Cushioning for packing cassette cases

Abstract

[Problem] To provide a cushioning material that protects semiconductor wafers from an external impact when a cassette case is placed and packed in a cardboard box. [Resolution Means] When a cassette case for wafers is placed in a cardboard box, a cushioning member is provided in a space with an internal wall of the cardboard box. The cushioning member includes an upper molded member and a lower molded member, which sandwich the cassette case from above and under to suspend the cassette case. The upper molded member and lower molded member have rectangular frame bodies that surround and fix a lid and a bottom surface of the cassette case respectively. A plurality of impact absorbing blocks that protrude toward the internal wall surface of the cardboard box, are disposed within a diameter width of the semiconductor wafers W in the cassette case when the main surface of the wafers W are viewed from front.

1 . A cushioning body for packing a cassette case provided between the cassette case and a box, when the cassette case having a box shape is placed and packed in the box having a rectangular parallelepiped shape, the cassette case being loaded therein with a plurality of semiconductor wafers having a main surface thereof standing substantially vertically, the cushioning body for packing the cassette case comprising: 
 a lower molded member that has a substantially rectangular frame body, fits to a bottom portion of the cassette case, contacts an internal bottom wall of the box, and supports the cassette case while having a space between an external wall of the cassette case and an internal wall of the box; and    an upper molded member that has a substantially rectangular frame body, fits to a lid portion of the cassette case, contacts a ceiling wall of the box, and supports the cassette case while having a space between the external wall of the cassette case and the internal wall of the box; wherein    at least one of the upper molded member and lower molded member is provided with lateral impact absorbing blocks that protrude in an orthogonal direction to the main surface of the semiconductor wafers toward the internal wall of the box that faces the main surface; and    when a light is emitted in a perpendicular direction to the main surface of the semiconductor wafers loaded in the cassette case so as to project the lateral impact absorbing blocks, a projected image of the lateral impact absorbing blocks is positioned within a diameter width of the semiconductor wafers.    
   
   
       2 . The cushioning body for packing the cassette case according to  claim 1 , wherein: 
 the substantially rectangular upper molded member is provided with four upper impact absorbing blocks on an upper surface thereof, the blocks protruding upward from apex positions of a square; and    the substantially rectangular lower molded member is provided with four lower impact absorbing blocks on a lower surface thereof, the blocks protruding downward from apex positions of a square.    
   
   
       3 . The cushioning body for packing the cassette case according to  claim 1 , wherein two lateral impact absorbing blocks are provided on each of the upper molded member and lower molded member.  
   
   
       4 . The cushioning body for packing the cassette case according to  claim 2 , wherein two lateral impact absorbing blocks are provided on each of the upper molded member and lower molded member.