EMI Shielding from Elasto Proxy
EMI Shielding from Elasto Proxy

Doug Sharpe
President of Elasto Proxy

Today’s automobiles are equipped with automotive electronics that direct drivers and manage vehicle safety and performance. Advanced cameras check for pedestrians. Adaptive cruise control automatically adjusts your speed to stay a safe distance away from vehicles ahead. An alarm beeps or the driver’s seat vibrates if your car leaves its lane. Truck headlights brighten or dim with changes in lighting conditions and oncoming traffic. Collision warning with automatic braking can slow or even stop your vehicle.

Does your car, truck, or sports utility vehicle (SUV) have these safety features? If not, your next ride probably will. Meanwhile, automakers are incorporating additional electronics for security, navigation, communications, and entertainment. After all, technologies such as global positioning systems (GPS), Bluetooth, and other radio frequency (RF) applications delight car buyers. For electronic designers and electromagnetic compatibility (EMC) consultants, however, there are other important considerations.

What Is Electromagnetic Interference (EMI)?

Installing a large number of electronics into a small interior space can cause these systems to interfere with each other. Malfunctions or failures caused by cross-talk aren’t the only risks, however. Strong electromagnetic fields (EMFs) can affect human health. That’s why the batteries in electric vehicles (EVs) are enclosed in more than just a metal box. A shielding gasket atop the box contains EMFs and prevents electromagnetic interference (EMI) from the battery from disrupting other electronics.

EMI gaskets are also used with the inverters and converters that manage the power and recharging circuits in electric cars and hybrid electric vehicles. Shielding gaskets are also needed at EV charging stations, where multiple chargers can generate strong EMFs as well as EMI. Paying for an EV charge could pose a problem, however. Electronic cash registers have drawers for dollar bills, and point of sales (POS) systems use electronics for credit card processing. Both need EMI gasketing.

EMI shielding isn’t just for electric cars and hybrid vehicles, however. Luxury automobiles powered by gasoline or diesel engines use cameras, sensors, and radar. As more mid-range models add automotive electronics, carmakers will need EMI shielding solutions that balance performance with cost. For EMC consultants and designers of automotive electronics, it’s important to know which shielding materials work best – and which gasket fabricator can meet all of your requirements. 

Particle-Filled Silicones for EMI Gaskets

EMI gaskets aren’t new, but some buyers still think that particle-filled silicones are too hard, too brittle, too expensive, and too thick for automotive electronics. Loading a high percentage of particle filler into silicones can result in tough tradeoffs, but Elasto Proxy sources innovative elastomers that address these concerns. The shielding materials we recommend balance electrical conductivity with cost-effectiveness, and provide benefits that strengthen your electronic designs.

For example, the particle-filled silicones we source can be used in shielding gaskets that are thin, flexible, and able to withstand the high temperatures associated with automotive engines. Silicone gaskets from Elasto Proxy also provide environmental sealing. Fluorosilicone gaskets are available for automotive applications that involve contact with fuels or solvents. Silicones provide many desirable properties, and compounding this rubber makes it a great choice for EMI shielding.

Today, silicone gaskets that are filled with nickel-coated graphite particles are used between metal enclosures to protect automotive fuses. Elasto Proxy can also source semi-conductive silicones filled with carbon black for static dissipation. Both conductive materials are available in continuous rolls, a form factor that promotes the cost-effective fabrication of EMI shielding. Elasto Proxy can also source particle-filled EMI shielding as uncured moldable compounds and compression molded sheet stock. 

How Can We Help You?

For over 25 years, Elasto Proxy has custom-fabricated specialty seals and custom insulation for a wide range of industries, including automotive and mobile specialty vehicles. How can we help you with EMI gasketing? Contact us today, or join the conversation about this blog entry on LinkedIn, Facebook, Google+, and Twitter. Elasto Proxy has a YouTube channel, too. There, you’ll find our Capabilities video, as well as other informative content. Finally, please subscribe to our free e-newsletters.