하이브리드 도전성 필러를 이용한 섬유강화 복합재료의 전자파 차폐 효과에 관한 연구

Abstract

Recently, usage of electronic devices, such as computers, electronic ovens, printers, cellular phones etc, have been rapidly increased in our daily life as well as electronic industries. However, detrimental effect of the electromagnetic interference, generated by the electronic devices, has to be tackled for the safety of users. Hence, an interest in electromagnetic interference shielding materials has been continuously increased in the electronic industries. Metals, such as aluminiums, nickles, coppers, have been widely known as an excellent electromagnetic interference shielding material. But, metals have disadvantageous characteristics including heavy weight, expensive cost and corrosion. The goal of this thesis is to investigate the influence of material composition on electromagnetic interference shielding characteristics. In order to achieve the goal, carbon black composites (PCb1∼PCb6) and carbon fiber reinforced composites (CFRP/CFRPS/CC/CCS/AC/ACS) are prepared to see their electromagnetic interference shielding effect. For the test, the range of frequency between 300MHz ~ 1.5GHz is applied using ASTM D4935-89 standard method. The shielding effectiveness of the specimen was measured using the Anritsu 37369C vector network analyzer system and flanged coaxial transmission line measurement jig. It is found that AC and ACS specimens show higher shielding efficiency than the other specimens at whole frequency range applied. In particular, at around 1.5GHz, the efficiency is more than 90dB, which is quite effective. In addition, PCb specimen appears to be the more conductive carbon black content, the higher shielding efficiency. But it also causes to increase the viscosity, resulting in difficulty of specimen fabrication. Through this study, it is confirmed that fiber-reinforced composites as well as carbon black coposites using conductive filler show various, but distinguished trend of efficiency depending on the characteristics of the materials used.