Robert McKeown Co. offers electrically conductive elastomers to provide EMI/RFI shielding, as well as protection from environmental factors like dust and water. These EMI shielding gaskets add superior shielding for a range of electronic applications including aerospace, telecommunications, automotive, medical, and industrial equipment.

Caused by various external disruptive forces, electromagnetic interference (EMI) poses great risks to electronics devices, equipment, and systems of all kinds. Affecting electrical circuits through electromagnetic induction, electrostatic coupling, or conduction disturbance, EMI can result in data loss, increased error rate, total system failure, and even death.

Understanding EMI

EMI is especially dangerous in critical and sensitive applications; mass transit systems, industrial touch screens, navigation and vehicular control systems, and medical, military, and aerospace electronics are all susceptible to EMI. And depending on the specific type of electronic system, the results of EMI can be catastrophic. In medical or mass transit electronic applications, for example, EMI is not only costly and time-consuming to remedy, it’s also life-threatening. In these situations, electronics must be capable of reliable, long-lasting performance to ensure the safety and well-being of all individuals.

Having a basic understanding of EMI — specifically, the electromagnetic fields within the radio frequency spectrum that will damage your system — is key to successful, uninterrupted operations. To prevent the risks mentioned above, it’s critical to work with high-quality conductive elastomers and other EMI shielding components when designing electronic devices. EMI shielding gaskets, for instance, must be able to provide reliable sealing and protection against electromagnetic interference.

EMI Shielding Gasket Features

EMI gasket materials were once made from aluminum, copper, and steel sheets and shaped to fit electronic enclosures. However, these thin metal sheets would deform under sealing pressure, resulting in circuit leaks. EMI shielding has since evolved and is now fabricated from flexible metal screens, wires, and foams, which are not subject to the risk of deforming. One of the most effective materials for EMI shielding is a conductive elastomer, such as particle-filled silicone, which combines the electrical properties of metals with the material properties of silicone rubber.

Serving as a highly reliable sealing and insulation material, particle-filled silicone is increasingly becoming the go-to material choice for shielding gasket manufacturers. Because particles can be adapted for various durometers, they’re able to easily accommodate the specific level of hardness required by the specific gasket type. Also, these newer shielding gasket materials contain adequate amounts of metal filler to guarantee effective shielding and electrical conductivity, allowing for highly reliable, cost-effective fabrications.

Unlike the original EMI shielding gaskets, particle-filled silicone EMI gaskets are not at risk of stretching or becoming deformed, ensuring a longer lifespan. This, in turn, allows for lower maintenance costs, since replacements or repairs are needed less frequently. Tear-resistant options are also available for manufacturers working with thin-walled EMI gaskets, while adhesive-backing options allow for very simple installation.

Conductive Foam Shielding Gaskets

Conductive foam — made of polyurethane plated with copper and nickel — is also an ideal material choice for shielding gaskets. Able to withstand harsh, demanding applications, conductive foam offers great cost-efficiency and easy manufacturability. Allowing for the creation of conductive EMI gaskets — which are highly effective for shielding applications since they offer cross-section conductivity — this foam strengthens the efficacy of shielding without sacrificing any functionality.

In addition to a low compression set, allowing for long-lasting performance, conductive foam also has low flammability characteristics and high workability, and is easy to cut and slit. This versatile foam is frequently used in noise filter cores, shielded rooms, and mobile phones.

Fabric Over Foam Gaskets

At Robert McKeown Company, Inc. (RMC), we offer several lines of Parker Chomerics products, including their SOFT-SHIELD® fabric over foam (fof) EMI shielding gaskets — a low-cost, high-performance solution well-suited for commercial electronic systems.

An ideal alternative to beryllium copper or stainless steel fingerstock EMI gaskets, fabric over foam products require fewer fasteners thanks to their very low closure forces and allow for simple installation without sacrificing shielding ability. Also, cut-to-length strips of fabric over foam gaskets self-terminate, eliminating the risk of jagged edges that can cause damage and enhancing overall application reliability.

The urethane foam core has excellent compressibility, making these EMI gaskets well-suited for thin-walled plastic enclosures. Extremely versatile, fabric over foam gaskets are often used in medical and general industrial applications.

Learn More

For more information on thermal management products or to discuss how Chomerics EMI gaskets can help protect your electronics equipment, contact the team at Robert McKeown today.