Roll-to-roll processing

Roll-to-roll processing, also known as 'web' processing, is the process of creating electronic devices on a roll of flexible plastic or metal foil. Large circuits made with thin-film transistors and other devices can be easily patterned onto these large substrates, which can be up to a few metres wide and 50 km long. Some of the devices can be patterned directly, much like an ink-jet printer deposits ink. For most semiconductors, however, the devices must be patterened using photolithography techniques.

Roll-to-roll processing is a technology which is still in development. If solid-state devices can be fabricated in this way on large substrates, many devices could be fabricated at a fraction of the cost of traditional semiconductor manufacturing methods. Most notably would be solar cells, which are still prohibitively expensive for most markets, due to the high-cost per unit area of traditional crystalline silicon manufacturing. Other applications could arise, which take advantage of the flexible nature of the substrates, such as electronics embedded into clothing, large-area flexible displays, and roll-up portable displays.