Roll‐to‐roll manufacturing of electronics on flexible substrates using self‐aligned imprint lithography (SAIL)

TLDR

Roll‑to‑roll manufacturing of large‑area thin‑film transistor arrays on polymer substrates is being developed, but challenges arise from flexible substrates and toolset design, and self‑aligned imprint lithography (SAIL) offers submicron patterning and alignment in this environment. This paper presents the SAIL process methods, the resulting active‑matrix backplanes, the development trajectory, and the remaining production issues. SAIL achieves precise interlayer registry on a moving web by encoding all pattern geometry into a monolithic 3‑D imprint with discrete thickness modulation, and its pre‑aligned multi‑step mask structure preserves alignment despite substrate distortion.

Abstract

Abstract— The manufacture of large‐area arrays of thin‐film transistors on polymer substrates using roll‐to‐roll (R2R) processes exclusively is being developed. Self‐aligned imprint lithography (SAIL) enables the patterning and alignment of submicron‐sized features on meter‐scaled flexible substrates in the R2R environment. SAIL solves the problem of precision interlayer registry on a moving web by encoding all the geometry information required for the entire patterning steps into a monolithic three‐dimensional imprint with discrete thickness modulation. The pre‐aligned multiple‐step mask structure maintains its alignment regardless of subsequent substrate distortion. Challenges are encountered in relation to the novel nature of using flexible substrates and building toolsets for the R2R processing. In this paper, methods of the SAIL process, the resulting active‐matrix backplanes, the trajectory of SAIL process development, and the remaining issues for production are presented.