An Integrated Approach to Design and Develop High-Performance Polymer-Composite Thermal Interface Material.

Area of Science:

• Materials Science
• Computational Modeling
• Polymer Composites

Background:

• Developing effective thermal interface materials (TIMs) is crucial for managing heat in electronic devices.
• Current design strategies often struggle with high filler concentrations, limiting thermal conductivity.
• Optimizing filler attributes and filler-matrix interactions is key to enhancing TIM performance.

Purpose of the Study:

• To develop a computational framework for designing high-performance polymer TIMs.
• To enable the design of materials with non-dilute filler concentrations (~60 vol%).
• To tailor effective thermal conductivity by manipulating filler characteristics and interfaces.

Main Methods:

• Utilized a novel differential effective medium approximation and mean-field homogenization.
• Considered various polymers (HDPE, TPU, PP) and ceramic fillers (Al2O3, AlN).
• Validated predictions against experimental data for melt-mixed and compression-molded composites.

Main Results:

• Achieved high thermal conductivity (4-5 W m⁻¹ K⁻¹) in HDPE and TPU composites with ~60 vol% ceramic fillers.
• Demonstrated excellent agreement between predicted and measured thermal conductivity and coefficient of thermal expansion.
• Validated that filler alignment and aspect ratio significantly enhance heat conduction networks.

Conclusions:

• The computational framework effectively designs high-performance polymer TIMs at non-dilute filler loadings.
• Material properties like thermal conductivity can be precisely tailored by controlling filler attributes.
• Optimizing filler orientation and shape is critical for achieving ultra-high thermal conductivity in composites.