하이브리드 CNT/Graphite 충진재를 이용한 실리콘 기반 방열시트의 열전도 및 내열 특성 향상 연구 = Improving the Thermal and Heat-Resistance Properties of Silicone-Based Thermally Conductive Sheets Using CNT/Graphite Hybrid Fillers

다국어 초록 (Multilingual Abstract)

This study proposes a hybrid carbon filler system composed of carbon nanotubes (CNTs) and expanded graphite (EG) to develop a lightweight and thermally conductive silicone sheet for electric vehicle (EV) electronic components. Particle size analysis confirmed the complementary size distributions of CNTs and EG-C, and EG-C/CNT = 9:1 mixture produced the most stable bimodal distribution, indicating optimal packing.
Zeta potential measurements showed that CNT incorporation improved dispersion stability in the pH 4∼6 and 9∼11 range, while SEM observations revealed that CNTs filled the voids between EG particles and strengthened the thermal conduction pathways. The resulting thermally conductive sheet exhibited significantly improved performance compared with the EG-only sheet: thermal conductivity increased from 2.1 to 3.2 W/m⋅K, heat-deflection temperature rose from 135°C to 158°C, density decreased from 3.2 to 2.4, and peel strength remained comparable. These findings demonstrate that the CNT/EG hybrid filler strategy effectively enhances thermal transport, stability, and lightweight properties, suggesting strong applicability to EV electronics and other high-power electronic systems.