Process for thick film circuit patterning

Abstract

A process for patterning thick film electrically functional patterns using a photosensitive polymer layer. A tacky photosensitive layer is applied onto a substrate surface. The photosensitive layer is imaged with a pattern using actinic radiation, the exposed areas of the photosensitive layer become hardened and non-tacky. A subsequent application of a thick film composition sheet will cause the thick film to adhere to the remaining tacky areas. Upon peeling the sheet, a thick film print pattern will be produced. This step is followed by a processing profile prescribed by the thick film composition used which results in a pattern having electrically functional properties. The invention also extends to a process wherein a thick film composition is recovered from a used sheet.

1 - 14 . (canceled) 
   
   
       15 . An intermediate having a pattern for forming electrically functional properties comprising an imaged layer having tacky and non-tacky areas disposed on a substrate which areas are in contact with a thick film composition disposed on a support. 
   
   
       16 . The intermediate of  claim 15  wherein the thick film composition comprises a fireable thick film composition. 
   
   
       17 . The intermediate of  claim 15  wherein the thick film composition comprises an adhesion promoter which allows the composition to have greater adhesion to the tacky surface than to the support. 
   
   
       18 . The intermediate of  claim 17  wherein the adhesion promoter is oxalic acid catalyzed alkyl t-butyl/amyl phenolic resin. 
   
   
       19 . The intermediate of  claim 15  wherein the imaged layer comprises a photosensitive composition. 
   
   
       20 . The intermediate of  claim 15  wherein the thick film composition is a polymer thick film composition. 
   
   
       21 - 24 . (canceled) 
   
   
       25 . A system for forming a circuit pattern comprising:
 (a) a photosensitive layer; and   (b) a sheet having a thick film composition which imparts electrically functional properties applied thereto.   
   
   
       26 . The system of  claim 25  wherein the thick film composition is a fireable thick film composition. 
   
   
       27 . The system of  claim 25  wherein the thick film composition comprises an adhesion promoter which allows the composition to have greater adhesion to the tacky surface than to the support. 
   
   
       28 . The system of  claim 25  wherein the adhesion promoter is an oxalic acid catalyzed alkyl t-butyl/amyl phenolic resin. 
   
   
       29 . The system of  claim 25  wherein the photosensitive layer is photohardenable. 
   
   
       30 . A device formed by the process of claim  1 .