EMI / RF Sealing Gaskets
EMI Gaskets are selected and used by the electrical/electronic industry to meet compliance with stipulated EMI/EMC requirements.
EMI shielding gaskets are used to provide an electrically conductive seal for electronic equipment openings and housing covers to prevent or restrict electromagnetic interference. There are many types of EMI shielding materials and solutions available to the designer
Choosing a low cost solution is also a factor. The intent of an effective gasket is not only to maximize EMI/RFI shielding, but to also reduce the number of fasteners (or screws) needed to comply with requirements.
EMI gaskets are die cut, water jet cut or compression molded from electrically conductive silicone rubber compounds.
EMI/RFI Gaskets for Connectors
Grounding of AN Series, Bendix and RF-Type Connectors to an enclosure bulkhead in a manner that will reduce the ingress or egress of EMI/RFI interference can be accomplished through the use of these connector gaskets
Connector gaskets materials can be selected to meet environmental and mechanical requirements of the package to be shielded.
These gaskets offer optimum RF grounding of connectors at minimal cost.
The elastomer embedded product is both an EMI shield and moisture seal with a minimum thickness, thus not requiring extended protrusion from surface enclosures.
Conductive Silicone Rubber for EMI Gaskets
The main advantage of EMI shielding gaskets fabricated from conductive elastomers is the combined benefit of environmental sealing over a broad temperature range and EMI shielding. This EMI gasket material is typically silicone rubber or fluorosilicone rubber with embedded silver plated aluminum particles, silver plated glass beads, silver plated copper particles, nickel-graphite particles or conductive carbon. Many of these EMI shielding materials meet the properties of Mil-G-83528B. Conductive silicone rubber materials are typically molded into sheets from .010" to .125" thick and 12" x 12" to 10" x 15" in size and then die cut to the final gasket configuration.
Compressible Conductive Nickel-Graphite Filled Silicone Gaskets
Nickel-graphite filled silicone rubber is a compressible 30 and 40 durometer conductive gasketing material. Application of conductive fabric supported acrylic adhesive provides both a conductive adhesive surface for EMI shielding integrity and dimensional stability to reduce tears during handling and assembly.
EMI Shielding Molded Gaskets
We can mold variety of conductive silicone rubber compounds . Molded gaskets allow the designer to add sealing ribs and other performance enhancing features to optimize environmental sealing and EMI shielding properties.
EMI Shield Seal Gaskets
Shield Seal Strip Gaskets are available in various material combination and sizes. The versatility of materials and sizes guarantees protection against weather conditions including extreme temperatures as well as protection against Electro Magnetic and Radio Frequency Interference leakages. The elastomers such as Neoprene , Silicone etc are available with or without an adhesive backing. The knit wire meshing is available in various wire materials with Monel and Ferrous material being the most popular. Double Shield Seal materials are available for added shielding effectiveness.
This Gasketing is used in applications such as electronic cabinets where this type of material is utilized around the doors of the cabinet to seal off stray EMI signals. The Shield Seal Strip is also used extensively to shield electronic boxes of various sizes and shapes.
EMI/RFI Shielded Rigid Frame Gasket
EMI/RFI knitted wire gasketing has been the standard shielding product and available in variety of cross sections to meet different requirements encountered in shielding applications. The choice between rectangular, round, round with fin or double round with fin depends on the enclosure or equipment to be shielded.
It consists of an aluminum extrusion with a specially designed jaw. When closed, the jaw crimps the fin of the knit wire EMI gasket to form a rigid construction with the EMI gasket held firmly in place. This extrusion, when fabricated into a frame with the corners of aluminum extrusion mitered and heliarc welded, provides a gasket assembly that can be installed with flat-head screws. This design makes retrofitting in the field a relatively easy task and at the same time provides a positive stop for controlled compression of the EMI Gasket.
This Gasket is suitable for large cabinet doors or access panels that are frequently opened. It acts like thousands of tiny spring members which are compressed and released with each opening and closing of a cabinet door or enclosure cover. The spring-lock gaskets assure long life with consistent point-to-point contact, providing high shielding effectiveness and long life. Where a moisture seal is needed , an elastomer strip can be bonded to the edge of the extrusion opposite the gasket.
An additional barrier of EMI/RFI interference can be achieved by utilizing a double-shielded construction. The double-shielded gasket is recommended for large doors where controlling the mating surface joint unevenness can be difficult and expensive.
A wide range of knit wire mesh materials is available. The standard knit wire mesh is either Monel or tin-plated ferrous. Apart from these standard materials , there are many other combination available such as aluminum, silver-plated brass, gold-plated copper, tungsten, stainless steel, silver, nickel, and other wire can be knit and fabricated into special products.