Editing Roll-to-roll processing (section)

== In electronic devices ==
Large [[Integrated circuit|circuit]]s made with [[thin-film transistor]]s and other devices can be [[pattern]]ed onto these large substrates, which can be up to a few metres wide and {{convert|50|km|abbr=on}} long.{{citation needed|date=March 2017}}  Some of the devices can be patterned directly, much like an [[inkjet printer]] deposits ink.  For most [[semiconductor]]s, however, the devices must be patterned using [[photolithography]] techniques.
[[File:Roll tol rol slitting processing.jpg|alt=roll to roll processing|thumb|roll to roll processing]]
Roll-to-roll processing of large-area electronic devices reduces manufacturing cost.<ref>{{cite book|chapter-url=https://books.google.com/books?id=ZiGjrlkSpOQC&q=%22web+processing%22+%22Roll+to+roll%22&pg=PA19|title=Flexible Electronics: Materials and Applications|chapter=Fabrication on Web by Roll-to-Roll Processing|page=19|editor1=Wong, William S. |editor2=Salleo, Alberto|publisher=Springer|place=New York, NY|year=2009|isbn=978-0387743639}}</ref><ref name=":0" />  Most notable would be [[solar cell]]s, which are still prohibitively expensive for most markets due to the high cost per unit area of traditional bulk ([[Monocrystalline silicon|mono-]] or [[Polycrystalline silicon|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 [[rollable display|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 (physics)|deposition]] rate of the [[microcrystalline]] layer, and this can be tackled using four approaches:<ref>{{cite web |url=http://ec.europa.eu/research/energy/nn/nn_rt/nn_rt_pv/article_1109_en.htm |title=PV projects in FP6 |accessdate=2008-11-25 |url-status=dead |archiveurl=https://web.archive.org/web/20060618111512/http://ec.europa.eu/research/energy/nn/nn_rt/nn_rt_pv/article_1109_en.htm|archivedate=June 18, 2006 }}</ref>
*very high frequency  plasma-enhanced chemical vapour deposition ([[VHF]]-[[PECVD]])
*microwave ([[Microwave|MW]])-PECVD
*hot wire [[chemical vapour deposition]] (hot-wire CVD)
*the use of [[ultrasonic nozzle]]s in an in-line process