Absorption-Dominant EMI Shielding Materials Based on Aluminum Foil-Supported Thermotropic Liquid Crystalline Polyester/Carbonyl Iron Powder Composites
발표자
최형호 (충남대학교 유기응용재료공학과)
연구책임자
정영규 (충남대학교 유기응용재료공학과)
초록
내용
This study shows a hybrid electromagnetic interference (EMI) shielding material composed of aluminum (Al) foil and a thermotropic liquid crystalline polyester/carbonyl iron powder (TLCP/CIP) composite. Pure Al foil shows ~80% reflection, 20% absorption, and total shielding effectiveness (SET) of ~40 dB in the X-band. Adding a 960 μm-thick TLCP/CIP layer lowers reflection to 25%, increases absorption to 75%, and SET to ~50 dB. These enhancements arise from dielectric-magnetic synergy and destructive interference at the air–TLCP/CIP and TLCP/CIP–Al foil interfaces. The TLCP/CIP layer causes multiple internal reflections, enabling coherent cancellation and energy conversion to heat. This asymmetric design reduces secondary electromagnetic pollution and achieves absorption-dominant shielding, increasing SET by ~25% over pure Al foil. Experimental results align with theory, showing thickness engineering converts metal shields into high-performance X-band EMI absorbers.