Photonic curing
Photonic curing is the high-temperature thermal processing of a thin film using pulsed light from a flashlamp[1]. When this transient processing is done on a low-temperature substrate such as plastic or paper, it is possible to attain a significantly higher temperature than the substrate can ordinarily withstand under an equilibrium heating source such as an oven.[2][3] Since the rate of most thermal curing processes (drying, sintering, reacting, annealing, etc.) generally increase exponentially with temperature (i.e. they obey the Arrhenius equation), this process allows materials to be cured much more rapidly (in about 1 millisecond) than with an oven which can take minutes.
Photonic curing is used as a thermal processing technique in the manufacturing of printed electronics as it allows the substitution of glass or ceramics with inexpensive and flexible substrate materials such as polymers or paper. The effect can be demonstrated with an ordinary camera flash.[4] Industrial photonic curing systems are typically water cooled and have controls and features similar to industrial lasers. The pulse rate can be fast enough to allow curing on the fly at speeds beyond 100 m/min making it suitable as a curing process for roll-to-roll processing. Material processing rates can exceed 1 m2/sec.[5][2]
Photonic curing is similar to Pulse Thermal Processing in which a plasma arc lamp is used. In the case of photonic curing, the radiant power is higher and the pulse lengths are shorter. The total radiant exposure per pulse is less with photonic curing, but the pulse rate is much faster.[6]
Photonic Curing was developed by Nanotechnologies, Inc. (now NovaCentrix) and is incorporated into their PulseForge® tools.[7] Xenon Corporation markets photonic curing tools under the brand name Sinteron™.[8] Dresden Thin Film has also markets capabilities based on the same physics.[9] Photonic curing was introduced at the 2006 NSTI conference and is sometimes referred to as “photosintering” since nanosilver and nanocopper inks were sintered by a pulse of light from a flashlamp to form conductive traces on plastic and paper.[2] Photonic Curing has also been demonstrated to sinter high-temperature ceramics such as alumina and zirconia as well as anneal semiconductors such as amorphous silicon.[2] [10][11]
References
- ^ K. A. Schroder, Technical Proceedings of the 2011 NSTI Nanotechnology Conference and Trade Show, 2, 220-223, 2011.
- ^ a b c d K. A. Schroder, S. C. McCool, W. R. Furlan, Technical Proceedings of the 2006 NSTI Nanotechnology Conference and Trade Show, 3, 198-201, 2006.
- ^ http://http://www.rdmag.com/RD100-Awards-Flexible-Electronics-Process/
- ^ US Pat. #7,820,097.
- ^ http://www.ms.ornl.gov/mpg/pdf/researchthrusts/AP_PTPposterv2.pdf.
- ^ http://www.ms.ornl.gov/mpg/AP_ptp.shtml
- ^ http://www.novacentrix.com/product/pulseforge.php
- ^ http://www.xenoncorp.com/print_mkt.html
- ^ http://www.thin-film.de/fileadmin/medien/Website/Dokumente/Download_Center/Technische_Informationen/No2_FLA.pdf
- ^ J. West, M. Carter, S. Smith, and J. Sears, Technical Proceedings of the 2010 NSTI Nanotechnology Conference and Expo, 2, 210-213, 2010.
- ^ http://www.novacentrix.com/images/downloads/3300_Brochure_Web.pdf