Tips For RFI and EMI Shielding

Electromagnetic shielding--commonly known as EMI Shielding-- limits the electromagnetic field in an area by blocking the fields with barriers. Each barrier is made of a conductive, or magnetic, material. Typically, shielding is applied to the casings of electrical devices in order to limit disturbances from the outside world.  Additionally, EMI shielding is applied to cables to isolate wires from the environment in which the cable runs through. A popular form of Electromagnetic shielding is called RFI shielding. This practice blocks radio frequency electromagnetic radiation. In order to keep RFI and EFI shields functional there are many management techniques that can help.  If you are experiencing problems with your materials there are trouble shooting methods that you can run through to find a solution:

These are some tips for proper EMI/RFI management tips.

Frequently asked questions

  • How do I remove heat from the components inside of the EMI/RFI Lids /Covers?
  • When solving heat issues, ventilation holes along the top surfaces help to remove heat from inside the shielding can. Additionally, higher power chips may be a better thermal management practice. The chip has to be applied to the EMI/RFI can/cover prior to attachment to the circuit board. Heat the lids to above 60 degrees Celsius before attachment because the temperature allows good flow to limit any trapped air gaps.

  • Is the most cost effective method for covers of cellular phones and other device dispensing and curing a conductive rubber gasket compound?
  • Form-in-place gasket placing is traditionally the most cost effective, in terms of material, but may be more expensive in terms of manufacturing. Using pre-form shaped-gaskets, with conductive pressure sensitive adhesives as a high volume, can be an alternative to the form-in-place EMI/RFI shielding gasket.

    For RFI shielding, ineffective gaskets are the biggest reason behind faulty RF gaskets.  This is largely a problem that is derived from faulty installation. Essentially, the gasket is placed in a position where a gasket was never meant to go.

    The Ideal gasket surface is conductive, rigid, and recessed to completely house the gasket.

  • If there is an EMI/RFI shielding leakage, what should be used to solve the problem
  • Use a conductive caulk to fix the problem

  • What should I use to if I need to have a see through window in my design?
  • A blackened mesh should be used if a see through window is required.

Related Reading

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