Fabrication and Optimization of Roll‐To‐Roll <scp>UV</scp> ‐Embossed Microlens Array– <scp>PDLC</scp> Films for Enhanced Light Extraction in <scp>OLED</scp> Panels

ABSTRACT This study presents developing and optimizing a roll‐to‐roll (R2R) UV embossing process for high‐volume, low‐cost fabrication of microlens array–polymer dispersed liquid crystal (MLA‐PDLC) composite films. The relative influence of process parameters was systematically quantified by employing Taguchi experimental design. Film‐press pressure was identified as the dominant factor governing replication fidelity, followed by film tension and resin temperature, while film speed had minimal effect. Optimized conditions (resin temperature 25°C, film speed 0.6 m/min, press pressure 190 MPa, and tension 40 N) yielded replication fidelity of 96.2%, with only 1.49% deviation from prediction, confirming the robustness and reproducibility of the process optimization. A more economical approach was introduced to address the cost and scalability limitations of conventional embossing roller fabrication by combining 3D‐printed masters with a polydimethylsiloxane (PDMS) soft mold laminated onto the roller surface. This strategy significantly reduces tooling costs while maintaining high replication accuracy, demonstrating strong potential for industrial‐scale deployment. Validation on OLED lighting panels confirmed the practical benefits of the optimized MLA‐PDLC films, including enhanced luminous flux, luminance, and illuminance uniformity. These results highlight that achieving high replication fidelity is critical for optical performance and establishing a reliable, scalable, and cost‐effective manufacturing route for advanced microstructured films.