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Electronic equipment is generally enclosed in plastic housings, which consist of separate parts most commonly manufactured by injection moulding. When these parts are assembled, inevitably there are narrow gaps where the joining faces meet. Gaskets are normally used to prevent particles and moisture entering the enclosure. When used for electronic devices, however they have an additional and vital role to play. They must form an integral part of the electrically conductive shielding shell that encompasses the working components of the device. Although many types of gasket can be used, such as woven wire mesh, the use of gaskets moulded in elastomeric products, in particular silicones resins, is dominant in this application. A number of materials can be used as additives to these resins, to provide the required degree of electrical conductivity, as well as retaining other properties essential to the performance of the gasket, such as hardness, tensile strength and compressibility. These include: Nickel-Coated Graphite For general commercial applications, nickel-coated graphite has become one of the most popular additives for conductive elastomeric materials. It sits mid-way between other fillers in terms of attenuation performance and price. There are two grades in commercial use 60% Nickel and 75% nickel. Go to nickel-coated graphite page → Nickel Powders Although nickel powders have been used in this industry, nickel-coated graphite is generally preferred because of its superior performance. Silver and Silver-Coated Products Due to price considerations, these are only normally used where the highest performance is required such as in the aviation and aerospace industries. There is, however, a wide range of silver-coated particles with both metallic and non-metallic substrates available. Go to silver-coated products page → Graphite particles The level of performance of uncoated graphite particles is not generally adequate for modern shielding requirements. For more information on electrically conductive gaskets, please contact us. |
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Electrically Conductive Gaskets
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