In situ Raman spectroscopy monitoring of interface aging in aluminum-filled polydimethylsiloxane composites

The increasing power density of chips poses a significant challenge in the form of material aging for aluminum-filled polydimethylsiloxane (Al/PDMS) composites, which are widely used in thermal interface materials. Despite the growing importance of this issue, the specific mechanisms behind the interfacial aging process remain elusive, hindering a comprehensive grasp of the aging dynamics in these composites. In our research, we have developed an in-situ Raman aging monitoring system that leverages the non-contact and high-resolution capabilities of Raman spectroscopy to study the interface aging process. Our findings indicate a notable decrease in the intensity of the Raman peak as further cross-linking of the molecules during aging, with the most pronounced decline occurring at the interface between aluminum and PDMS. This insight could potentially elucidate why the interface in composite materials is frequently the site of failure during aging. Our study offers a versatile methodology for investigating the interfacial aging of polymer composites, contributing to a broader understanding of the interface behavior in composite materials at the molecular level.