Microstructure formation via roll-to-roll UV embossing using a flexible mould made from a laminated polymer–copper film

Abstract

Roll-to-roll large format UV embossing processes aim to revolutionize the manufacturing of functional films, with the ability to process a large area at one time, resulting in high throughput and cost reduction. In this paper, we present the experimental results obtained during the process development for roll-to-roll large format UV embossing. Flexible moulds were fabricated from a hybrid film substrate made of a liquid crystal polymer with clad copper foils laminated on both sides of it. The effective pattern area of the fabricated flexible mould was 400 mm × 300 mm with a minimal feature size of 50 µm. The results show that the roll-to-roll embossing processes are capable of producing micro-scale structures and functional devices over a large area at one time. Large-area roll-to-roll embossing was demonstrated by using the hybrid flexible mould, and micro-features and structures such as micro-channels and dot arrays were replicated on thermoplastic substrates. In addition to its ease and low cost in fabrication, the hybrid flexible moulds demonstrated to have acceptable fidelity and durability. The hybrid flexible mould is a novel solution for large-area embossing.