In late 2012 Rogers Corporation announced that their thin grade of nickel graphite filled gel-base silicone would be discontinued. EC-2040 was a 40 durometer conductive silicone rubber used for EMI gasketing, offered in .020″ and .031″ thicknesses. Stockwell Elastomerics regularly applied 3M 9713 electrically conductive adhesive to EC-2040.

EMI Silicone GasketSince EC-2040 was discontinued, Stockwell Elastomerics worked with SSP, a specialty silicone compounder, to offer a suitable replacement product. SSP has compounded SSP502-40, a nickel graphite filled gum-base silicone, with superior electrical conductivity and attenuation (shielding effectiveness) when compared to EC-2040. Further, the gum base product has superior tensile and tear strength compared to the discontinued gel base silicone product. Stockwell Elastomerics offers the SSP compound in sheets, cut parts and 3D molded configurations under the Stockwell Elastomerics product number SNE-540. SNE-540 is available with or without conductive peel and stick adhesive.

Nickel graphite filled silicone materials are commonly specified for commercial application where environmental sealing and EMI gasketing is needed. The Ni/C fill is considerably less expensive than the more “exotic” silver coated particle filled products often specified for military and aerospace applications. While the filler costs less than silver plated aluminum, the attenuation performance is still very good.

SNE-540 properties:
♦ Durometer: 40 Shore “A”
♦ Max Volume Resistivity: 0.030″ Ohm-cm
♦ Temp Range: -55 to 160°C (-67 to 320°F)
♦ Shielding Effectiveness: >100 (@ 20 MHz – 10 GHz)*
* Shielding Effectiveness testing was performed by DLS Testing in February 2013

For more information on SNE-540 or other electrically conductive silicone rubber for EMI shielding, please call Stockwell Elastomerics at 215-335-3005 or complete a contact form for assistance.

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