Theoretical and Computational Investigation of Phonon Transport and Thermal Boundary Resistance in Novel Nigerian Mineral-Based Electronic Packaging Materials

Background: Thermal management in high-power electronic packaging requires materials with high thermal conductivity and low thermal boundary resistance. Nigerian mineral resources including talc, mica, and serpentinite offer unexplored potential as low-cost electronic packaging fillers whose phonon transport properties have not been theoretically characterised. Aim: This study theoretically and computationally investigated phonon transport and thermal boundary resistance in composites incorporating Nigerian mineral-derived fillers for electronic packaging applications. Methods: First-principles lattice dynamics calculations determined phonon dispersion and group velocities in mineral crystal structures. Non-equilibrium molecular dynamics simulations computed bulk thermal conductivities and thermal boundary resistance at mineral-polymer interfaces using the Kapitza resistance formalism. Experimental polymer composite samples loaded with Nigerian talc and mica fillers were fabricated and thermal conductivity measured using the transient plane source method for model validation. Results: Talc-epoxy composites at 60 volume percent filler loading achieved thermal conductivity of 4.2 W/mK, a 17-fold improvement over neat epoxy. Molecular dynamics predictions of Kapitza resistance at talc-epoxy interfaces of 4.8x10-8 m2K/W agreed with experiment within 14%. Surface functionalisation reduced Kapitza resistance by 38%. Conclusion: Nigerian talc and mica fillers are viable high-thermal-conductivity electronic packaging materials. Surface functionalisation to minimise thermal boundary resistance is identified as the key processing optimisation. Keywords: phonon transport, thermal boundary resistance, electronic packaging, Nigerian minerals, molecular dynamics.