Three-dimensional nano-structure investigation on a thermo- and electrical conductive adhesive via X-ray imaging

Nowadays, advancements in adhesion of huge amount of electronic components have evolved from using traditional soldering to conductive adhesives, notably silver-based ones, offering cost efficiency, health safety, and superior thermal conductivity, which is crucial for the increasing computational speeds and thermal management in microelectronics. Hence it is imperative to undertake a comprehensive analysis of these materials. In this work, the inner structure of a silver adhesive applied in splicing electronic components was investigated to reveal the mechanisms and factors of its thermal and electrical conductance. Transmission X-ray microscopy (TXM) with nanoscale resolution (for three-dimensional (3D) imaging) was used to characterize the samples. The results demonstrate that the regularly concentrated silver particles, mostly with a length less than 1 μm and with a volume less than 1 μm 3 with flaky shape, are arranged to form the continuum conductive paths inside the matrix materials. The thermal and electrical conductance of this adhesive have been studied and analyzed, and proven to be superior along the surface-normal direction. The nearly-perpendicular grain orientation of the inner silver particles and the parallel orientation of the particles next to the adhesive surfaces both act to optimize the conductance of the heat and electrons of this materials. Nano-structure of the silver conductive adhesive