Packaging system for protection of ic wafers during fabrication, transport and storage

Abstract

The packaging system includes an enclosure having an interior volume. A wafer stack, comprising plural wafers and separators in contact with the wafers, is located in the interior volume. The separators have raised bumps extending from each side. The bumps create spaces that allow air to flow therethrough. The separator film intercepts and captures airborne molecular contaminants belonging to organic and inorganic chemical families. In addition, the film is dissipative to static discharge. Furthermore, the bumps provided by the separators protect the fragile wafers from damage due to mechanical shock. The separators are also provided with a peripheral ring or embossment, which contacts the wafer edges and further protects the wafers from damage to mechanical shock. Air cushions can be provided in the wafer stack, which cushions are provided with bands to regulate the compression.

1 . A packaging system for intercepting and capturing mechanical shock energy and corrosive contaminants for the protection of IC wafers during fabrication, transport, and storage phases, such wafers having surface components such as bond pads, solder balls and interconnects which are susceptible to damage due to corrosion, mechanical shock or electrical static discharge, comprising:
 a) an enclosure having an interior volume;   b) a wafer stack located in the interior volume, the wafer stack comprising plural wafers and separators in contact with the wafers, the separators are sheets each having two sides and having raised bumps extending from each side of the separator sheet, the bumps creating spaces between the respective separator and the respective wafer, which spaces allow air to flow there through;   c) at least one of the separators made of a polymer film material having the properties to intercept and capture airborne molecular contaminants (AMCs) belonging to either or both chemical organic and inorganic families for which said material is dissipative to static discharge.   
     
     
         2 . The package of  claim 1  wherein the separator is static dissipative made of a plastic film material having at least two layers with one comprising of activated carbon and the second layer having a component taken from the metallic group of copper, aluminum, tin, silver and a rare earth. 
     
     
         3 . The packaging system of  claim 1 , wherein:
 a) the wafers have edges subject to mechanical shock;   b) the separators are sheets, the separators have peripheral rings located adjacent to the wafer edges so as to protect each associated packaged wafer edge from shock or physical damage.   
     
     
         4 . The packaging system of  claim 3  wherein the peripheral rings are embossed in the separator sheets. 
     
     
         5 . The packaging system of  claim 3  further comprising a rigid support ring made of a polymer located adjacent to the separator, the wafers being supported by the support ring. 
     
     
         6 . The packaging system of  claim 2 , further comprising:
 a) at least one cushion located in the wafer stack, the cushion comprises a compressible core and a flexible envelope around the core, the envelope having vents to allow gas to pass in and out of the top and bottom cushions at a controlled rate, the top and bottom cushions having sidewalls that compress when the top and bottom cushions are compressed;   b) a flexible band around the side wall of at least one of the top and bottom cushions, the band located outside of the cushion envelope and controlling the flow of gas into and out of the respective cushion.   
     
     
         7 . The packaging system of  claim 1  wherein the enclosure is a plastic rigid ho having insulative surfaces. 
     
     
         8 . The packaging system of  claim 7  wherein the wafer stack is dissipative to static discharge. 
     
     
         9 . The packaging system of  claim 7 , wherein:
 a) the arrangement of packaged wafers, separators and cushions all having dissipative surfaces will provide electrical path to earth ground;   b) the box can be stacked onto similar boxes;   c) the box having top and bottom conductors on the outside and providing an electrical path to earth ground for the wafer stack;   d) the top or bottom conductors being m contact with the to or bottom conductors of an adjacent box stacked with the one box.   
     
     
         10 . The packaging system of  claim 1  wherein the enclosure is a bag. 
     
     
         11 . The packaging system of  claim 1  wherein the enclosure is a rigid box within a bag. 
     
     
         12 . (canceled) 
     
     
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         17 . (canceled)