US Patent 7741013 Process for thick film circuit patterning

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.