Dimensionally stable composite article

Abstract

A composite article having large scale predictable dimensional stability comprises a metal foil backing having adhered thereto a layer of cured polymer having an exposed surface bearing a three-dimensional microstructure of precisely shaped and located functional discontinuities. The article is made by depositing a layer of a radiation curable composition onto a metal foil backing, contacting a master with a pattern capable of imparting a three-dimensional microstructure of precisely shaped and located functional discontinuities into the layer of radiation curable composition, while the layer of radiation curable composition is in contact with the master, exposing the curable composition to radiation to cure the composition, and separating the cured polymer layer on the metal foil backing from the surface of the master. Either the metal foil backing or the master may be radiation transmissive.

We claim:  
     
         1 . A composite article having large scale predictable dimensional stability comprising: 
 a. a metal foil backing having a back surface and an opposite front surface; and    b. a layer of a radiation cured polymer having an exposed front surface bearing a three-dimensional microstructure of precisely shaped and located functional discontinuities including distal surface portions and adjacent depressed surface portions and an opposite surface in adherent contact with the front surface of said backing.    
     
     
         2 . The composite article of  claim 1  wherein said metal foil backing comprises a metal selected from the group consisting of copper, aluminum, zinc, titanium, tin, iron, nickel, gold, silver, combinations thereof and alloys thereof.  
     
     
         3 . The composite article of  claim 1  wherein said radiation cured polymer is a cured oligomeric resin.  
     
     
         4 . The composite article of  claim 1  wherein said radiation cured polymer is cured by electron beam radiation and said metal foil backing is e-beam radiation transmissive.  
     
     
         5 . The composite article of  claim 1  wherein said radiation cured polymer is cured by actinic radiation.  
     
     
         6 . The composite article of  claim 1  wherein said radiation cured polymer is cured by thermal radiation.  
     
     
         7 . The composite article of  claim 1  wherein the depressed areas are wells which are shaped for receiving and holding complementarily shaped articles.  
     
     
         8 . The composite article of  claim 7  in which the cavities are shaped to receive gyricon spheres.  
     
     
         9 . The composite article of  claim 2  wherein the metal foil comprises a metal selected from the group consisting of copper and aluminum.  
     
     
         10 . The composite article of  claim 7  in which the cavities are shaped to receive conductive spheroids.  
     
     
         11 . A composite article having large scale predictable dimensional stability comprising: 
 a. a metal foil backing having a back surface and an opposite front surface; and    b. a layer of a radiation cured polymer having an exposed front surface bearing a three-dimensional microstructure of precisely shaped and located interactive functional discontinuities including distal surface portions and adjacent depressed surface portions and an opposite surface in adherent contact with the front surface of said backing.    
     
     
         12 . The composite article of  claim 11  wherein at least one portion of the polymer layer includes a distal surface portion distally spaced at least 0.05 mm from an adjacent depressed surface portion.  
     
     
         13 . The composite article of  claim 11  wherein said metal foil backing comprises a metal selected from the group consisting of copper, aluminum, zinc, titanium, tin, iron, nickel, gold, silver, combinations thereof and alloys thereof.  
     
     
         14 . The composite article of  claim 11  wherein said radiation cured polymer is a cured oligomeric resin.  
     
     
         15 . The composite article of  claim 11  wherein said radiation cured polymer is cured by electron beam radiation and said metal foil backing is e-beam radiation transmissive.  
     
     
         16 . The composite article of  claim 11  wherein said radiation cured polymer is cured by actinic radiation.  
     
     
         17 . The composite article of  claim 11  wherein said radiation cured polymer is cured by thermal radiation.  
     
     
         18 . The composite article of  claim 11  wherein the depressed areas are cavities which are shaped for receiving and holding complementarily shaped articles.  
     
     
         19 . The composite article of  claim 18  in which the cavities are shaped to receive gyricon spheres.  
     
     
         20 . The composite article of  claim 13  wherein the metal foil comprises a metal selected from the group consisting of copper and aluminum.  
     
     
         21 . The composite article of  claim 18  in which the cavities are shaped to receive conductive spheroids.  
     
     
         22 . The composite article of  claim 18  wherein the microstructure is shaped to provide an article which is useful as an etch mask.  
     
     
         23 . The composite article of  claim 1  having a dimensional change of less than about 100 ppm.  
     
     
         24 . The composite article of  claim 1  having a dimensional change of less than about 60 ppm.  
     
     
         25 . The composite article of  claim 11  having a dimensional change of less than about 100 ppm.  
     
     
         26 . The composite article of  claim 11  having a dimensional change of less than about 60 ppm.