New Scientist reports that by using a motor to unwind a roll of sticky tape, researcher Seth Putterman and colleagues from the University of California, Los Angeles recorded the electromagnetic emissions produced by ripping the tape from its roll at 3 centimeters per second. This action generated X-ray bursts of 15 kiloelectronvolts – each lasting one-billionth of a second, and … [Read more...]
Combo Strips Forestall Both EMI and Environmental Problems
The TechMesh© Combo Strip and Gasket from Leader Tech have been crafted for use in applications requiring EMI/RFI shielding and environmental sealing. These materials are comprised of monel or tin-plated, copper-clad steel knitted wire mesh that are bonded to neoprene sponge, silicon sponge, or or silicon solid elastomer strips. The wire mesh provides shielding performance up … [Read more...]
Conductive Materials Available in a Wide Variety of Formulations
E-Fill™ from Sulzer Metco is an aluminum compatible nickel graphite conductive filler that offers advanced corrosion resistance and stability in harsh environments. It is especially well suited to applications involving coated flanges. The angular shape of E-Fill™ coupled with a proprietary hard nickel coating gives gaskets the necessary “bite” needed to ensure optimal … [Read more...]
Sheet Solutions Are Designed With High Permeability and High Temperature Resistance
The WX Series from ARC Technologies provides superior EMI absorption by combining proprietary, high-performance magnetic materials into a flexible, resilient elastomer. Precisely blending refined fillers in exacting ratios with polymer substrate materials creates a thin, flexible EMI-absorbing sheet that will attenuate from 100 MHz to 3 GHz. Surface resistance is >3 MΩ. WS … [Read more...]
Conductive Tabs Provide Low Impedance
Conductive grounding from Chomerics provide EMI protection by establishing low impedance ground paths between electrically conductive elements in a chassis or component. These stabs forestall interference from the surface currents that “excite” metal components and thus create “phantom” fields. The tabs can be used to provide the required grounding paths economically as … [Read more...]
Understanding Shielding Effectiveness of Materials and Measurements in the Near-Field and Far-Field
When we treat the shielding effectiveness measurement with a uniform field, the results are similar for both near and far fields. Kermit O. Phipps and Philip F. Keebler EPRI EMC Laboratory, Knoxville, TN, USA INTRODUCTION Traditionally Schelkunoff’s shielding effectiveness equation is used universally in teaching and practice throughout the EMC community as a whole. In this … [Read more...]
Shielding Effectiveness of Gaskets, Composites and Shields
There is an ever-increasing demand for lighter, stronger, easy-to-manufacture and cost-effective shielding solutions. Jack Prawica and Jereme Irwin DLS Electronic Systems, Inc., Wheeling, IL, USA As we move into the 21st century, there is a demand for stronger, lighter, less expensive, and environmentally friendly, RoHS-compliant* conductive materials. Many industry insiders … [Read more...]
Introduction to Composite Electromagnetic Noise Absorber Technology
Thin and flexible materials can provide simple and innovative solutions for hardware engineers Jung-Ju Suh, Ph.D. Electrical Markets Division, 3M Korea; Seoul, South Korea INTRODUCTION Electromagnetic interference issues can arise anywhere in electronic equipment with unpredictable and troublesome effects. These issues challenge hardware design engineers, and the … [Read more...]
Stability of Nickel-Graphite Conductive Filler in Silicone Elastomer for EMI Shielding Applications
How does aging affect the shielding effectiveness of a gasket? Brian W. Callen, Ph.D. and Claudia E. Johnston Sulzer Metco (Canada) Inc., Fort Saskatchewan, Alberta, Canada Nickel graphite conductive fillers have been replacing conventional silver-based fillers in EMI shielding gasket materials. Filled elastomer shielding gaskets include extrusions, molded shapes, die cut … [Read more...]
Conductive Painting of Plastics: Delivering Value and Flexibility
Portable electronics manufacturers must evaluate coating processes based on consistency, repeatability, economy, and the availability of applicators worldwide. Roy Bjorlin, William Chen, Neil Browes and Darren Evans Spraylat Corporation Pelham, NY, USA Conductive paint technology has grown steadily in preference when conductive coatings are required on injection-molded … [Read more...]
