Elimination or mitigation of interference or noise due to radio frequency (RF) or electromagnetic waves is a crucial aspect in electrical, electronic, or electromechanical devices as well as SCADA or integrated systems. This can be done through suppression or filtration of EMI signals by using various tools and techniques such as grounding, shielding, and more. This should be such that it filters EMI at board level as well as device or system level, which means waves coming from internal as well as external components. Here, it is important to consider the external EMI that may hamper the inner board components. To avoid this appropriate grounding and electrical connectivity is essential between the device and PCB. This is achieved with the help of EMI-shielding gaskets. This post discusses some pointers which may help choose the right gasket to protect your device and its PCBs from EMI.
Factors to Consider When Choosing Gaskets to Shield EMI
Here are some factors you may want to consider when choosing gaskets for EMI shielding at device and board levels.
- EMI shielding gaskets can be made of various materials ranging from metal, silicone, conductive foam, fabric, conductive elastomers, and more. You need to find out the suitability in terms of your device or application, such as flexibility of the gasket, electrical conductivity, holes for ventilation, the amount of cushioning required, operating environment, and so on.
- When choosing gaskets for the device, you need to consider if it will also offer benefits at the board level. Also, must suppress interrupting signals coming from the outside environment or nearby devices to avoid buzzing noise, flickering lines on displays and monitors, and so on.
- Select the dimensions correctly based on the area available, size of the device or system, thickness required, and more.
- Weigh all these factors against your application requirements in terms of operating temperature, compression ratio, material hardness and flexibility, compression and conformity, soldering strength, thermal and vibration resistance, and other such properties of the material used.
- Check if the shield can be removed and attached again. This is important in terms of the PCB shields as well. They also must be removable and easy to reassemble. This helps rework on the board, add or remove components, or upgrade it as required.
- Check if the gasket matches specific and standard industrial compliances such as MIL-SPEC, FCC, CE, and so on.
- After assembling the gasket onto the device or system, you need to check if it meets the required frequency range and attenuates EMI signals without hampering transmission or reception signals.
- Before selecting a device gasket, ensure the PCB shielding requirements are met. This is because complex PCB designs with several components are commonly used in many devices, and are the possible source of EMI within. So, to ensure normal functioning of the device, PCB EMI shields are as important as shielding gaskets. It is important that these PCB shields are flexible, removable, protect the mounted components, and conform to the exact size and shape of the board. This will also help save space within the device.
While gaskets are used to protect devices from external EMI, efficient board level shielding solutions are crucial for effectively managing EMI produced within the board. All of this together facilitate uninterrupted functioning of the device. Whether gasket or PCB shields, it is essential to source them from reputed and certified manufacturers. For board level shielding, you can absolutely trust XGR Technologies. The company offers SnapShot® EMI shields that are lightweight, flexible, and offer isolation for a wide frequency range from below 1 GHz to 12 GHz. They are made of plasticized metal, and hence they stay firmly in place while also being bendable. Once this board level factor is sorted, choosing the right gasket would be easy. In case you require board level shielding solutions or have any questions pertaining to PCB EMI shields, you can contact the XGR Technologies team today.
