Lithography on flexible substrates: a roll-to-roll high-throughput high-resolution system for low-cost production of microelectronics

We describe a novel lithography system that is capable of high-throughput projection imaging on continuous, flexible substrates in a roll-to-roll configuration. The system provides both large-area, high-resolution patterning in photoresists and via formation by photo-ablation in dielectrics, eliminating limitations of lithography tools currently used in the production of flexible circuits. The unique, modular design of the new system also provides equipment upgradability as well as choice of user-specified system configurations. These results are achieved with the combination of three key novel system features: a hexagonal seamless scanning projection imaging technology, a single- planar stage system configuration, and a roll-to-roll substrate handling system. These features provide high optical and scanning efficiencies as well as low overhead times, enabling processing throughputs as high as 4 sq. ft./min. In this paper, we describe the new lithography system concept; present the detailed system design of a recently completed machine; and discuss the key hardware subsystems, both optical and mechanical. This lithography system is highly attractive for cost-effective production of a wide variety of microelectronic products on flexible substrates, including printed circuits, multichip modules, and displays.