Plastic composites for electromagnetic interference shielding applications

Abstract

Abstract Research in the past eight years has established the ability of polymer composites made with sufficient electrical conductivity to be suitable as shields against electromagnetic interference (EMI). A number of conductive fillers have been used to produce such composites. These include carbon black, carbon fibers, metal fibers, metal flakes, and metal‐coated glass fibers. Each filler offers its own set of advantages and disadvantages. An important aspect of developing polymeric composites for EMI shielding applications is measuring their shielding ability in areliable, easy‐to‐use test facility. Once a reliable test has been developed, basic data relating the bulk conductivity (or surface conductivity of coatings) can be generaated. The objective of this article is to discuss the relative utility of the different types of fillers commonly used, present an analysis of the utility of different testing approaches, and show data correlating volume resistivity with shielding effectiveness.