Understanding Printed Circuit Board Shielding

When it comes to controlling EMI – Electro-Magnetic Interferences, EMI shielding cans or screening covers for printed circuit boards (PCBs) are the best solutions. Shielding is a useful technique to protect the internal components of an electronic device from harmful radiation at the source. Shielding involves using enclosures that keep harmful interference out and also unwanted emissions inside. The EMI shielding covers are applied on a specific component that needs to be shield or areas on a printed circuit board to protect it from electromagnetic radiation. Shields are available in a wide range of sizes and variations to protect a sensitive signal from external electromagnetic signals. At the same time, EMC Shielding helps in preventing an unwanted internal signal from interfering with surrounding electronics.

EMC (Electro-Magnetic Compatibility) means that a circuit has been designed in a way to prevent any disruption. At the board level, shielding cans are used to cover specific problem areas of a circuit. When the EMC shielding cover is fixed on the PCB elements like IC chips or connectors, it controls emissions that are too high or are too sensitive.

EMI Shielding Applications

EMI/RFI is the worst enemy of many sensitive electronics. These interferences are responsible for causing various different issues such as a hiss on a communication line or even total disruption of a critical signal. To avoid these issues and keep the devices safe, shielding technique is used for devices across a wide range of sectors, including military, healthcare, consumer, and industrial electronics.

Shielding products are available for circuit boarding shielding, smartphones, communication devices, aerospace and military tools, microwaves, and other electronics that need protection from harmful emissions. Depending on the product specifications, you may need to choose from mesh and screens, enclosure shields, multi-level shields, Faraday cages, or PCB shields. Some manufacturers also provide custom-made shielding products based on your requirement.

Shielding Materials

Shielding at the PCB level is easy and cost-effective. However, board level shielding solutions at the product enclosure level can be complex and costs more. For shielding, various materials can be used such as brass, nickel silver, tin-plated copper, nickel silver, stainless steel, tin-plated phosphorous bronze. Tin plated cold rolled steel is the most economical material. Tin plated steel is considered to be the best option for shielding below 100 MHz because of its soldering efficiency. Aluminum should be avoided for PCB level shielding because not easily soldered.