Neue Aufbau- und Verbindungstechnik für zuverlässige biegbare Elektronik - HyPerStripes; Teilvorhabensbezeichnung für EMFT: Rolle-zu-Rolle Technologie für zuverlässige biegbare Elektronik

Abstract

"HyPerStripes - Digital roll-to-roll lithography with precision stitching for meter-scale flexible interconnects" within the HyPerStripes consortium was carried out and successfully completed as planned in the project description. A novel direct-write, step-and-repeat R2R lithography with algorithmic alignment and stitching compensation was designed, implemented, and validated on polyimide (PI) and thermoplastic polyurethane (TPU). The function and benefits of the process were demonstrated together with the project partners Philips, Capical, and Osypka using three implemented technology demonstrators. The technology achieves registration accuracy ≤2 µm with ~4 µm seam offset over 1–1.5 m stripes, supporting 150–400 µm lines, 100–300 µm spacing, and 8–9 µm copper thickness. Two mature process flows were established: a semi-additive plating route on PI enabling double-sided structures and laser vias, and a wet-etch route on Cu-laminated TPU with stable R2R handling, post-etch frame support, and PU passivation. Electrical tests confirmed reproducible DC performance and robust high-frequency behavior around 30 MHz (characteristic impedance ~81–87 Ω) with manageable crosstalk trade-offs, enabling compact foil-based wiring as an alternative to bulky high-speed cable harnesses. The developed technologies and processes open new application fields for scalable, cost-efficient long interconnects in medical technology and beyond. Next steps toward industrialization include R2R encapsulation (coverlay/digital print), qualification of multilayer TPU with vias, increased automation and throughput, and standardized DC/HF and reliability qualification for series deployment.