From electric vehicles and consumer electronics to medical devices and airplanes, EMI shielding plays a vital role in preventing disruptions in essential areas of our everyday lives.

What is EMI Shielding?

According to ScienceDirect, electromagnetic (EM) shielding is an “electromagnetic shell (entity or nonentity) made of the shielding materials (conductive or magnetic material), which forms a close electromagnetic shielding region and shields the electromagnetic wave.”

In other words, EMI shielding is a barrier that is used to minimize electromagnetic radiation in a given space. It comes in many forms and materials, including plastics, metals, and textiles.

What Does EMI Shielding Prevent?

Electromagnetic interference (EMI) comes from both artificial and natural sources, and it can cause a range of problems, from minor telecommunication issues to significant system failures. EMI shielding helps prevent these electromagnetic signals from disrupting other components. It also prevents generated signals from disrupting the surrounding parts.

On a large scale, EMI shielding prevents disruptions to mass transit, manufacturing, and navigation, playing an essential role in the functioning of significant industries, including automotive, defense, aerospace, and telecommunications.

EMI shielding prevents interruptions in cellular and radio communications, protects the electrical grid from malfunctioning, and prevents interference in aerospace function and communication. EMI shielding is also used in several types of medical devices to prevent interference and preserve patient safety. In the defense industry, technology like military computers, drones, and aircraft emit large volumes of electromagnetic radiation. EMI shielding is essential in preventing interference from compromising these defense systems.

EMI shielding plays a large role in the function of electric vehicles, which are significantly more susceptible to interference than gas-powered vehicles. There are several sources of EMI from within electric vehicles, including electric motors, transaction batteries, collision avoidance radar, shielded and unshielded cables, and engine control modules (ECM). Without proper EMI shielding, interference from any of these sources could cause severe problems in the operating system of an electric vehicle.

EMI shielding can also help protect electrical and electronic components from damage and malfunctioning that can result from corrosion and heat.

How Does Shielding Reduce EMI?

Multiple shielding materials are used to reduce EMI; the most common are acrylic-based sprays and coating, high-performance plastics, and polymers plated with metals.

High-performance polymers like PEEK and Ultem allow “engineered enclosures to be manufactured to exacting standards.” They can help reduce EMI and protect against extreme heat and highly corrosive environments, particularly when coated with EMI shielding metals. Ultem has outstanding thermal stability that makes it an excellent choice for extreme environment applications; while PEEK too has good thermal stability, it also has a strong chemical resistance and a high stress tolerance, ensuring long-term durability. 

Polymers plated with metals like copper, nickel, tin, silver, and gold gain the ability to reflect the interference back to its source. The use of these metals offers additional protection. Some experts prefer copper and nickel because they are highly effective against both magnetic and electrical waves.

The Future of EMI Shielding

As the automotive, aerospace, medical and other industries continue to rely on high-tech communication, AI and battery power, EMI shielding will become even more essential to ensure equipment performance and consumer safety.