A low cost direct writing process for flexible circuit and interconnect fabrication
Watson, David Ewan Gray
MetadataShow full item record
This thesis investigates the development of a low cost fabrication process for flexible electronics and interconnects. By using a ‘direct writing’ process, the use of vacuum-‐based metal evaporation and photoresist steps is not necessary and so less complex equipment is needed. The process forms silver embedded on top of a polyimide substrate and was first tested using a UV laser to perform writing before switching to a blue laser due to excessive substrate degradation observed from UV exposures. The blue light was combined with a biologically friendly photo reducing agent, which was found to be much more efficient at the creation of silver. The methods of silver formation by various means are the main focus of investigation in this thesis but process expansion and improvement were the main goals. To this end, a chemical, rather than light-‐based, process for silver creation was found to produce more consistent silver coatings, however the patterning by this method was found to be more challenging. The process was also extended to a different substrate in polyetherimide.