Radio frequency shields are vital components in sensitive applications that block out electromagnetic interference from nearby devices. The strength of the shield depends on several factors, including the thickness and composition of the material used for shielding. Based on the application of your equipment, you’ll have to choose the perfect material depending on weight, conductive properties, or even for cosmetic reasons.
What is Radio Frequency Shielding?
Radio frequency shielding, also known as RF shielding, is a part that blocks electromagnetic interference (EMI). Simply put, it’s a part made from metal materials that prevent waves from damaging your valuable equipment. Whether in aerospace, healthcare, defense, or communications, choosing the most appropriate material for your application is vital.
What Materials Are Best for EMI/RFI Shielding?
There are multiple types of materials that can be used for EMI/RFI shields. The most effective material for this purpose is typically copper, followed by bronze. Aluminum, gold, and brass are also worthy options. It’s dependent on the type of electronics being protected and the frequencies that need to be repelled.
The effectiveness of these metals in preventing interference from penetrating the shields depends on their thickness and how each material is applied to the surface being protected.
Picking the right material is crucial. Read on to learn more about each material and find the right one for your part.
Copper
Copper is a good conductor of electricity, heat, and electromagnetic radiation. It is also a great conductor of sound waves, light photons, and radio waves while blocking radio frequencies. Copper is the typical choice for MRI machines and other medical equipment.
Working with copper presents an array of benefits. Some of these include:
- Easy to solder, braze, and weld
- Inexpensive
- Easy to process
- Highly conductive (electric and thermal)
- High flexibility/malleability
- Will stick to nearly any finish, including gold
- Conforming coatings can provide anti-oxidation characteristics for PCB applications
When choosing conductivity as your main criterion for an EMI/RFI shield material, copper is the best option because it conducts so many different types of energy and it holds up well to changing temperatures and altitudes.
When choosing an appropriate material for EMI/RFI shields, it is essential to consider extreme conditions. Copper is often our first choice in these situations.
Read more about how E-Fab uses copper and copper alloys.
Brass
Brass is an alloy of copper and zinc. It is a good EMI/RFI shield material used in many applications, including medical devices, electrical contacts and connectors, RF connectors and solder joints, and relays.
There are many benefits of working with brass, including
- Affordability
- Electrical resistance
- Corrosion resistance
- Wear resistance
- High-temperature tolerance
- Formability and machinability
- Compatibility with finishing treatments
Read more about how E-Fab uses brass.
Aluminum
Aluminum is a good conductor of electricity and heat, which makes it an ideal choice for EMI/RFI shielding. It is lightweight and strong (it can withstand greater pressure than steel) but also inexpensive.
Aluminum’s low density allows for thinner sheets with the same strength as thicker sheets made from other metals. This means you can save money using aluminum shielding instead of heavier metals like lead or iron.
Aluminum is one of the top choices for commercial and industrial parts, components, and products. This lightweight metal is strong, reliable, and versatile. It also comes in multiple grades that offer corrosion and fatigue resistance and may be anodized when required.
The main benefits of working with aluminum include:
- Affordability
- Versatility
- Durability
- Lightweight
Read more about how E-Fab uses aluminum.
Gold
Gold is an excellent metal for EMI/RFI shields, especially in applications where high frequencies are in play. We use gold for plating.
Gold’s conductivity increases with frequency, which makes it especially effective in applications where radio frequencies are used as energy sources (such as in cell phones or WiFi routers).
Gold is also a dense metal designed to be very thin — this makes it ideal for use in products such as smartphones and computers, where space is often limited.
Lastly, because gold resists corrosion and oxidation and has excellent thermal properties (it doesn’t melt until 1,064 °F), it lasts longer than other materials under harsh environmental conditions like moisture exposure or high temperatures like those found inside electronic devices.
Nickel
Nickel and Nickel Alloys make for excellent EMI/RFI shielding materials in low-frequency applications. It is a durable material that stands up to corrosion and features excellent mechanical properties such as strength, high-temperature tolerance, and versatility across several industries.
Read more about how E-Fab uses nickel and nickel alloys.
What Materials to Avoid
It’s not always black and white when choosing a suitable material for EMI/RFI shields. Some materials can block radio frequencies but might not be the best long-term choice. These metals include steel, zinc, and magnesium due to durability issues and unwanted reactions when in contact with other metals.
Work With the Experts at E-Fab
Don’t take any chances when picking the right materials. E-Fab’s engineers, materials experts, and quality assurance professionals can help select the material best for your project.
