Nanoimprint lithography  is a verified production technology for a variety of applications, from creating microlenses  to use in the production of vertical-cavity surface-emitting lasers (VCSELs) .
Nanoimprint is executed on the wafer-scale in most of these applications. Roller-based nanoimprint has been suggested very early on for larger areas . Roll-to-roll based nanoimprint  has undergone several developments. However, in the case of roll-to-plate NIL utilizing rigid substrates, much less has been refined.
To solve the limitations of large area nanoimprinting on opaque and rigid substrates, Stensborg has developed a roll-to-plate nanoimprint tool based on UV light. It is established on our patented concept  and includes a transparent roller and a substrate translation stage. A translucent printing plate or stamp can be connected to the roller. This roller contains the source of the UV light. A range of UV-LEDs emits light, which is directed to the nip. The nip is the place where the roller and the substrate meet.
Devices currently produced and installed manage substrates with sizes of up to 30 x 60 cm2 and plate thickness of up to 10 mm. The printing speed can vary from 1 to 10 meters per minute. Slot die coating and inkjet printing equipment are options that can be installed to include coating abilities for large areas.
Stensborg has performed initial imprinting tests. To carry out these investigations, a glass substrate was fixed onto the granite substrate table. A polymer foil was attached to the glass substrate and a UV-curable imprint material is applied with slot die coating.
Figure 1. Linescan (Profilometer) of a roll-to-plate imprinted micro optical test structure, feature height approximately 45 µm, period approximately 100 µm. Image Credit: Stensborg
Figure 2. Linescan (AFM) of a roll-to-plate imprinted holographic test structure, feature height approximately 350 nm, period approximately 880 nm. Image Credit: Stensborg
Characteristics with a broad variety of dimensions were replicated successfully. Figure 1 shows a line scan of a micro-optical test structure, and a line scan of a test-hologram is shown in Figure 2.
Figure 3. Optical micrograph of a hologram test pattern corresponding to Figure 2. Image Credit: Profaktor
Figure 4. Photograph of the roller during imprinting with a printing plate mounted to the roller. Image Credit: Profaktor
The period of the features along with the height vary by multiple orders of magnitude. A standard printed hologram structure is demonstrated in Figure 3. An image of the device throughout UV-imprinting, including the imprinting plate, can be seen in Figure 4.
Due to the material combinations that were evaluated, the separation was very effective. It was not necessary to adhere the polymer foils on the glass substrate to enable effective separation followoing the imprinting.
Imprinting plates produced from a UV-curable resin material or UV-curable PDMS were used along with X29 imprinting resist from Stensborg. In both combinations, the separation was instant, so the foil isolated itself from the imprinting plate.
Stensborg will publish additional imprinting results with a larger range of micro- and nanoscale characteristics, and also the further results from a large area coating of UV-curable materials.
Produced from materials originally authored by L. Yde1, L. Lindvold1, J. Stensborg1, T. Voglhuber2, H. Außerhuber2, S. Wögerer2, T. Fischinger2, M. Mühlberger2, and W. Hackl3from Stensborg1, PROFACTOR GmbH2 and Forster Verkehr- und Werbetechnik GmbH3.
References and Further Reading
 Chou, S.Y., et al., J Vac Sci Technol B 14 (1996) 4129.
 Haisma, J., et al. J Vac Sci Technol B 14 (1996), 4124.
 Schift, H., J Vac Sci Technol B26 (2008) 458.
 Heptagon, (accessed 4.4.2016)
 Verschuuren, M.A., presented at NNT2011
 Tan, H., et al,. J Vac Sci Technol B 16 (1998) 3926.
 Thesen, M.W., et al. Microel Eng 123 (2014) 121.
 Ahn, S.H., et al., Advanced Materials 20 (2008) 2044.
 John, J., et al., Nanotechnology 24 (2013) 505307.
 Lindvold, L., Stensborg, J., Rasmussen, T., EP 1150843 B2.
This information has been sourced, reviewed and adapted from materials provided by Stensborg.
For more information on this source, please visit Stensborg.