Ink-jet printing and camera flash sintering of silver tracks on different substrates

A camera flash-lamp, which makes use of the enhanced photothermal effect in silver nanoparticles, was used for sintering of ink-jet printed silver tracks on Polyimide (PI), Polyethylene Terephthalate (PET) and photographic paper at room temperature. After the camera flashing the nonconductive tracks was changed and became conductive. The resistivity of all tracks on different substrates was decreased after the first flashing and the second flashing, while it exhibited a slight increase after the third and forth flashing. Irrespective of the number of flashings, the silver track printed on the PET substrate had the lowest resistivity and it can reach 6.2 μΩ cm after the second flashing, while the track that was printed on the photographic paper had the highest measured resistivity due to defects in the substrate. The thermal conductivity of the substrate had an important effect on the microstructure of the silver tracks after the flashing. The nanoparticles within the tracks printed on the photographic paper exhibited significant melting after flashing sintering. This melting was due to very low thermal conductivity of the photographic paper and slow heat dissipation to the substrate and the surroundings. The nanoparticles on the PI substrate exhibited less appreciable melting due to greater thermal conductivity of the PI and fast heat dissipation to the substrate and the surroundings.