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 x 12 in), high-resolution printing plates appropriate for use on small tag and label flexographic presses can be prepared using simple and inexpensive flexographic-compatible processes. This paper illustrates the use of these plates for three representative soft lithographic processes: microcontact printing, replica moulding, and phase-shift lithography.