Solder paste for highly dissipative power electronic assemblies

This work highlights the interest of silver oxalates precipitated in hydro-alcoholic media as new soldering material. The silver-oxalate-based solder can be decomposed starting from temperatures as low as 90°C and leads to the formation of temporary nanometric grains of metallic silver having a high propensity for sintering. The final material is a porous silver network that can be used as high thermal conductivity electronic interface material with performance around 100 W/m.K for samples made at moderate temperature (<;300°C) and low pressure (<;0.5 MPa). The micrometric size of the oxalate powders reinforces this interest because safety procedures induced by nanoparticles handling are not required in our case, in contrast to existing soldering products made of silver nanoparticles.