Optimized Bimodal Silver Particle Sintering for High Thermal Conductivity Die-Attach Layers

A bimodal silver system can achieve higher effective thermal conductivity (ETC) than a mono-system for electronic packaging. However, the effect of micron- and submicron-particle compositions on the microstructure and ETC of sintered Ag is unclear. In this study, Ag films with varying particle compositions were fabricated by pulsed laser deposition. The results indicate that the sintered bimodal Ag film with 76 vol% submicron-particles possesses the highest ETC (260 W m- 1 K-1). This enhancement is attributed to the decreased porosity, increased pore circularity and pore distribution uniformity. This particle composition modulation strategy can provide a guideline for developing high-performance die-attach materials for electronic packaging.