Wafer cassette

Abstract

A front opening wafer container including an enclosure portion and a door. A wafer support system is provided including a pair of spaced apart cantilever wafer shelves, each wafer shelf including a pair of opposing inclined ramp portions. The ramp portions are cooperatively positioned and configured so that when the wafer is received on the shelves, the wafer is supported on the ramps at a lower peripheral corner of the wafer, all other portions of the wafer being free from contact with the wafer support system. Each wafer shelf may have a generally concave upper surface and the incline of the ramps is continuous with the concave upper surfaces of the wafer shelves.

1 . A wafer container comprising:
 a plurality of wafers;   an enclosure portion including a top, a bottom, opposing sides, a back and an open front defined by a door frame;   a door selectively receivable in the door frame to sealingly close the open front; and   a wafer support system in the enclosure for receiving and supporting the wafer, the wafer support system including a pair of spaced apart cantilever wafer shelves, each wafer shelf including a pair of separated and opposing arcuate inclined ramp portions, one of the pair facing radially inwardly and forwardly, the other of the pair facing radially inwardly and rearwardly, the ramp portions cooperatively positioned and configured so that when the wafer is received on the shelves, the wafer is supported on the ramps at a lower peripheral corner of the wafer and partially down said ramps, all other portions of the wafer being free from contact with the wafer support system.   
     
     
         2 . The wafer container of  claim 1 , wherein the ramps are inclined at between one degree and nine degrees with respect to the horizontal. 
     
     
         3 . The wafer container of  claim 1 , wherein the ramps are inclined at between three degree and seven degrees with respect to the horizontal. 
     
     
         4 . The wafer container of  claim 1 , wherein the ramps are inclined at about five degrees with respect to the horizontal. 
     
     
         5 . The wafer container of  claim 1 , wherein each wafer shelf has a generally concave upper surface. 
     
     
         6 . The wafer container of  claim 5 , wherein the plurality of wafers each have a pair of lateral edge portions, each intermediate one of the pairs of opposing arcuate inclined ramp portions, said lateral edge portions not being supported by or in vertical alignment with the respective opposing arcuate inclined ramp portions. 
     
     
         7 . The wafer container of  claim 1 , wherein the wafer support system comprises a pair of wafer support structures, and wherein each wafer support structure includes a column with one of the pair of wafer shelves extending therefrom. 
     
     
         8 . The wafer container of  claim 7 , wherein each of the wafer support structures is secured in the enclosure portion with a plurality of fasteners. 
     
     
         9 . The wafer container of  claim 7 , wherein the wafer support structures are integrally molded with the enclosure portion using an overmolding process. 
     
     
         10 . The wafer container of  claim 7 , wherein the column and wafer shelves are integrally formed in one piece. 
     
     
         11 . A wafer comprising:
 a plurality of wafers;   an enclosure portion including a top, a bottom, opposing sides, a back and an open front defined by a door frame;   a door selectively receivable in the door frame to sealingly close the open front; and   a wafer support system in the enclosure for receiving and supporting the plurality of wafers in a horizontally oriented, spaced apart, axially aligned arrangement, the wafer support system including a pair of spaced apart opposing wafer support structures positioned and attached to the enclosure portion at the back of the enclosure portion, each wafer support structure including a column with a plurality of spaced apart cantilever wafer shelves extending therefrom toward the open front, each of the wafer shelves of a first one of the wafer support structures horizontally registered with one of the wafer shelves of the other wafer support structure to define a plurality of horizontally oriented slots, each for receiving one of the plurality of wafers, each wafer shelf including a pair of opposing and separated inclined ramp portions for contacting the wafer, the ramp portions cooperatively positioned and configured so that when the wafer is received in the slot, the wafer is supported on the ramps at a lower peripheral corner of the wafer, all other portions of the wafer being free from contact with the wafer support system.   
     
     
         12 . The wafer container of  claim 11 , wherein the ramps are inclined at between one degree and nine degrees with respect to the horizontal. 
     
     
         13 . The wafer container of  claim 11 , wherein the ramps are inclined at between three degree and seven degrees with respect to the horizontal. 
     
     
         14 . The wafer container of  claim 11 , wherein the ramps are inclined at about five degrees with respect to the horizontal. 
     
     
         15 . The wafer container of  claim 11 , wherein each wafer shelf has a generally concave upper surface. 
     
     
         16 . The wafer container of  claim 15 , wherein the incline of the ramps is continuous with the concave upper surfaces of the wafer shelves. 
     
     
         17 . A wafer container comprising:
 at least one wafer;   an enclosure portion including a top, a bottom, opposing sides, a back and an open front defined by a door frame;   a door selectively receivable in the door frame to sealingly close the open front; and   means for supporting the wafer in the enclosure, said means attached at the back of the enclosure portion and cantilevered toward the open front, said means supporting the wafer at a plurality of spaced apart locations along lower peripheral corner of the wafer, all other portions of the wafer being free from contact with the container.   
     
     
         18 . The wafer container of  claim 17 , wherein said means for supporting the wafer in the enclosure includes a plurality of wafer support structures spaced inwardly from the most lateral points of the wafer. 
     
     
         19 . The wafer container of  claim 18 , wherein each wafer support structure includes a column with a plurality of spaced apart cantilever wafer shelves extending therefrom, each wafer shelf including a pair of opposing inclined ramp portions for contacting the wafer. 
     
     
         20 . The wafer container of  claim 19 , wherein the ramps are inclined at about five degrees with respect to the horizontal.