Large area imprinting
Process Sequence during R2R imprinting
- The entire system is located inside a laminar flow box, which guarantees a class 10.000 cleanroom environment (ISO 7 standard).
- A flexible polymer film as substrate on a roll is cleaned from particles by means of ionization and suctioning devices during the production process. If necessary, the surface to be coated may be pre-treated in a corona unit to improve wettability.
- The web edge control regulates the position of the film edge after unwinding and directly before upwinding, holds the film in a centered position and generates aligned web edges on the upwinded roller (10 micron accuracy).
- A coating step follows, whereby the liquid lacquer is applied by means of gravure printing. If necessary, the material can then be pre-dried in the thermal dryer in order to evaporate undesired solvent.
- To structure an imprint resist, two NIL processes are available: UV nanoimprint lithography (UV-NIL) for patterning UV-curable coatings and hot embossing of thermoelastic embossing resists. The hot embossing process also allows for the direct imprinting of thermoplastic foil substrates using extremely high line pressure.
- During the UV-NIL process, the structures are transferred in the liquid UV-resist; during the moment of imprinting, the lacquer is cured by UV-exposure. During the hot embossing process, the material to be embossed is heated above its glass transition temperature and, in this deformable state, is embossed through application of substantial pressure.
- The quality of the imprint result is controlled in-line using a very fast high resolution camera.
- Finally, the structured foil is upwinded. When including more complex components such as electronic ones, more complex sequences with various coating and structuring steps are necessary, because several layers of different materials must be deposited and then structured.
Facts & figures
|Web width||300 mm|
|Working width||max. 250 mm|
|Tensile strength||max. 250 N|
|Web speed||0.5 - 30 m/min|
|Corona output<br/>||max. 1000 W|
|Dryer Temperature||max. 200°C|
|UV Lamp output||max. 200 W/cm|
|Line Pressure of the UV-Imprinting Unit||max. 18 kN/Workspace Width|
|Line Pressure of the Hot Embossing Unit||max. 100 kN/Workspace Width|
|Temperature during Hot Embossing||max. 220°C|
|Laminar Flowbox||ISO 7, Cleanroom Class 10.000|