Roll-to-roll processing

In the field of electronic devices, roll-to-roll processing, also known as web processing,[1] reel-to-reel processing or R2R,[2] is the process of creating electronic devices on a roll of flexible plastic or metal foil. In other fields predating this use, it can refer to any process of applying coatings, printing, or performing other processes starting with a roll of a flexible material and re-reeling after the process to create an output roll. These processes, and others such as sheeting, can be grouped together under the general term converting. When the rolls of material have been coated, laminated or printed they can be subsequently slit to their finished size on a slitter rewinder.

In electronic devices

Large circuits made with thin-film transistors and other devices can be patterned onto these large substrates, which can be up to a few metres wide and 50 kilometres (31 mi) long. Some of the devices can be patterned directly, much like an inkjet printer deposits ink. For most semiconductors, however, the devices must be patterned using photolithography techniques.

Roll-to-roll processing of large-area electronic devices reduces manufacturing cost.[3][2] Most notable would be solar cells, which are still prohibitively expensive for most markets due to the high cost per unit area of traditional bulk (mono- or polycrystalline) 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.

LED (Light Emitting Diode)

• Inorganic LED - Flexible LED is commonly made into 25m, 50m, 100m or even longer strips using roll-to-roll process. Long neon LED tube is using such a long flexible strip and encapsulated with PVC or silicone diffusing encapsulation.
• Organic LED (OLED) - OLED for foldable phone screen is adopting roll-to-roll processing technology.

Thin-film cells

A crucial issue for a roll-to-roll thin-film cell production system is the deposition rate of the microcrystalline layer, and this can be tackled using four approaches:[4]

• very high frequency plasma-enhanced chemical vapour deposition (VHF-PECVD)
• microwave (MW)-PECVD
• hot wire chemical vapour deposition (hot-wire CVD).
• the use of ultrasonic nozzles in an in-line process

See also

• Amorphous silicon
• Low cost solar cell
• Printed electronics
• Roll slitting
• Roll-to-roll electronics inkjet printer
• Thin film solar cell
• web manufacturing

References

1. "Digital roll-to-roll web processing revolutionizes printed electronic production". Control Engineering. March 12, 2013. Retrieved February 1, 2018.
2. Goswami, Debkalpa; Munera, Juan C.; Pal, Aniket; Sadri, Behnam; Scarpetti, Caio Lui P. G.; Martinez, Ramses V. (2018-05-18). "Roll-to-Roll Nanoforming of Metals Using Laser-Induced Superplasticity". Nano Letters. 18 (6): 3616–3622. Bibcode:2018NanoL..18.3616G. doi:10.1021/acs.nanolett.8b00714. ISSN 1530-6984. PMID 29775318.
3. Wong, William S.; Salleo, Alberto, eds. (2009). "Fabrication on Web by Roll-to-Roll Processing". Flexible Electronics: Materials and Applications. New York, NY: Springer. p. 19. ISBN 978-0387743639.
4. "PV projects in FP6". Archived from the original on June 18, 2006. Retrieved 2008-11-25.

External links