금속메쉬 / 섬유강화 복합재료의 전자파 차폐효과에 관한 연구

Abstract

Recently, usage of electronic devices, including computers, electronic ovens, printers, cellular phones, etc, have been rapidly increased in our daily life and industries. However, an electromagnetic interference has been generated by the electronic devices. Hence, an interest in electromagnetic interference shielding materials has been continuously increased in the electronic industries. Metals, such as aluminiums, nickles, coppers, etc, has been widely known as an excellent electromagnetic interference shielding material. However, The metals has a disadvantageous characteristics including a heavy weight, an expensive cost and a corrosion. The goal of this thesis is to investigate into the influence of material composition and design on electromagnetic interference shielding characteristics. Several fiber reinforced composite specimens consisting of coarse copper meshes, fine copper meshes, aluminum films, glass fibers and stainless fibers were manufactured to perform the electromagnetic interference shielding experiments. In order to soak the specimen in electromagnetic fields, flanged coaxial transmission line sample holder was fabricated according to ASTM D 4935-89. Electromagnetic shielding efficiency (EMSE) was measured to quantitatively examine the electromagnetic shielding characteristics of designed specimens. The EMSE was measured in the frequency range of 300 - 1,500 MHz. The results of electromagnetic interference shielding experiments showed that maximum EMSE values of specimens with coarse and fine copper meshes were 60 dB at a frequency of 600 MHz and 70 dB at a frequency of 1,500 MHz, respectively. The maximum EMSE value of sandwich type specimen, which consists of both two skin sheet with stainless fibers and core with glass fibers, was 80 dB at a frequency of 1,500 MHz. From these results, it was noted that the sandwich type specimen consisting of skin sheets with stainless fibers and core with glass fibers has an excellent electromagnetic interference shielding characteristics in a high frequency range of electromagnetic wave. In addition, tensile strengths of the designed specimens were obtained through tensile tests.