EnFACE: a maskless process for circuit fabrication

Purpose - The purpose of the paper is to present an update and the latest results from work on a project which could be useful for maskless printed circuit board (PCB) manufacturing. Design/methodology/approach - Copper is plated and etched using a novel electrochemical technique, electrochemical patterning by flow and chemistry, using a masked tool and fully exposed substrate. The micro patterns on the tool are replicated on the substrate via optimum design of the apparatus, choice of electrolyte chemistry and fluid flow. Findings - Linear and square shapes ranging from 5 to 200 μm are transferred using the technique by electrochemical plating and etching. Up to 25 substrates could be processed using a single tool, which indicates that photolithography requirements can be greatly minimised. Research limitations/implications - The copper lines are transferred to relatively small substrates. The process needs to be scaled up to accommodate larger substrates in order to fully exploit its potential for PCBs. Originality/value - The paper presents a fundamentally different approach to transfer micron scale pattern using a maskless technology. The platform technology involves using a mask to pattern each substrate; this work shows that micron scale patterns can be transferred without masking by optimising electrochemical reactor technology.