Thermal and electrical percolation transport behavior in composite materials with oriented binary fillers

In IC packaging, thermal interface materials must exhibit high thermal conductivity and electrical resistivity to prevent short circuits, enhance reliability, and ensure safety in high-voltage applications. We proposed the thermal-percolation electrical-resistive thermal interface material (TP-ER TIM) incorporating binary fillers of both insulating and metallic nanowires with an orientation in the insulating polymer matrix. High thermal conductivity can be achieved through thermal percolation, while electrical non-conductive is preserved by carefully controlling the electrical percolation threshold through metallic nanowires orientation. The electrical conductivity of the composite can be further regulated by adjusting the orientation and aspect ratio of the metallic fillers. A thermal conductivity of 10 Wm^-1K^-1 is achieved, with electrical non-conductive behavior preserved. This approach offers a pathway to realizing ”thermal-percolation electrical-resistive” in hybrid TIMs, providing a strategic framework for designing high-performance TIMs.