openings is provided. A operation device detachably connected to the housing via the openings for storing the cassette is provided. A transferring device movably disposed between the openings is provided in the housing, retrieving and transferring the cassette stored in the operation device.  
         [0007]     In the method mentioned above, the operation device is disposed outside of or movably in the housing. The cassette stocker further comprises a plurality of blocking plates disposed corresponding to the openings and movably blocking the openings and a moving device moving the operation device in the housing.  
         [0008]     The transferring device comprises a rail and a crane movably disposed on the rail, moving between the openings along the rail.  
         [0009]     Additionally, the operation device comprises a first air cleaner to filter air in the cassette. The housing comprises a second air cleaner to filter air in the housing. The first air cleaner and the second air cleaner can be a fan filter unit (FFU). As well, the opening are connected to a peripheral operation device which comprises a transmission device or a production device.  
         [0010]     A detailed description is given in the following embodiments with reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:  
         [0012]      FIG. 1A  is a schematic view of a conventional cassette stocker;  
         [0013]      FIG. 1B  is a schematic view of the conventional cassette stocker in  FIG. 1A  wherein the crane retrieves the cassette;  
         [0014]      FIG. 1C  is a schematic view of the conventional cassette stocker in  FIG. 1A  wherein the crane transfers the cassette;  
         [0015]      FIG. 2  is a schematic view of an embodiment of the cassette stocker of the present invention;  
         [0016]      FIG. 3A  is a schematic view of a further embodiment of the cassette stocker of the present invention; and  
         [0017]      FIG. 3B  is a schematic view of the cassette stocker in  FIG. 3A  wherein the operation device  20  is removed. 
     
    
     DETAILED DESCRIPTION  
       [0018]     Referencing to  FIG. 2 , an embodiment of the present invention of a cassette stocker is described hereinafter.  
         [0019]     In  FIG. 2 , the cassette stocker comprises a housing  10 , a plurality of operation devices  20  outside of the housing  10 , and a transferring device. The operation devices  20  can be pre-stored material exchangers, such as substrate exchangers in the present embodiment. The transferring device comprises a rail  30  and a crane  40  on the rail  30 .  
         [0020]     In the present embodiment, the operation devices  20  are disposed outside of the housing  10 , and the housing  10  has a plurality of openings  15  so that the crane  40  retrieves and transfers the cassette  60  through the openings  15 . The operation devices  20  are disposed corresponding to the openings  15  and storing the cassette  60 . The cassette  60  stores a plurality of pre-stored materials, such as substrates or flat panels (not illustrated). Each opening  15  without connection to the operation devices  20  has a blocking board  50  to keep the housing  10  in a sealed environment. The crane  40  is disposed movably on the rail  30  and can move between the openings  15  along the rail  30 , retrieving and transferring the cassette  60  stored in the operation devices  20 . The size of the openings  15  is substantially bigger/equal than the operation devices  20  or substantially bigger than the pre-stored materials.  
         [0021]     Further, each operation device  20  has an independent first air cleaner  25 , such as a fan filter unit (FFU), to filter air in the operation device  20 . The housing  10  also has a second air cleaner  70 , such as an FFU, to filter air in the housing  10 .  
         [0022]     In the present embodiment, only the crane  40  and the rail  30  are disposed in the housing  10 . The operation devices  20  are disposed outside of the housing  10 . When one operation device  20  is out of order, an opening  15  connected thereto is closed, and the operation device  20  is disassembled and repaired safely without affecting other operation device  20 . The operation in the cassette stocker is not interrupted. Thus, retrieval and transferring efficiency is not reduced due to any single operation device  20 .  
         [0023]     Further, each operation device  20  in the cassette stocker has its own independent first air cleaner  25 , and the housing  10  has a second air cleaner  70 , which ensures the operation devices  20  to operate under independent environments. If pollution (such as dust or particles) occurs in one operation device  20 , the other operation devices  20  would not be affected, and the polluted operation device  20  can be quarantined in time.  
         [0024]     A further embodiment of the present invention of the cassette stocker is described hereinafter with reference to  FIG. 3A  and  FIG. 3B .  
         [0025]     In  FIG. 3A  and  FIG. 3B , the cassette stocker comprises a housing  10 , a plurality of operation devices  20 , and a transferring device in the housing  10 . The housing  10  has a plurality of openings  15 . The transferring device comprises a rail  30  and a crane  40  on the rail  30 . The present embodiment in  FIG. 3A  and  FIG. 3B  differs from the embodiment in  FIG. 2  in some of the operation devices  20  are disposed in the housing  10 . Further, each opening  15  has a blocking plate  50  and a moving device  55 . The blocking plate  50  is disposed corresponding to the openings  15  and movably blocking the openings  15 . The moving device  55  moves the operation devices  20  in the housing  10 . Therefore, each operation devices  20  is moved between the outer and the inner sides of the housing  10  by the moving device  55  and the openings  15  corresponding thereto. The moving device  55 , such as a track, a plurality of wheels, balls, rolling needles, or other moving devices, is capable of moving the operation device  20  in the housing  10 .  
         [0026]     When the cassette stocker is in operation as shown in  FIG. 3A , the operation devices  20  are positioned in the housing  10 , and the corresponding openings  15  are blocked by the blocking boards  50  to keep the housing  10  in a sealed environment. Further, when one operation device  20  is out of order, the operation device  20  can be moved outward from the housing  10  through the opening  15  to perform maintenance, and the blocking board  15  blocks the opening  15  so that the remaining operation devices  20  in the cassette stocker can be in operation instead of interruption.  
         [0027]     It should be mentioned that the arrangement of the operation devices  20  can be determined according to the operation or space distribution in the cassette stocker. Specifically, a number of the operation devices  20  can be disposed outside of the housing  10  as the embodiment shown in  FIG. 2 , and a number of the operation devices  20  can be disposed in the housing as the embodiment shown in  FIG. 3A  and  FIG. 3B .  
         [0028]     In some embodiments, the cassette stocker can be operated with an additional transmission device or an production device. For example, the transmission device and/or the production device can be connected to the openings  15  of the housing  10 , so that the cassette  60  in the operation devices  20  can be transmitted between the cassette stocker and the transmission device and/or the production device. Generally, the transmission device can be a robot, a rolling plate or other transmission device, and the production device can be a developing device such as PVD or CVD device, an etching device, a categorizing device, or other devices utilized in production.  
         [0029]     While the invention has been described by way of example and in terms of preferred embodiments, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.