1 research outputs found
Hybrid Copper–Silver Conductive Tracks for Enhanced Oxidation Resistance under Flash Light Sintering
We
developed a simple method to prepare hybrid copper–silver conductive
tracks under flash light sintering. The developed metal nanoparticle-based
ink is convenient because its preparation process is free of any tedious
washing steps. The inks were composed of commercially available copper
nanoparticles which were mixed with formic acid, silver nitrate, and
diethylene glycol. The role of formic acid is to remove the native
copper oxide layer on the surface of the copper nanoparticles. In
this way, it facilitates the formation of a silver outer shell on
the surface of the copper nanoparticles through a galvanic replacement.
In the presence of formic acid, the copper nanoparticles formed copper
formate, which was present in the unsintered tracks. However, under
illumination by a xenon flash light, the copper formate was then converted
to copper. Moreover, the resistance of the copper-only films increased
by 6 orders of magnitude when oxidized at high temperatures (∼220
°C). However, addition of silver nitrate to the inks suppressed
the oxidation of the hybrid copper–silver films, and the resistance
changes in these inks at high temperatures were greatly reduced. In
addition, the hybrid inks proved to be advantageous for use in electrical
circuits as they demonstrated a stable electrical conductivity after
exposure to ambient air at 180 °C