Selecting the right EMI shielding material for your application can be challenging. A new Conductive Elastomer Engineering Handbook published by Parker Chomerics offers detailed technical explanations and helpful advice on choosing solutions for EMI shielding. Available as a free download in PDF format, this guide aims to help design engineers in selecting the optimum EMI gasket for the task in hand.
The handbook is an essential design companion for any engineer tasked with delivering EMI shielding solutions. As well as a thorough look at the theory behind EMI shielding, it covers corrosion resistance, with particular emphasis on design guides for corrosion control.
One of the numerous informative sections in the Conductive Elastomer Engineering Handbook focuses specifically on gasket design, where there are many areas of principal emphasis. Other chapters include seal cross-section selection, fastener requirements and designing a solid-O gasket-in-a-groove. A further section on gasket mounting techniques shows designers cost-effective choices in both materials and assembly.
The handbook also examines the performance data associated with conductive elastomers, including compression-deflection, stress relaxation, compression set and shielding effectiveness. Also covered are EMP survivability, vibration resistance, heat ageing, outgassing and lightning strike resistance.
The Conductive Elastomer Engineering Handbook includes details on the following product ranges.
CHO-SEAL® conductive elastomer materials
Once used mainly to shield critical defence and aerospace electronic systems, Parker Chomerics conductive elastomers have become the progressive choice for packaging designers of consumer, telecommunications, automotive, industrial equipment, medical devices and much more.
Conductive elastomers are reliable over the life of the equipment. The same gasket is both an EMI shield and an environmental seal. Elastomer gaskets resist compression set, accommodate low closure force, and help control airflow. They’re available in corrosion resistant and flame-resistant grades. Their aesthetic advantages are obvious.
Almost any elastomer profile can be extruded or custom-moulded with modest tooling costs for either prototypes or large orders. Parker Chomerics can also take a customer-supplied design and deliver finished parts.
Parker Chomerics offers hundreds of standard moulded and extruded products. Moulded products provide moisture/pressure sealing and EMI/EMP shielding when compressed properly in seals, flanges, bulkheads, and other assemblies. Extrusions provide similar benefits and are also readily lathe-cut into washers, spliced, bonded, kiss-cut, or die-cut to reduce installation labour and to conserve material, resulting in a cost-effective alternative to other methods of EMI shielding and environmental sealing.
CHOFORM® and ParPHorm® form-in-place EMI gasketing material
Parker Chomerics CHOFORM automated EMI gasketing system is ideal for today’s densely populated electronics packaging, particularly where intercompartmental isolation is required to separate processing and signal generating functions. CHOFORM is directly dispensed on castings, machined metal and conductive plastic housings. It provides excellent electrical contact to mating conductive surfaces including printed circuit board traces.
ParPHorm is a family of non-conductive, thermal and moisture cure, form in place, elastomeric sealing compounds. These silicone and flurosilicone materials provide environmental, fluid and dust sealing of small enclosures.
CHO-MUTE™ microwave absorber materials
Parker Chomerics CHO-MUTE elastomer based absorber materials are designed to offer a user friendly approach to the reduction of unwanted electromagnetic radiation from electronic equipment as well as minimize cavity to cavity cross coupling, and microwave cavity resonances. Comprised of a silicone elastomer matrix with ferrous filler material, these materials provide RF absorption performance over a broadband frequency range from 500 MHz to 18 GHz.
Integrated solutions for electronic housing
Parker Chomerics can supply a complete single source solution to your EMI shielding needs in plastic housing. If the device requires a display filter, Chomerics can design and supply using the latest technology. The filters can provide EMI shielding and improve view ability in any environment. The display filter may be incorporated into the housing or bezel, ready for assembly. EMI shielding gaskets can be added as an integral part of the housing using Chomerics in-house supply of all gasket technologies. If thermal management materials are needed, Chomerics can supply heat sinks with thermal interface materials integrated into the housing. Finally, non-conductive thermoplastics are available with secondary EMI coatings which may be more suited to certain applications.
To learn more about Chomerics' EMI shielding products, click here.
This blog was contributed by Melanie French, marketing communications manager, Parker Chomerics Division Europe.