TITLE:
The Effect of Laser Sintering Process Parameters on Cu Nanoparticle Ink in Room Conditions
AUTHORS:
Eerik Halonen, Esa Heinonen, Matti Mäntysalo
KEYWORDS:
Nanoparticles; Electrical Properties; Laser Processing; Microstructure; Sintering; Thin Films
JOURNAL NAME:
Optics and Photonics Journal,
Vol.3 No.4A,
August
9,
2013
ABSTRACT: Copper is an interesting
material for printed electronics inks because, for example, of its good
conductivity and lower raw material price compared to silver. However,
post-processing Cu inks is challenging because of non-conductive copper oxide.
In this work, inkjet-printed Cu nanoparticle structures were sintered on a
polyimide substrate with a continuous-wave 808-nm diode laser. Laser sintering
was tested by varying the sintering parameters (optical power and scanning
velocity), and the electrical resistance of the samples was measured. A minimum
sheet resistance of approx.90 mΩ/□
was obtained. All tests were run in room conditions. Sintered structures were
then analyzed from SEM images. Results showed that laser sintering produces
good repeatability, that a scanning velocity increment positively affects the
process window, and that multiple sintering cycles do not increase
conductivity.