The configuration of thin film polycarbonate (PC) is formulated, aiming for a financially efficient approach of the solvent casting method by grafting waste fly ash cenosphere (FAC) encapsulated with tetraethoxysilane (TEOS) as a grafting agent. The research study emphasized on the routine practice of controlled thermal dissipative electronic widgets by a systematic characterization analysis. FTIR exemplifies the surface adherence characteristics of the GFAC (Grafted Fly Ash Cenosphere) over PC, by confirming the efficient grafting between silane and FAC at 2950 cm⁻¹ due to the flexible vibrations by the –OH group. The PC–FAC composite showed the characteristic triplet signature peaks of PC at 1152, 1188 and 1227 cm⁻¹. Following the hierarchy, the morphological study analyzes the surface molecular interaction between the PC/GFAC and their electronic properties by FESEM. AFM confers the topographical study of pristine PC, which measures the surface roughness of pristine PC as 4.5 nm which mitigates to 0.7 nm for the PC/GFAC and justifies the homogenous dispersion of GFAC in PC, thus directing the consequential study of TGA. It examines controlled surface thermal conduction and authenticates the noble thermal stability of the PC/GFAC with a char yield of 36% (approximately more than twice that of pristine PC) at 800 °C by TGA. The PC/GFAC affirms a 70 °C lag in the onset of thermal degradation, at 430 °C, as compared with pristine PC, which starts to decompose at 360 °C. Thus, the silane grafted nano composites of PC expands the operable temperature range for the electronic elemental properties usage. The present investigation procures attention on the thermal characteristics of the PC/GFAC, illustrated by the conduction modeling parameter across the spherical wall of the cenosphere and the interfacial heat transfer for the PC/GFAC composite, pertaining to a worthwhile and serviceable thermal management praxis.