EMI (electromagnetic interference) is either electromagnetic induction or electromagnetic radiation from an external source that is interfering with the performance of a nearby circuit. While the source of EMI can be any entity carrying an electrical current (including the sun), the term EMI is usually used when referencing an electrical circuit’s ability to perform efficiently without being affected by electromagnetic devices within its immediate vicinity. Interference—or EMI—from these competing devices can cause the disruption or blockage of the efficiency of the circuit in question, or in some cases cause circuit shutdown. Depending on the application, the failure of a key circuit and surrounding hardware can create substantial financial and safety concerns.
The barrier against the potential hazards of EMI is EMI shielding, which can come in the form of conductive enclosures that block electromagnetic radiation, specially designed gaskets, conductive paints and coatings, foils and tapes, and EMI filters. Gaskets designed to inhibit EMI include finger-stock gaskets, fabric-over-foam gaskets, mesh gaskets, and gaskets made up of a combination of materials. In the end, the goal of each of these shielding approaches is the same: effectively protecting electrical and electronic devices against potentially damaging EMI (reducing or eliminating “noise”).MI (electromagnetic interference) is either electromagnetic induction or electromagnetic radiation from an external source that is interfering with the performance of a nearby circuit. While the source of EMI can be any entity carrying an electrical current (including the sun), the term EMI is usually used when referencing an electrical circuit’s ability to perform efficiently without being affected by electromagnetic devices within its immediate vicinity. Interference—or EMI—from these competing devices can cause the disruption or blockage of the efficiency of the circuit in question, or in some cases cause circuit shutdown. Depending on the application, the failure of a key circuit and surrounding hardware can create substantial financial and safety concerns.
The Rapid Growth of Wireless Technology
Due to staggeringly rapid advances in wireless technology, and the ongoing miniaturization of electronic devices, the EMI shielding industry continues to grow at record rates while facing an onslaught of new challenges. Wi-Fi, GPS, 3G, RFID, Bluetooth, extremely complex cell phone and tablets—all of these developments create both more opportunities for problems caused by EMI and more opportunities for EMI shielding designers to solve them. Almost all of today’s power electronics are built with EMI filtering circuits or include internal EMI filters, both of which require the skills of an EMI shielding designer. Wireless communication, aerospace, healthcare, automotive, defense, and consumer electronics are just a handful of the industries across the world that require effective EMI shielding within their electronic device systems.
EMI is generated almost anywhere on earth, and the amount of electronics requiring protection from it is only going to continue to grow. According to BCC Research estimates, the global EMI shielding market is expected to reach $6.6 billion by 2019 (BCC Research Report EMI/RFI: Materials and Technologies, October 2014). Phones keep getting smaller and faster, wireless communication systems within hospitals continue to get more complex, navigation and entertainment systems within cars keep offering more and more features—with every advance in electronic technology comes a new demand for EMI shielding. Simply put, it all needs protection, from issues as small as a minor inconvenience (loss of personal cell phone reception or internet connection) to situations where lives may be at stake (military communication systems, jetliner electronics, EKG monitoring systems, etc.).
EMI Shielding and the Automotive Industry
A conversation regarding the current state of the EMI shielding industry would be not be complete without discussion of automobile manufacturing. The average car coming off the assembly line in 2016 is host to a long list of standard features that would have been considered luxury options less than ten years ago. Onboard GPS navigation systems, Bluetooth capabilities, touchscreen entertainment systems, hands-free feature operation—all of these elements bring us a new level of driver convenience while also creating more opportunities for issues resulting from unwanted EMI. In addition to the sheer increase in automobile electronics themselves, there’s also been an overwhelming rise in the amount of interference noise created within and around cars themselves due to cell phones, tablets, and other wireless devices.
The more advanced the electronics in a vehicle become, especially those related to engine performance, the more crucial the need for effective EMI shielding becomes. For this reason, auto manufacturers are now approaching EMI shielding companies earlier in the design process than ever before, looking for smart solutions to newly created shielding needs. Even excluding relatively new technology like in-vehicle Wi-Fi networks, wireless phone chargers, and voice-activated controls, EMI within new cars and trucks is becoming more and more dense due to the proliferation of electric motors and electronics across all areas of the vehicle (automatic sliding doors, remote starters, power seats, keyless ignitions, power windows, etc.). The motor within each of these components stands to generate EMI that could interfere with electronics within the vehicle, and thus requires some sort of EMI shielding to ensure its compatibility with the rest of the car.
Designing a shield that meets the needs of today’s newest vehicles can be costly to the auto manufacturer, but it is a task that should be started as early as possible. If an EMI issue is discovered late in the manufacturing process, and vehicle components are already on assembly lines, production may have to stop while engineers look for a solution to the problem. Oftentimes, the biggest challenge in engineering an EMI shield is knowing when the shield is needed—EMI signals, especially in a crowded environment such as within an automobile, can be so small that it’s not initially known exactly which components need protection and how much. With this in mind, EMI shielding is always most effective when considered at the same time an electronic component design is started. If EMI is not a high priority at the beginning of the design process, working retroactively to create a suitable solution can be extremely expensive and also lead to a shielding setup that is not space-efficient.
Evolving automobile materials have also played a role in the shape of today’s EMI shielding industry. Most conventional cars are made with sheet metal that naturally shields internal electronic components from outside EMI—in this case, shielding designers have only the task of shielding EMI created within the vehicle. As more car manufacturers turn to non-metallic materials for auto body construction, new EMI shielding challenges are emerging. Additionally, today’s smallest cars (with the least amount of metal shielding) are often hybrid or electric vehicles, with electric drivetrain components that create a large amount of EMI. In this case, EMI shielding designers have more EMI to contend with and less sheet metal to assist in shielding the rest of the vehicle from it. As car manufacturers continue to rely on more non-metallic body materials—and continue to add more electronic/wireless components to vehicle designs—EMI shielding producers will need to look for new ways to solve these challenges while keeping shielding design costs in a reasonable range.
Technologies Evolving in Both the Business and Personal Sectors
As electronics technologies continue to quickly evolve in arenas like aerospace, healthcare, military, and telecommunications, rapid advances are also taking place in the design of wireless consumer products such as personal drones, tablets, cell phones, laptops, GPS systems, and fitness trackers. As these items continue to cram more and more features into smaller and smaller footprints, the space available for effective EMI shielding also gets smaller and smaller. With this upswing in potential EMI issues factoring into a large number of design orders, many EMI shielding manufacturers are finding their design departments becoming increasingly specialized as they successfully meet the needs of very specific markets (i.e., a drone manufacturer now has the ability to choose a shielding partner based on specific success with shielding designed for use within drone technology).
Accompanying this wave of new wireless products are tightening FCC regulations. For EMI shielding specialists, what this means is figuring out new ways to use less space and thinner/lighter materials while creating shielding to tighter tolerances. This sounds like a tall order, but for experienced shielding designers, meeting these challenges is an evolutionary rather than revolutionary process. While space is at a premium and costs need to be minded more than ever before, the task at hand remains the same—choosing the shielding strategy that will best suit the application in question and designing a shield that will successfully deter outside interference. Size, noise ratios, certifications, temperature tolerances, and environmental conditions are all carefully considered as a design comes into fruition.
EMI Shielding Industry is Only Going in One Direction
Electronic devices are getting sleeker, smaller, and more advanced. Driverless cars are on the horizon. Endless numbers of wireless components are transmitting signals within increasingly confined spaces. The need for effective EMI shielding is only going to increase as the world continues to shrink and the demand for speed and convenience continues to grow. For EMI manufacturers, the key to staying ahead of the curve is getting involved in the design process as soon as possible. If interference levels, shielding compliance guidelines, energy stability, and time to market are all considered and addressed long before a component is on the assembly line, the more likely it is that an effective (and cost-efficient) shielding solution can be found.
As the global demand for integrated electronic components continues to expand, the EMI shielding industry will also continue to grow and evolve. Size and cost will remain our biggest issues, with design and regulatory compliance also playing large roles in shielding development. EMI can be found almost anywhere, and it doesn’t take much of it to disrupt the performance of electronic systems of all kinds. With the right materials, the right design, and the right manufacturing process—at the right time—successful EMI shielding can be achieved across even the most complex of applications.