Method for making a film cassette for gaseous vapor deposition

Abstract

The present invention is a method for making a film cassette end plate and a film cassette comprises two end plates. The uncoated end plates are formed using one of several known plastic forming methods. The end plates are coated with an inorganic coating to impart smoothness and hardness to facilitate film handling and reduce wear. The end plates are mounted on a shaft to form a cassette.

1 . A process for making the end plate of a cassette for supporting a length of film during exposure to a gaseous fluid having a temperature 80 degrees centigrade or greater comprising the steps of:
 a) forming an end plate of polymer wherein the end plate comprises a central hub, an outer rim, and a rib, the hub and the outer rim being connected by a plurality of spaced spokes having an interior surface, the rib being formed in a spiral fashion to the interior surface of the spokes;   b) optionally, heat treating the end plate; and   c) coating the end plate with an inorganic coating, the coating having a surface roughness less than about fifty microns (50 microns) and a hardness greater than Shore D 30.   
     
     
         2 . The process of  claim 1  wherein the polymer has a heat distortion temperature at a load of 0.46 MPa above 80 degrees centigrade. 
     
     
         3 . The process of  claim 1  wherein the polymer is selected from the group consisting of polycarbonate, liquid crystals, polyimid, acetal copolymer, acrylic, Nylon 6, polyethylene, polypropylene and PEEK. 
     
     
         4 . The process of  claim 1  wherein the forming of the end plate is by rapid prototyping, powder sintering, injection molding or laser polymerization. 
     
     
         5 . The process of  claim 1  wherein the inorganic coating is alumina, silicon nitride, or silicon carbide. 
     
     
         6 . The process of  claim 1  wherein the coating of the inorganic coating is by chemical vapor deposition, physical vapor deposition, or plasma deposition. 
     
     
         7 . The process of  claim 1  wherein the central shaft is slotted. 
     
     
         8 . A process for making a cassette for supporting a length of film during exposure to a gaseous fluid having a temperature 80 degrees centigrade or greater comprising the steps of:
 a) forming two end plates of polymer wherein the end plates each comprise a central hub, an outer rim, and a rib, the hub and the outer rim being connected by a plurality of spaced spokes having an interior surface, the rib being formed in a spiral fashion to the interior surface of the spokes and the rib having an end of the spiral;   b) optionally, heat treating the two end plates;   c) coating the end plates with an inorganic coating, the coating having a surface roughness less than about fifty microns (50 microns) and a hardness greater than Shore D 30;   d) mounting the end plates on both ends of a central shaft having two ends such that the interior surface of the spokes face each other; and   e) aligning the ribs of both end plates such that the end of the spiral on both end plates is at the same radial position.   
     
     
         9 . The process of  claim 8  wherein the polymer has a heat distortion temperature at a load of 0.46 MPa above 80 degrees centigrade. 
     
     
         10 . The process of  claim 8  wherein the polymer is selected from the group consisting of polycarbonate, liquid crystals, polyimid, acetal copolymer, acrylic, Nylon 6, polyethylene, polypropylene and PEEK. 
     
     
         11 . The process of  claim 8  wherein the forming of the end plate is by rapid prototyping, powder sintering, injection molding or laser polymerization. 
     
     
         12 . The process of  claim 8  wherein the inorganic coating is alumina, silicon nitride, or silicon carbide. 
     
     
         13 . The process of  claim 8  wherein the coating of the inorganic coating is by chemical vapor deposition, physical vapor deposition, or plasma deposition. 
     
     
         14 . The process of  claim 8  wherein the central shaft is slotted.