Optimization of plasma preparation of polymeric substrate for embedded flexible electronic applications

Abstract

An optimization of process parameters of inductively coupled plasma reactive ion etching (ICP-RIE) was obtained for polyethylene naphthalate (PEN) substrate, which is popularly used for flexible electronics. Comparing to conventional electronic devices, people expect better mechanical and chemical reliability and integrity when the electronic circuitry or systems are embedded in the polymer substrate by dry etching processes. The optimized etching process greatly improved the polymer substrate’s surface roughness (Rq) by 93%, improved its optical transmittance by 10.4% on average in the visible region, and improved its efficiency by 6-fold compared to generally used parameters. By matching the ICP-RIE’s generator power, platen power, and reaction gas ratio, this study achieved a faster etching rate, lighter damage, and higher optical transmittance on PEN. This etching process studied in this work expedites the realization of embedded electronics in a polymer substrate with greatly improved necessary properties and implies around 50% finer linewidth with smaller surface energy.