EMI Shielding Finish Depends on Environment Class

Few materials are not subject to corrosion. Metal is not one of them because it has innate tendencies to react to be stable in its environment. The reactions will be either chemical or electrical (in some cases both). When constructing most electronic packages, special design considerations must be taken based on 1 of 4 general environment types.

  • Class D: Airspace, Outer Space Environments
  • Class C: Aquatic, Marines, Water Environments
  • Class B: Outdoor, Uncontrolled Environments
  • Class A: Controlled, Enclosed Environments

The finish that parts are given can help to eliminate or substantially decrease corrosion properties. We can provide tables with the necessary minimum requirements for finishes so that they protect against chemical corrosion while delivering an electrically conductive surface.

For instance, carbon and steel alloys in a Class A environment require:

0.0003 in. Tin
0.0005 in. Zinc Plate
0.0003. in. Cadmium Plate

In a Class C environment, the following is needed:

0.001 in. Tin
0.003 in Nickel

Working with our talented team is the best way to determine class and finishes that are necessary for your parts. Let us help you design and create the best possible EMI shielding and RFI gaskets.