Study on the Preparation and Performance of Low-Temperature Sintering and High-Thermal-Conductivity Silver Nanowire Film

This paper proposes a new silver nanoscale joining material, silver nanowire film, as an alternative joining approach for high-power and large-size chip packaging. The silver nanowire film was prepared by pressing filtration with silver nanowire that was synthesized using the polyol method. We found that the tensile strength of the film reached 3.40 MPa and the content of the silver reached up to 99.0 wt%. This paper further studies the influence of the size of silver nanowires on the performance of silver nanowire film. The experimental results show that the silver nanowire films prepared with silver nanowires with longer lengths and smaller diameters displayed better performances. The silver nanowire film with the best performance was prepared using silver nanowire with a diameter of 88 nm and a length of 29 μm. The thermal resistance of the sintered silver nanowire film that was hot-pressed at 250 °C 10 MPa was only 1.28 K∙W−1. The shear strength of the sintered joint was 56.4 MPa, and the fracture that occurred in the sintered silver nanowire film displayed a good plasticity.Keywords:electronic packaging;nano-silver;low-temperature sintering;shear strength;high thermal conductivity