The purpose of this paper is to present a novel nanostructured polymer-metal composite film providing continuous all-metal thermally conductive pathways, intended to meet future performance requirements on thermal interface materials (TIMs) in microelectronics packaging applications.
Porous polymer structures with a thickness of approximately 100mm were manufactured using electrospinning technology. Pressure-assisted infiltration of low-melting temperature alloy into the porous polymeric carrier resulted in the final composite film. Thermal performance was evaluated using an accurate and improved implementation of the ASTM D5470 standard in combination with an Instron 5548 MicroTester. Finally, a brief comparative study using three current state-of-the-art commercial TIMs were carried out for reference purposes.
Composite films with continuous all-metal thermally conductive pathways from surface to surface were successfully fabricated. Thermal resistances down to 8.5 Kmm2
/W at 70mm bond-line thickness were observed, corresponding to an effective thermal conductivity of 8W/mK at moderate assembly pressures (200-800 kPa), more than twice the effective thermal conductivity of the commercial reference materials evaluated.
A unique high-performance nanostructured polymer-metal composite film for TIM applications with the potential to meet the microelectronics industry’s future demands on thermal performance and cost efficiency is presented.
Micrograph of the approximately 300 nm thin metal coating deposited on the fiber bodies