Optimizing Silver Paste Conductivity with Controlled Convection for Nanowrinkle Growth

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Conductive silver paste is vital for interconnecting electrodes in electronics and solar cells.
• The performance of silver paste depends heavily on silver powder preparation and sintering.
• Optimizing silver paste requires understanding powder morphology and its impact on conductivity.

Purpose of the Study:

• To investigate the influence of fluid dynamics on silver powder preparation.
• To elucidate the formation mechanism of wrinkled silver powder using advanced characterization and simulation.
• To evaluate the performance enhancement of silver paste utilizing wrinkled silver powder.

Main Methods:

• Fluid dynamics analysis during silver powder preparation.
• X-ray diffractometer (XRD) characterization.
• Molecular dynamics (MD) simulations.
• Mixing and sintering experiments with wrinkled and flake silver powders.

Main Results:

• A novel wrinkled silver powder morphology was formed, replacing traditional smooth spherical powders.
• The wrinkled morphology facilitated line and surface contact, enhancing conductivity compared to point contact.
• Improved electrical conductivity and sintering morphology were achieved in silver paste containing wrinkled powder.
• Significantly reduced silver content (66.7%) was sufficient to achieve high conductivity (9.23 ± 0.68 × 10^-6 Ω cm) at 250 °C for 45 min.

Conclusions:

• Fluid dynamics control is key to achieving desired silver powder morphology.
• Wrinkled silver powder offers superior contact and conductivity in silver paste formulations.
• This research presents a new method for morphology control of submicrometer silver powder.
• The findings are significant for developing advanced low-temperature silver paste for N-type batteries.