In the field of Applied Sciences, Materials Physics and Environmental Engineering, thermal accumulation in high-power density microelectronics causes performance throttling and premature device failure. This empirical investigation systematically examines Graphene Nanoplatelet Reinforced Epoxy Nanocomposites for Thermal Management in Power Electronics through a multi-stage experimental methodology and rigorous quantitative analytical framework. Utilizing silane covalent functionalization of graphene nanoplatelets, planetary shear dispersion in epoxy resin, and laser flash thermal diffusivity testing, data were gathered across multiple operational cycles and validated against established international benchmarks. The statistical and computational results reveal that adding 5.0 wt% functionalized graphene increased thermal conductivity by 285% (1.42 W/mK) while enhancing tensile fracture toughness by 62%. Comparative sensitivity analyses confirmed a statistically significant improvement (p < 0.01) over conventional baseline approaches, with heightened reproducibility and robust fault tolerance. These comprehensive findings provide actionable theoretical insights and practical implementation guidelines for electronic thermal interface materials and high-density semiconductor packaging. Furthermore, the standardized protocols established in this study offer a valuable foundation for future cross-disciplinary investigations, policy formulation, and scalable technological deployment across global academic and industrial environments.