# Water vapor assisted sintering of silver nanoparticle inks for printed electronics

## TL;DR

This paper demonstrates a water vapor-assisted sintering method for silver nanoparticle inks that achieves high conductivity at temperatures below 120°C, enabling printed electronics on plastic substrates.

## Contribution

It introduces a novel water vapor-assisted sintering process that significantly reduces resistivity at low temperatures, expanding the potential for flexible printed electronics.

## Key findings

- Resistivity decreases significantly with water vapor sintering.
- Effective sintering achieved at temperatures as low as 80°C.
- Water vapor enhances nanoparticle neck formation and conductivity.

## Abstract

In printed electronics, conductive traces are often produced by printing inks of silver nanoparticles dispersed in solvents. A sintering process is usually needed to make the printed inks conductive by removing the organic dispersants and allowing metal-to-metal contacts among nanoparticles for atomic diffusion and neck formation. It has been challenging to sinter silver nanoparticle inks in a thermal oven at a temperature < 150 C to avoid thermal damage to the plastic substrate while achieving desired conductivity. This work presents a simple yet effective way to sinter a silver nanoparticle ink below 120 C (even at 80 C) by exposing the printed ink to water vapor in the oven. The results consistently show a significant reduction of line resistivity for the samples sintered in a moist oven compared to those sintered in a dry oven. Hence, solvent vapor-assisted sintering of metal nanoparticle inks can become an enabling approach to broaden product range of printed electronics.

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Source: https://tomesphere.com/paper/1906.10646