Abstract:
An assembly to facilitate the transport of semiconductor wafers comprises rigid first and second end plates, and a plurality of interconnected flexible pockets provided between these first and second end plates. Each of the pockets is configured to store a semiconductor wafer therein. 
     A method of facilitating the transport of semiconductor wafers comprises inserting semiconductor wafers into pockets of a wafer transport assembly, the assembly having rigid first and second end plates, and a plurality of interconnected flexible pockets attached therebetween. The method further comprises collapsing the pockets down onto the semiconductor wafers by moving the first end plate toward the second end plate. 
     A method of fabricating an assembly to facilitate the transport of semiconductor wafers comprises providing a plurality of interconnected flexible pockets between rigid first and second end plates, each of these pockets being configured to store a semiconductor wafer therein.

Description:
BRIEF DESCRIPTION OF THE INVENTION 
   This invention relates generally to semiconductor wafer fabrication. More specifically, this invention relates to an apparatus and method for facilitating the transport of semiconductor wafers. 
   BACKGROUND OF THE INVENTION 
   Cassette carriers are often used to transport finished semiconductor wafers prior to dicing. However, these carriers suffer from certain drawbacks. Current cassette carriers maintain excessive space between wafers, taking up too much volume in transport and resulting in unnecessary expense. Current carriers also expose wafers to excessive risk of shock due to rough handling, and are relatively expensive. 
   Therefore, it would be highly desirable to design a more compact cassette carrier that requires less volume in transport. It would also be desirable to design this carrier to better cushion wafers from shock during transport, and to be manufactured more cheaply. 
   SUMMARY OF THE INVENTION 
   An assembly to facilitate the transport of semiconductor wafers comprises rigid first and second end plates, and a plurality of interconnected flexible pockets provided between these first and second end plates. Each of the pockets is configured to store a semiconductor wafer therein. 
   A method of facilitating the transport of semiconductor wafers comprises inserting semiconductor wafers into pockets of a wafer transport assembly, the assembly having rigid first and second end plates, and a plurality of interconnected flexible pockets attached therebetween. The method further comprises collapsing the pockets down onto the semiconductor wafers by moving the first end plate toward the second end plate. 
   A method of fabricating an assembly to facilitate the transport of semiconductor wafers comprises providing a plurality of interconnected flexible pockets between rigid first and second end plates, each of these pockets being configured to store a semiconductor wafer therein. 
   The various assemblies of the invention allow for more compact transport of semiconductor wafers. These assemblies can also be manufactured more cheaply than current cassette carriers, and can better cushion wafers from shock during transport. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which: 
       FIG. 1  illustrates an isometric view of a wafer transport assembly constructed in accordance with an embodiment of the invention. 
       FIG. 2  illustrates a collapsed state of a wafer transport assembly constructed in accordance with an embodiment of the invention 
       FIG. 3  illustrates a front view of a wafer transport assembly constructed in accordance with an embodiment of the invention. 
   

   Like reference numerals refer to corresponding parts throughout the drawings. 
   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  illustrates a wafer transport assembly  10  constructed in accordance with an embodiment of the invention. The wafer transport assembly  10  includes rigid first and second end plates  12 ,  14  connected by flexible walls  16 ,  18 . The flexible walls  16 ,  18  are creased to provide a series of folds  20 ,  22 . In a first embodiment of the invention, removable support jigs  24  are provided with holes  26  and teeth  28 . When the support jigs  24  are placed between the end plates  12 ,  14 , the end plates  12 ,  14  are maintained a predetermined distance H 1  from each other, the distance H 1  corresponding to the height of the jigs  24 . Simultaneously, the teeth  28  insert themselves within each fold  20 ,  22  so as to space each fold  20 ,  22  out. This spacing creates a number of interconnected flexible pockets  30 , each capable of holding a semiconductor wafer  32  therein. 
   In operation, the support jigs  24  are placed between the rigid end plates  12 ,  14 . In doing so, teeth  28  are inserted between the folds  20 ,  22 . This stretches out the flexible walls  16 ,  18 , and opens the pockets  30  to a predetermined size, namely the spacing H 2  between teeth  28 . A semiconductor wafer  32  can then be inserted into the pockets  30 . The support jigs  24  are sized to facilitate insertion of the wafers  32 . For instance, the height H 1  of the support jigs  24 , as well as the spacing H 2  between teeth  28 , can be made identical to corresponding dimensions in other wafer containers used in the fabrication process, to facilitate easy loading from one container or holding device to the assembly  10  of the invention. In addition, holes  26  can be spaced to mate with alignment pins located on other containers, thus facilitating easier attachment to these containers, and easier wafer transfer. Two transport assemblies  10  can thus be connected face to face to facilitate wafer transfer between them, in much the same way as current cassette carriers. 
   Once wafers  32  are loaded into the pockets  30 , the support jigs  24  can be removed from between the end plates  12 ,  14 , allowing the end plates  12 ,  14  to collapse down onto the wafers  32 . In this collapsed state, the end plates  12 ,  14  assume a compressed position in which they compress the flexible walls  16 ,  18 , and thus the pockets  30 , down onto the wafers  32 . In this manner, the wafers  32  are affixed within the pockets  30 . 
   The rear of assembly  10  can be left open if there is no risk of wafers sliding out of the pockets  30 . Alternatively, additional flexible material may be placed along the rear of assembly  10  to further minimize this risk. For instance, a strip of flexible material can be attached to the rear of end plates  12 ,  14 , or another flexible wall can be provided. In the latter case, a corresponding additional support jig  24  may also be required. 
   The invention discloses the use of any conventional mechanism of feature to prevent the jigs  24  from prematurely sliding out from between the end plates  12 ,  14 . For instance, the support jigs  24  can be fabricated of a ferrous metal, and magnets can be attached to the inside edges of end plates  12 ,  14 . Additionally, an adhesive can be used to detachably bond the support jigs  24  to the end plates  12 ,  14 , or the edges of end plates  12 ,  14  and jigs  24  can be designed with snap-fit joints. 
   The compressed position of the assembly  10  offers advantages over current cassette carriers. First, one of skill in the art can observe that fabricating the flexible walls  16 ,  18  of a sufficiently thin material allows a collapsed state in which the pockets  30  hold the wafers  32  in much closer proximity to each other than do current cassette carriers. This allows for more compact storage of wafers  32 . Second, because the wafers  32  are held in place by a flexible material (i.e., the material of the flexible walls  16 ,  18 ), and because the rigid end plates  12 ,  14  protect the wafers  32  from impact, they are less susceptible to shock than wafers stored in a conventional cassette carrier. 
   Finally, the assembly  10  can be manufactured of materials that are both inexpensive and compatible with contemporary wafer fabrication environments, allowing the assemblies  10  to be made more cheaply than current cassette carriers. For example, the end plates  12 ,  14  can be made of any rigid cleanroom-compatible material that also serves to absorb the energy of an impact, such as stainless steel or various inexpensive plastics. Similarly, the flexible walls  16 ,  18  can be made of inexpensive materials that are conducive to passivated semiconductor wafers (e.g., electrically conductive materials that can act to dissipate static electricity, or simple clean room compatible materials), such as carbon paper. Note that the specific materials mentioned here are shown by way of example and are not meant as limiting. Those of skill in the art will realize that the assembly  10  includes the use of any materials that are compatible with wafer fabrication environments. 
     FIG. 2  illustrates a collapsed state of a wafer transport assembly  10  constructed in accordance with an embodiment of the invention. In this embodiment, a clasping mechanism  100  is attached to the end plates  12 ,  14 . When the support jigs  24  are removed and the assembly  10  enters its collapsed state, the wafers  32  are affixed within the pockets  30 . The clasping mechanism  100  is then engaged to maintain the end plates  12 ,  14  in this compressed position, thus securing the wafers  32  within the pockets  30  for transport. One of skill in the art can observe that the collapsed state of assembly  10  acts to store wafers  32  much more compactly than current cassette carriers. Additionally, this collapsed state affixes the wafers  32  within flexible walls  16 ,  18  that absorb shock and impact more effectively than rigid cassette carriers. 
   The invention includes the use of any conventional clasp, including buttons, adhesive strips, and snaps, as the clasping mechanism  100 . In addition, the clasping mechanism can be permanently affixed to the end plates  12 ,  14 , or separately attachable. As an example of the latter, the clasping mechanism  100  can be an elastic strip that stretches around the end plates  12 ,  14 , or a C-clamp. 
     FIG. 3  illustrates a front view of a wafer transport assembly  10  constructed in accordance with an embodiment of the invention. In some instances, it is desirable to fully enclose wafers during transport, so as to ensure that individual wafers do not contact each other and cause the destruction of their various integrated circuits. In order to fully enclose wafers, the assembly  10  of this embodiment of the invention includes protective material  200  connecting the folds  20 ,  22 . When wafers  32  are inserted into the pockets  30 , the folds  20 ,  22  and protective material  200  completely surround the wafers  32 . One of skill in the art will observe that, when the support jigs  24  are removed and the assembly  10  enters its collapsed state, the wafers  32  are fully enclosed within the pockets  30 , and are thus prevented from contacting each other during handling or transport. 
   It should be noted that the invention is not limited to embodiments in which the support jigs  24  are removable from between the end plates  12 ,  14 . Rather, the invention includes embodiments in which the support jigs  24  are made from compressible materials. In some such embodiments, the support jigs  24  need not be removed prior to collapsing the end plates  12 ,  14 . Instead, the support jigs  24  can be designed to maintain the end plates  12 ,  14  at a predetermined distance from each other when uncompressed, but also to collapse down along with the end plates  12 ,  14  when pressure is applied. In this manner, the assembly  10  can comprise a single, integrated assembly that has no removable parts. 
   Similarly, it should also be noted that the invention includes the simultaneous use of various aspects of different embodiments. For instance, the assembly  10  can be designed as a single, integrated assembly with compressible support jigs  24  and a clasping mechanism  100 . In this manner, once the end plates  12 ,  14  are compressed to affix wafers  32  within the pockets  30 , the clasping mechanism  100  can be engaged to maintain this compressed position for easier wafer transport. 
   The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the invention. Thus, the foregoing descriptions of specific embodiments of the present invention are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, obviously many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.