RFI and EMI - Contacts, Fingerstock and Gaskets

Radio frequency interference (RFI) and electromagnetic interference (EMI) are both electromagnetic phenomenon that often have detrimental effects on electronic operations. In order to reduce the amount of interference caused from either of these sources, it is necessary to properly insulate and isolate sensitive components from both signal sources. Contacts, fingerstock, and gaskets are critical components to minimize the interference and its effects.

Contacts

Contacts are conductive antennas that are designed to transfer electrical power or signals in a reliable and controlled manner. Contact materials are usually manufactured from metals, such as copper, nickel, brass, and silver. Non-metal contact materials, such as graphite, carbon, and plastic, are also available. These contact materials may be used to form individual contacts, which can then be pressed or soldered to create an electrical connection. Contacts can also be formed from several discrete contact elements that are joined together to form a single contact, providing higher current capacity than individual elements.

Contacts are used in a number of EMI and RFI applications. For RFI, contacts are used to ensure a secure connection between two components or connectors, reducing the potential path for interference. In EMI applications, contacts are used to reduce contact arcing that can cause significant levels of interference. Furthermore, the higher correlation between the contact material, contact surface area, current, and voltage increase the effectiveness of the contacts in protecting from EMI and RFI interference.

Fingerstock

Fingerstock is a type of insulation material used to prevent the transmission of potentially damaging electrical signals. It is made from a range of materials including, fabric, veneer, cork, vinyl, leather, mylar, and various combinations of these materials. Fingerstock is designed to provide both insulation and grounding for electronic components and systems. Its insulating properties help prevent both crosstalk and noise from interfering with the signal or power transfer. Its conductive properties restrict or ground unwanted electrical signals.

Fingerstock is used in a variety of EMI and RFI applications. It can be used to shield cables and connectors, absorb unwanted noise, and dampen shock and vibration from entering a sensitive component. It is especially effective in preventing EMI leakage from the perimeter of a multi-layer printed circuit board. This helps in improving the performance of a system, especially in regards to signal integrity and timing.

Gaskets

Gaskets, or more correctly known as shielding gaskets, are small pieces of metal that are used to shield electronic devices from environmental electromagnetic interference, as well as from internally generated EMI. The gaskets are essentially thin metal sheets with an adhesive backing that can be easily applied to electronic components, printed circuit boards, connectors, and housings. These gaskets work in two ways: either they reduce the amount of interference that is conducted from one part to another, or they completely block the transmission of EMI between components.

Gaskets are an essential component for reducing EMI and RFI interference. As most electronic devices contain components that generate and receive considerable amounts of electrical signals, gaskets are used to provide an effective barrier from outside sources that could interfere with these signals. Gaskets effectively minimize the transfer of interference, while still allowing the intended signals to be received.

Conclusion

Contacts, fingerstock, and gaskets are all important components to consider when mitigating EMI and RFI interference. Each component has specific applications and should be appropriately chosen and applied for optimal performance. By using these components, one can ensure that their system is adequately shielded and insulated from potentially damaging interference.