Most Popular Materials Used for Electromagnetic Shielding
You quite often have heard a certain type of distorted noise in the speakers when receiving a call or message on a nearby cell phone or witnessed the distorted TV pictures due to signal issues. Well, if you have always been wondering why that happens, keep reading further.
These unwanted noises and distortions occur due to a phenomenon called Electromagnetic Interference (EMI) where the electromagnetic fields of different electronic devices interfere with each other and distort the magnetic fields. EMI is a huge problem on electronic devices as the electromagnetic radiation is easily picked by the conductor placed near it.
Usually, the radio frequencies ranging between 1 kHz and 10 GHz are the major sources of interferences. Other reasons can be solar magnetic storms, thunder lightning, power surges, voltage fluctuations, etc. All this can have varying levels of consequences from temporary signal disturbance to loss of life at worst. This is the reason why people are asked to switch off their electronic gadgets in the airplanes as they can hinder the communication between the pilot and the on-ground staff.
Having said that, it is vital that you develop an effective form of shielding against EMI to keep the electromagnetic waves inside a specific area or protect them from the external area. EMI can be effectively blocked with the help of certain types of specialized materials depending upon the type and intensity of frequencies.
However, with little or no knowledge, one is bound to get confused for picking the right type of shielding. Here are the most common types of EMI shielding materials used globally –
Pre-Tin Plated Steel
It is the most cost-effective shielding solution available in the market. It works great for controlling frequencies ranging from lower kHz to low levels of GHz. Such a quality is generally missing in copper alloys and aluminum.
The tin plating on these shielding enclosures offers extraordinary solderability and protection against corrosion.
Copper is just the right material choice (for shielding against the disturbance of radio frequencies) because of its high conductivity attribute. Copper can be used either as a base metal or as an alloy depending upon the requirement of the project.
This material option is an appropriate choice if durability, flexibility and rust prevention is all that you need.
Copper Alloy 770/Nickel Silver
Copper Alloy 770 is basically a composition of copper, nickel, and zinc resulting in the formation of a metal known as Nickel Silver. It is silvery in appearance and has tremendous corrosion resistance power, anti-galling properties, and cryogenic performance.
Due to these reasons, they make up for an appropriate choice for EMI shielding applications.
This material is yet another cost-effective option that offers immense versatility in case of RF shielding. Its high conductivity and non-ferrous properties make it an ideal choice for a number of other applications as well.
However, this metal demands a lot of attention due to its easy oxidation property. Although it is easily prone to galvanic corrosion and has lesser solderability, it is being successfully used for shielding.