EMI/RFI Shielding


In today’s highly electronic world, electromagnetic interference is not only a persistent annoyance, it’s a liability. Affecting everything from radio and television reception, to cell phone signals, to data downloads, electromagnetic interference, or EMI (alternately called radio-frequency interference or RFI), can compromise the performance of sensitive electronic devices.

What is EMI or RFI, exactly? Simply put, it is a disturbance which affects an electrical circuit, and which is caused either by electromagnetic induction or electromagnetic radiation being emitted from an external source. The transmission of EMI/RFI is often unintentional and its presence can significantly compromise the performance of electronic devices and components.

EMI/RFI interference exists in two forms: narrowband and broadband. Narrowband is usually the result of intentional transmissions of electromagnetic radiation. Radio stations, television stations and cell phones rely on electromagnetic transmissions to operate, and may create EMI/RFI. Broadband EMI/RFI, on the other hand, occurs when the source of the interference is unintentional, like from power lines or our above example of the microwave oven. Both types of EMI/RFI may affect the performance of electronic devices.

Electronic devices can be protected from the harmful effects of EMI/RFI. Devices and components can be isolated and protected through the use of shielding film and gaskets. Gaskets are a particularly effective method of shielding electronic components and circuits from the effects of EMI/RFI. With this method, an EMI shielding gasket is incorporated into the design of the device, isolating one component from another and creating an electrical seal that blocks or contains EMI/RFI.

At Canada Rubber Group Inc. (CRGI), t transparent conductive films (TCF) are another sound option for both containing and blocking the harmful effects of EMI/RFI in electronic devices and equipment. TCFs are an increasingly common method of creating EMI/RFI shielding, especially with the high growth of the touch-capable devices in the market.. Indium Tin Oxide (ITO) is the most widely used conductive film material; however, it is not without its drawbacks. ITO film is both brittle and costly, and is not as readily transparent as the latest-generation non-ITO films now available in the marketplace.

At CRGI, we recommend using transparent conductive for EMI shielding applications. These films have excellent and uniform conductivity, which means better protection for devices. They are highly transparent, and easily withstand flexing, stretching, tension and torsion. Furthermore, the film is transferable — meaning that it can be transferred onto other substrates for shielding purposes.

CRGI can supply both gaskets and transparent conductive film for EMI/RFI shielding applications. We can produce gaskets, in simple or complex shapes, die cut from foam or other substrates, which can be used to mitigate the effects of EMI/RFI in electronic applications. Alternatively, we can provide transparent conductive film in customer-specified geometries for shielding applications.

To find out more about the EMI/RFI shielding solutions we can provide, please contact our sales department at crg@canadarubbergroup.com.