ScholarWorks@성균관대학교

초록

Increasing the concentration of crystalline fillers in a polymer matrix is one of the most straightforward and effective strategies to enhance the thermal conductivity and mechanical performance of thermally conductive adhesive composites. Alumina (Al2O3) is particularly compatible with epoxy resins, and various surface modification techniques have been explored to maximize its loading within such composites. This study presents a highly effective surface modification method for Al2O3 using simple agitation in an aqueous solution containing iron salt at parts-per-million (ppm) concentrations. This treatment shifts the zeta potential of the alumina fillers to a more positive value, improving their electrostatic stability and interactions with polar moieties in the uncured resin. Introducing iron-modified alumina increased the filler loading to 82.5 wt%, compared to a maximum of 80 wt% with unmodified alumina while preserving solution processability. This enhancement led to a 1.46-fold increase in thermal conductivity at 25 °C. Industrial applicability was demonstrated by producing 2 kg of modified alumina powder without generating manufacturing waste. The composite's heat dissipation performance was evaluated using a high-power LED chip array mounted on a printed circuit board (PCB), with the adhesive applied between the PCB and a heat sink. The heat sink using the modified Al2O3-based composite (82.5 wt%) reached a temperature 7.37 °C higher than that of the composite filled with unmodified Al2O3 (80 wt%), indicating significantly improved heat transfer efficiency. © 2025 The Authors

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