EMI coating is sprayed on the interior of electronic device housings in order to protect sensitive electronic equipment from electromagnetic interference.
EMI, or electromagnetic interference, is the magnetic field which is created by electrical currents; EMI can travel along wires, electrical circuits and conductors, while radio frequency interference (RFI) is radiated electromagnetic “noise,” which travels through the air as radio waves.
Shielding sensitive electronic equipment from electromagnetic interference (and shielding high EMI-emitting equipment from contaminating other equipment) can be achieved by blocking the EMI with a conductive by coating equipment or equipment enclosures with EMI coating. EMI coating allows for more flexible applications than EMI enclosures, as it may be spray-coated to any number of enclosures, areas and insulators.
Various types of EMI coatings are often spray coated to the inside of plastic enclosures, surrounding the equipment which needs to be shielded in order to absorb harmful EMI and RFI. “Metal inks” containing copper, nickel or chromium alloys are EMI coatings which may be sprayed on to virtually any housing or material to create the effect of EMI shielding.
Electronic equipment manufacturers and suppliers use EMI enclosures in applications such as circuit board housings, central processing units, laptops and mobile phone housings. With circuit boards, CPUs, laptops and similar devices, most problematic EMI comes from electromagnetic cross-talk within the device.
Different components on the same board cause EMI to travel across wires and conductive materials, interfering with one another. EMI coatings may be sprayed onto wire insulation, circuit boards and onto the interior of small enclosures of integrated circuits, diminishing electromagnetic “cross-talk” within devices.