Influencing factors on the Electromagnetic Shielding Property of Coated Steel Sheets

Abstract

When coated steel sheets are used as a chassis for electrical equipment, electromagnetic waves are thought to propagate through the space formed by a lid and a flange. This study was designed to clarify characteristics of coated steel sheets that can affect electromagnetic shielding properties at locations where steel sheets overlap. The influence of resin coating weights of the steel sheets on the electromagnetic shielding property was examined. This study also examined the influence of steel sheet surface profiles on the electromagnetic shielding property. For this study, resin was coated on the steel sheets which have the same interval between peaks of a waviness curve, the arithmetic average roughness Ra and the different interval between peaks of a roughness curve（PPI）. For greater resin coating weights on the steel sheets, the electromagnetic shielding property was lower at the same steel sheet surface profile. However, with higher PPI on the steel sheet surface, the electromagnetic shielding property was enhanced at the same coating weight. The electromagnetic shielding mechanism of the coated steel sheets was discussed based on these results.