Electromagnetic interference (EMI) shielding efficiency (SE) characteristics of the ITO/Ag multilayer structure

摘要

The electromagnetic interference (EMI) shielding efficiency (SE) of multilayered thin films in which indium-tin-oxide (ITO) and Ag were deposited alternately from 3 Layer to 9 Layer on Poly Methly Methacrylate (PMMA) substrates at the room temperature using a RF sputtering. We measured optical and electrical characteristics by UV-spectrometer and 4 point probe method. The measurement of EMI shielding efficiency (SE) in the frequency ranges from 50 MHz to 1.5 GHz was performed by using ASTM D 4935-89 method. We compared the measured EMI SEs with theoretical simulation data. Our EMI SE multi-layers showed relatively low resistivities and high transmittances. In this study, we obtain good optical and electrical characteristics with a minimum transmittance of about 60% at 550 nm wavelength and sheet resistance of 2 similar to 3 Omega/sq., respectively. Measured EMI SEs were over 50 dB and similar to theoretical simulation data.