New Catalog Describes Benefits of Canted Coil Springs for EMI/RFI Shielding

A new technical catalog published by Bal Seal Engineering, Inc. provides engineers and designers with detailed information about how canted coil springs can be used to address electromagnetic interference/radio-frequency interference (EMI/RFI) shielding challenges. The 10-page catalog, titled “Bal Spring™ canted coil spring: Solutions for EMI/RFI Applications,” describes how the company’s compact, precision-engineered spring protects sensitive electronics from the harmful effects of EMI/RFI, particularly in high-frequency, small-package applications.

The catalog presents data on the spring’s EMI/RFI shielding properties, including transfer impedance and shielding effectiveness, as well as graphics illustrating attenuation vs. frequency at 1–10 GHz and 100 MHz–1 GHz. Summary testing data show that the spring exhibits much lower transfer impedance than finger stock, helical flat springs, or wire mesh over elastomer technologies.

Shielding performance data in the catalog were compiled from transfer impedance (SAE ARP 1705) measurements taken from over 150 different configurations. Bar graphs present data in terms of specific parameters, including materials and platings, groove types, and forces. A force deflection chart depicts the spring’s mechanical properties, examples of typical groove configurations illustrate optimized spring performance in various user geometries, and the most common assembly orientations are shown along with typical examples.

Bal Spring canted coil springs have been tested and proven to provide effective shielding in the packaging of electronics enclosures. As interface components, the springs offer a simple, economical design that greatly reduces radiated and conducted interference. Unlike filled elastomers, the springs also resist compression set and offer improved durability and reliability.

Available in a broad range of coil heights, wire materials, and plating types, the Bal Spring canted coil spring maintains a nearly constant force over a broad compression range, compensating for angular misalignment, surface irregularities, and even temperature changes without significant deviation from its initial force. Each coil works independently, maintaining contact with the mating surface and ensuring maximum conductivity. The versatile component’s locking, latching, and holding properties also allow designers to meet very specific insertion and breakaway force requirements.

The new catalog can be downloaded free of charge from the company’s online technical library at www.balseal.com/technical-library. Requests for free printed copies can be e-mailed to sales@balseal.com.