Microwave Journal: Metal Clad Fibers for Weight-Sensitive Applications
ARACON® metal clad yarns and EMI shielding braids have been supporting weight reduction in high-reliability applications for more than two decades. Micro-Coax manufactures ARACON using aramid fibers and a special sequence of chemical processes to deposit a metalized coating around every individual microfilament. The result is a strong, highly flexible, heat resistant alternative to conventional metal wires. Recent improvements in the manufacturing process allow a cost to implement of under $300 per lb, breaking an economic threshold that will enable use in a much wider range of applications, including commercial aircraft, drones and smart fabrics.
Switching conventional wire over to ARACON fibers offers dramatic weight savings — as much as 80 percent less than nickel-plated copper shields. Three different yarn sizes allow for a wide variety of multi-strand, braided and woven form factors. In its braided form, the transfer impedance approaches 120 mΩ/m at 1 GHz. This, combined with smaller braid apertures of the microfilaments, allows for shielding effectiveness of more than 40 dB, verified up to 18 GHz.
Connection or termination of the fibers can be addressed mechanically (i.e., clamping) or by soldering. The silver-plated version of the product can easily be soldered by conventional techniques, without the use of active flux. The material is also resistant to uncontrolled soldering-wicking, which further improves the reliability of the connections. These conventional termination methods allow the product to be incorporated in host wire and cabling applications, such as quad-ax, coaxial or other shielded constructions.