Laser sintering of the printed silver ink

Because flexible electronics have a weak characteristic in high temperature, the conductive ink including nano-metal particles is printed on flexible substrate by printing methods such as screen printing, inkjet printing, and R2R. Due to high electrical resistance of printed metal ink, the process to improve the property of electrical conductivity is needed. To improve the conductivity, the furnace curing is used after printing the ink on the substrate. But this process spends much time for curing. Therefore, flexible substrate or glass substrate can be damaged due to long exposed time. The curing by using a laser is utilized to minimize the damage of flexible substrate. In this work, the specific resistance of silver ink by using furnace curing at the temperature of 250°C after 30 minutes is 3 × 10^-8 ¿m. The specific resistance of silver ink by the laser curing at the power of 5 W from 5 sec to 10 sec is 2. 38 × 10^-8 ¿m. Consequently, the curing time by using the laser is significantly smaller than that of the furnace curing.