Common Shielding Metals

All electronic components must be protected from RFI and EMI. Most manufacturers take into account that there is a balance between cost and performance when designing a gasket. The construction of these gaskets is an expensive process, which uses high quality metals to promote conductivity, galvanic conductivity, and durability. The most crucial decision to make during the design process is what material to use for the gasket.

The most popular material choice for RFI shielding is pre-tin plated steel and copper alloys. Pre–tin steel is a very ideal material for applications that require a low cost solution that functions optimally in the lower GHz range.  This steel has an agreeable permeability value in the low hundreds, and ensures low frequency magnetic shielding. The tin-plating of the steel is an excellent defense against corrosion and prevents rusting.

EMI RFI Shielding

Copper, nickel, and zinc alloy are also commonly used in EMI shielding applications. These alloys can also resist corrosion and works well as an EMI shield in the mid high kHz range and up into the GHz. Copper is considered to be the most reliable material in EMI shielding and RFI shielding because it is highly effective, although there is a time and application for using nickel or zinc alloys.

• Using EMI-RFI Shielding Gaskets and Filters
  EMI filters address issues that are related to penetrations through the shield. They are also used at the outputs and inputs of electrical systems, which are widely known as the most vulnerable points of a shield.
• When is EMI Shielding Necessary
• EMI & RFI Protection for Medical Devices and Equipment