Information on variables that influence the performance of an RF shielding enclosure can help users make the right choice. Most of the work in improving and maintaining the RF shielding performance of an enclosure falls on the selected material. Generally, copper, aluminum and steel-based materials of different design and structure are used for shielding enclosures. However, without proper information, it can be confusing to pick the right material to build the enclosure. In this article we are going to explore the characteristics of these three popular metals that make them efficient for RF shielding.
Copper as a base metal and in its alloy form can both be used in an array of projects. Being easy to manufacture and form into preferred shapes, copper-based RF shields can be installed faster than other materials. Plus, its high conductivity feature makes it an efficient shield against RF. Copper is easy to manage as it has natural resistance against oxidation in the environment. Although, copper is easy to mold into a number of shapes, it is quite durable as well.
Copper can avoid or slow down the progress of corrosion as it is cathodic by design. However, if other metals are able to penetrate or perforate the copper shielding design, then it will have to be plated to maintain shielding performance and to keep the corrosion at bay. Copper-based shielding can also be quite costly, presenting a problem to be used in low attenuation shielding.
Steel is another commonly used metal for RF shielding. Although, steel-based alloys show magnetic field shielding capability, this type of shielding doesn’t offer as high of attenuation as copper and aluminum can. Users can choose the preferred characteristics in metal alloys by using various development processes like hot rolling, cold rolling and grain orientation. However, you should have a clear understanding of these development choices before selecting one. Here are a few features that these development processes can offer in steel shielding.
Cold rolled steel can offer better shielding capabilities.
Annealing can enhance the magnetic properties of the metal.
Hot rolled steel can offer better mechanical efficiency and durability.
Cold and hot rolled steel both display a scaly surface if annealed.
Oxidation on steel surfaces is common. It should be cleaned off from the mating surfaces (where other metals penetrate or perforate steel) to maintain performance.
Aluminum is a versatile component when it comes to RF shielding. It can be used as a foil to block low frequency radio fields or it can be integrated in construction to offer a built-in shield against radio frequencies. Although, you can make it tear-proof, it doesn’t exactly offer high resistance against natural weather, so users should beware of oxidation. Exposing the material completely to the environment, however, can also help in creating a natural barrier against corrosion.
The metal that a manufacturer should use will typically depend upon the product in hand. Contact us if you are looking for the appropriate shielding solution for your project.