Flexible electronics are increasingly being used in a number of applications which benefit from their low profile, light weight, and favorable dielectric properties. However, despite these advantages, the range of practical, high-volume, applications for flexible electronics will remain limited in the future unless a number of challenges related to lithographic patterning on flexible substrates are successfully addressed. The most critical of these pertain to system parameters that affect the cost and performance of flexible circuits, including the resolution, panel size, process throughput, substrate distortion, material handling, and yield. We present a new class of roll-to-roll lithography systems, developed in recent years, that were designed to address the challenges in each of these critical areas. These systems provides high-resolution projection imaging over very large exposure areas, on flexible substrate materials. Additionally, they achieve high-precision alignment by means of image scaling to compensate for substrate distortion due to processing; and they also performs high-throughput photoablation, patterning millions of pixels simultaneously, by means of projection imaging. This technology is attractive for current and emerging applications, such as flexible circuit boards and flexible chip carriers, as well as for potential future applications such as such as flexible displays and macroelectronic systems.

An important requirement in the production of numerous microelectronic, optoelectronic, and microsystem devices is lithographic patterning on a large area with high image resolution and precise layer-to-layer alignment. Whereas for production of semiconductor devices advances have been steadily made in steppers and other conventional lithography systems, the lithography requirements for the fabrication of large-format products, such as displays, multilayer circuits, and flexible electronics, are distinctly different, rendering various conventional lithography tools inadequate. These requirements and distinctions of large-area lithography are discussed. In the last several years, we have developed a new class of projection lithography systems that provide both high-resolution imaging and very large exposure area capability with high-precision alignment. The systems, using excimer laser sources, function as dual-mode, high-throughput production tools, capable of patterning in photoresists as well as photoablation in polymers, making them attractive for production of numerous large-format products, with feature sizes ranging from 15 /spl mu/m to below 1 /spl mu/m and substrate sizes ranging from 150 /spl times/ 150 mm to 610 /spl times/ 915 mm. We review the new lithography system technology, several completed systems, and demonstrated results.