Photonic sintering of nano-silver conductive ink for printed electronics
Gu W., Cui Z.
© 2016 IEEE. Infrared (IR) sintering as one of photonic sintering technologies has exploited the possibility of application in roll to roll manufacture, because it can sinter metal nanoparticles (NPs) ink in seconds and in large area. Here, we demonstrated near-infrared (NIR) sintering of silver NPs ink with peak wavelength of 1100nm. The volume resistivity of sintered film were decreased exponentially as the irradiation power increased. Minimum resistivity of 2.78μω.cm, which corresponds to 1.6 times of that of bulk silver, was achieved in 8 seconds of irradiation. The reflectance of the silver NPs film was enhanced during the sintering, creating a negative feedback and benefiting to prevent thermal loading. Also, the uniformity of NIR sintering was investigated with different thickness of silver NPs film from 1.7μm to 7μm. Finally, a conductive pattern on PEN (polyethylene terephthalate) substrate was fabricated by screen printing and sintered by NIR without damaging the polymer substrate.