Fabrication of large-area stamps, moulds, and conformable photomasks for soft lithography

Low-cost fabrication is essential to the successful introduction of organic electronics and reel-to-reel manufacturing processes. Here it is proposed that extending flexography into the micrometre-size resolution regime may provide an economical commercialization path for plastic devices. Flexography is a high-speed technique commonly used for printing onto very large-area flexible substrates. Although low resolution and poor registration are characteristics of today’s flexographic process, it has many similarities with soft lithographic techniques. This work shows that large (12 in 12 in), high-resolution printing plates appropriate for use on small tag and label flexographic presses can be prepared using simple and inexpensive flexographiccompatible processes. This paper illustrates the use of these plates for three representative soft lithographic processes: microcontact printing, replica moulding, and phase-shift lithography.