Protection Against a Disturbance in The Force

EMI Shielding Blocks Interference

Electromagnetic Interference (EMI) most commonly occurs in the frequency range of 104 to 1012 Hertz. Some of the most common sources of EMI are from radio transmitters, electric motors, fluorescent lights, power lines and computer circuits. If EMI shielding is not in place to protect sensitive electronic components, device failure can result from electromagnetic spectrum interference. EMI has been known and understood for almost 100 years back to the time of early signal transmission. Currently, EMI shielding has become a fundamental and necessary part of designing an electronic circuit. 

Electromagnetic Interference impacts an electrical circuit through interference from electromagnetic induction or RF transmissions. Interference can degrade, interrupt, limit or completely obstruct the performance of a circuit.  While EMI can be an unplanned occurrence, during a time of war it is extensively used as a method for jamming radio or radar transmissions.

Common EMI Shielding

EMI shielding is commonly produced by carefully grounding the electronic circuitry or by creating what’s known as a Faraday cage around the circuit. A Faraday cage is basically a screen of conductors placed around the electronic circuit which is then carefully grounded. A common example of a Faraday cage is the protective metallic mesh that covers the glass on a home microwave. When you step into an elevator and your phone call drops, this is a result of the metal enclosure of the elevator acting as a Faraday cage trapping your cell phone transmission.

Need to Reduce Shielding Size

As semiconductors continue to shrink and interconnect node sizes reduce toward sub 10 nanometer designs, EMI shielding must follow suit. Toward that end, vacuum metallization by evaporation or sputtering has been employed for many years to coat plastic components that contain electronic circuits.  Recent techniques have been developed to deposit thin films of conductive EMI shielding directly onto wafer level and chip scale packages. This process allows for high speed deposition of EMI shielded coatings prior to wafer dicing while still maintaining excellent circuit protection and smaller size.

Materials for EMI Shielding

Materion is a leader in producing sputtering targets for advanced EMI shielding applications. Common materials include chromium, copper, molybdenum, nickel alloys, tungsten and titanium. Materion provides target materials to several leading OEMs in the growing field of wafer level EMI Shielding. For more information about Materion products, contact Matthew Willson, Director of Marketing, Matthew.Willson@Materion.com.