Conductive silicone sheet is a specialized elastomeric material designed to combine the flexibility and environmental resistance of silicone rubber with electrical conductivity. Unlike standard silicone, which is an electrical insulator, conductive silicone sheet is engineered by incorporating conductive fillers—typically carbon, silver, nickel, or other conductive particles—into the base silicone polymer. This creates a versatile material that provides reliable electrical grounding, electromagnetic interference (EMI) shielding, and electrostatic discharge (ESD) protection while maintaining the softness and resilience of silicone.
This article from ElastaPro provides answers to frequently asked questions (FAQs) about conductive silicone sheet.
What is the Material Composition and Structure of Conductive Silicone Sheet?
The base polymer is high-quality silicone rubber known for its thermal stability, weather resistance, and flexibility. Conductive performance is achieved by dispersing conductive particles throughout the silicone matrix. The type, size, and concentration of these fillers determine the sheet’s electrical properties, including volume resistivity and shielding effectiveness.
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Carbon-filled silicone provides moderate conductivity at a lower cost and is often used in general EMI shielding applications.
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Nickel-graphite filled silicone offers improved shielding and corrosion resistance.
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Silver-aluminum or silver-plated fillers provide the highest conductivity levels and are used in mission-critical applications such as aerospace or defense electronics.
The result is a sheet material that can function both as a gasket and as part of an electrical grounding or shielding system.
What are the Key Performance Characteristics?
Conductive silicone sheets maintain many of the physical advantages of standard silicone rubber. They can typically operate in temperatures ranging from –60 °C to 200 °C without losing flexibility or performance. They are resistant to UV exposure, ozone, and most environmental stressors, making them suitable for both indoor and outdoor use.
Electrical properties are a key differentiator. Depending on the formulation, conductive silicone can achieve volume resistivity levels low enough to meet EMI and ESD protection requirements for electronic enclosures. The material’s surface remains pliable, allowing it to maintain good electrical contact under low compression forces.
Another important characteristic is stability over time. Unlike some conductive coatings or films, conductive silicone maintains its performance through repeated compression cycles and environmental exposure.
What are the Advantages of Conductive Silicone Sheet?
For engineers, the main advantage is the ability to achieve both environmental sealing and electrical conductivity in a single material. Conductive silicone can replace the need for separate seals and conductive components, simplifying assembly and improving reliability.
Its softness and conformability allow it to create a reliable EMI shield even when mating surfaces are uneven or subject to tolerance variations. Because it exerts lower clamping forces than metal gaskets, it is particularly useful in lightweight enclosures or sensitive assemblies where excessive pressure could cause damage.
What are Some Common Engineering Applications?
Conductive silicone sheets are widely used to fabricate EMI gaskets, grounding pads, and conductive seals. They are frequently die-cut or waterjet-cut into custom shapes for electronic housings, communications equipment, aerospace and defense systems, and medical devices.
They are also used in equipment that must meet electromagnetic compatibility (EMC) regulations, such as shielding seams, joints, and access panels in electronic enclosures. Their thermal stability makes them suitable for use near heat-generating components without loss of conductivity.
When Do You Use Conductive Silicone Sheet?
Engineers should consider conductive silicone sheet when both environmental sealing and EMI/ESD protection are required. It is ideal for gasketing around electronic enclosures, especially in applications where weight, space, or assembly simplicity are concerns.
However, for extremely high current-carrying applications or where mechanical wear is high, metal-based solutions may be more appropriate.
In summary, conductive silicone sheet is a high-performance material that blends electrical conductivity with the proven reliability of silicone elastomers. For engineers, it offers a practical and efficient solution for EMI shielding and grounding applications in demanding environments.
Contact ElastaPro for conductive silicone sheet.
