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, metal foil, or flexible glass.^[3] In other fields predating this use, it can refer to any process of applying coating, 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 meters wide and 50 kilometres (31 mi) long.^{[citation needed]} 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.^[4][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 25, 50, 100 m, or even longer strips using a roll-to-roll process. A 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:^[5]

• 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

In electrochemical devices

The roll-to-roll processing has been used in the manufacture of electrochemical devices such as batteries,^[6] supercapacitors,^[7] fuel cells,^[8][9] and water electrolyzers.^[10] Here, the roll-to-roll processing is utilized for electrode manufacturing and is the key to reducing manufacturing cost^[11] through stable production of electrodes on various film substrates such as metal foils, membranes, diffusion media, and separators.

See also

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

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. Tamagaki, Hiroshi; Ikari, Yoshimitu; Ohba, Naoki (2014). "Roll-to-roll sputter deposition on flexible glass substrates". Surface and Coatings Technology. 241: 138–141. doi:10.1016/j.surfcoat.2013.10.056 – via ResearchGate.
4. 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.
5. . Archived from the original on June 18, 2006. Retrieved 2008-11-25.
6. US11446915B2, Biswas, Kaushik; III, David Lee Wood & Grady, Kelsey M. et al., "Roll-to-roll slot die coating method to create interleaving multi-layered films with chemical slurry coatings", issued 2022-09-20 
7. Yeo, Junyeob; Kim, Geonwoong; Hong, Sukjoon; Kim, Min Su; Kim, Daewon; Lee, Jinhwan; Lee, Ha Beom; Kwon, Jinhyeong; Suh, Young Duk; Kang, Hyun Wook; Sung, Hyung Jin; Choi, Jun-Ho; Hong, Won-Hwa; Ko, Jang Myoun; Lee, Seung-Hyun (2014-01-15). "Flexible supercapacitor fabrication by room temperature rapid laser processing of roll-to-roll printed metal nanoparticle ink for wearable electronics application". Journal of Power Sources. 246: 562–568. Bibcode:2014JPS...246..562Y. doi:10.1016/j.jpowsour.2013.08.012. ISSN 0378-7753. S2CID 94203734.
8. Steenberg, Thomas; Hjuler, Hans Aage; Terkelsen, Carina; Sánchez, María T. R.; Cleemann, Lars N.; Krebs, Frederik C. (2012-03-01). "Roll-to-roll coated PBI membranes for high temperature PEM fuel cells". Energy & Environmental Science. 5 (3): 6076–6080. doi:10.1039/C2EE02936G. ISSN 1754-5706. S2CID 95139481.
9. Mauger, Scott A.; Neyerlin, K. C.; Yang-Neyerlin, Ami C.; More, Karren L.; Ulsh, Michael (2018-09-11). "Gravure Coating for Roll-to-Roll Manufacturing of Proton-Exchange-Membrane Fuel Cell Catalyst Layers". Journal of the Electrochemical Society. 165 (11): F1012. doi:10.1149/2.0091813jes. ISSN 1945-7111. S2CID 105303844.
10. Park, Janghoon; Kang, Zhenye; Bender, Guido; Ulsh, Michael; Mauger, Scott A. (2020-12-15). "Roll-to-roll production of catalyst coated membranes for low-temperature electrolyzers". Journal of Power Sources. 479: 228819. Bibcode:2020JPS...47928819P. doi:10.1016/j.jpowsour.2020.228819. ISSN 0378-7753. S2CID 224915162.
11. Mauler, Lukas; Duffner, Fabian; Leker, Jens (2021-03-15). "Economies of scale in battery cell manufacturing: The impact of material and process innovations". Applied Energy. 286: 116499. doi:10.1016/j.apenergy.2021.116499. ISSN 0306-2619. S2CID 233658321.