Electrical/thermal conductivities of low-temperature sintered/Ag-decorated epoxy microspheres

Abstract

The last decades composite production has benefited from additive manufacturing rendering production of special parts feasible and economical. Energy and time-consuming processes have improved significantly since the implementation of low temperature sintering methods. In this work, we prepare sub-micron powders in an attempt to produce conductive composites via compression sintering at a low overall production cost. Epoxy microspheres of glassy and rubbery type are synthesized in a controlled manner to inherit certain properties, and then decorated via a controlled deposition process of silver nanoparticles to form fine powders. The resulting fine powders are compressed at room temperature conditions to consolidate and hopefully sinter at post-cure. We study the structure-property relationship of the powder structure and the effect in the conductive properties that arise after consolidation. Remarkably, the compressed powders achieved DC conductivity with extremely low silver nanoparticle content (7.7 wt %, approx. 0.9 vol %) as compared with other literature reports and a promising increase in thermal diffusivity of about 18 % with just 4.2 wt % of silver nanoparticles.