Thermal Interface Materials with High Thermal Conductivity and Low Young's Modulus Using a Solid-Liquid Metal...

Area of Science:

• Materials Science
• Composite Materials
• Nanotechnology

Background:

• High-performance thermal interface materials (TIMs) require both high thermal conductivity and low Young's modulus.
• A significant challenge in TIM development is the inherent trade-off between thermal and mechanical properties.
• Existing TIMs often struggle to optimize both parameters simultaneously.

Purpose of the Study:

• To develop a novel TIM strategy that overcomes the trade-off between thermal conductivity and mechanical flexibility.
• To investigate the synergistic effects of codoping solid and liquid metal fillers into polymer substrates.
• To create a composite material with enhanced thermomechanical performance.

Main Methods:

• A composite TIM was fabricated by incorporating gallium-based liquid metal and copper particles into a polymer matrix.
• The strategy involved using a high volume of liquid metal for thermal pathways and a small volume of solid fillers for enhanced conduction.
• Material properties, including thermal conductivity and Young's modulus, were systematically analyzed.

Main Results:

• A TIM with 55% liquid metal and 15% copper particles achieved a thermal conductivity of 3.94 W/(m·K) and a Young's modulus of 699 kPa.
• This codoped TIM exhibited superior thermomechanical performance compared to materials with only liquid metal or solid fillers.
• Thermal conductivity increased with liquid metal content, while Young's modulus correlated with the ratio of solid fillers to polymer.

Conclusions:

• The synergistic effect of solid and liquid metal fillers effectively addresses the classic trade-off between thermal and mechanical properties in composites.
• This codoping strategy offers a promising approach for designing advanced TIMs with tailored properties.
• The developed TIM demonstrated stable performance under thermal cycling and in practical LED applications.