In-situ alleviation of surface modifier passivation effects in silver nanoparticle laser sintering process

The surface modifiers passivation effects on silver nanoparticles limit the conductivity of silver nanoparticle ink sintered circuit. In this work, the synchronicity of surface modifiers removal and silver particle coalescence, and energy consumption by surface modifiers removal were analyzed. By pre-adding 0.015 wt% destabilizing agents (Na⁺Cl⁻) into the silver ink, sintering behaviors and energy transfer mode were changed. Reduction ratios in resistivity of 25.7 % were achieved without changing laser parameters by the proposed in-situ strategy. A minimum resistivity of 5.06 μΩ·cm was achieved. Pre-adding Cl⁻ advanced the startup time of surface modifiers desorption and prevented the surface modifiers negative effects on sintering neck growth. Moreover, the surface modifiers desorption turned from energy consumer to energy provider, allowing more energy for silver particle coalescence. This work would shed light on improving silver ink laser sintering conductivity and enhancing the performance of printed electronics.