抑制计算机信息泄漏的屏蔽技术

电磁辐射是造成计算机信息泄漏的重要因素，如何提高电磁屏蔽效能是解决电磁辐射的重要技术之一．本文中根据屏蔽技术理论分析了常用屏蔽材料的电磁性能特性，经对金属铁和锡的屏蔽效能的分析计算，选择了对电磁波具有良好反射损耗性能的金属锡薄膜和具有高吸收损耗特性的金属铁，制做了铁镀锡薄膜屏蔽机箱以进行屏蔽试验，试验在广州市国家日用电器检测所EMC认证中心的微波暗室进行．结果表明，厚度仅为0．18mm的铁镀锡膜屏蔽机箱，就能高效抑制计算机电磁辐射，有效防止计算机的信息泄漏．

Shielding Technology to Restrain Computer Information Leakage

Electromagnetic radiation is an important influenc ing factor of computer information leakage.The technology to enhance the efficiency of electromagnetic shieding is one of the important technologies to resolve the problem of electromagnetic radiation.In this paper,according to the theory of shield technology,the electromagnetic performance of common shielding materials was analyzed,and the shielding efficiencies of iron and tin were analyzed and calculated.Then,tinning film with high reflection loss and iron with high absorption loss were selected to make a ferrous case film of electrolytic tinning.The shielding test of the case was carried out in an anechoic room in the EMC authentication center of Guangzhou Testing & Inspection Institute for Household Electrical Appliance.The results show that the ferrous case with a film thickness of only 0.18 mm can effectively shield the electromagnetic radiation and avoid the imformation leakage of computers.