Printed circuit boards nowadays are complex with multiple layers, components, and so on. Additionally, the size of these boards is shrinking, these components need to be mounted carefully in a small space. All of this makes them susceptible to EMI, and more so in case of design-related issues. Electromagnetic interference (EMI) or noise occurs when signals from two or more components on a circuit or devices on a network get mixed. This creates signal distortion which must be mitigated as it hampers the functioning of the device or product and may even damage the circuit. To mitigate this issue in printed circuit boards (PCBs), EMI shields are used. They protect the components from external noise as well as isolate EMI from components within the circuit. There are various EMI shields as well as shielding techniques. This post discusses some popular EMI shielding techniques.
Get Introduced to Some Widely Used EMI Shielding Techniques
The following are a few popular EMI shielding techniques used at device level as well as board level. Here are some EMI shielding techniques.
- Copper Shielding: Copper is a highly conductive material that is used to shield PCBs from EMI. Copper shielding can be added to the entire PCB as a layer or for individual components. This EMI shielding technique creates a shielded layer that protects against EMI. Individual copper components such as copper tape, copper foil, or copper mesh can also be used to shield specific areas of the PCB.
- Conductive Coatings: In this method, Conductive coatings such as epoxies and paints are applied to the board surface which helps shield against EMI. These coatings create a conductive layer that blocks EMI and can be applied to the entire board or certain areas that are susceptible to noise due to any reason.
- Shielding Cans: Also known as metal cans, shielding cans are metallic enclosures placed around the PCB to shield it from EMI. These are typically made of aluminum or steel and are designed to fit tightly around the board. Shielding cans find applications in mobile phones and tablets.
- Ferrite Beads: Ferrite beads are small components placed on the PCB to suppress EMI. Ferrite beads are made of a ceramic material that contains iron oxide and other metal oxides. They work by absorbing high-frequency EMI and converting it into heat.
- Grounding: Grounding is a EMI shielding technique that involves connecting the board to a ground plane or earth. Grounding helps mitigate EMI by providing a low impedance path for EMI to flow to ground. This technique is commonly used in PCB designs to reduce EMI.
- Board Level EMI Shielding: These are shields designed in one-piece and two-piece designs, which help isolate board level components, reduce EMI and minimize crosstalk. These shields are usually made of metals, however, some manufacturers are experimenting with different metallized plastic materials to reduce the weight of these boards.
Among these, the board level EMI shields have emerged as one of the most popular EMI shielding techniques. If you have been considering board level EMI shields then ensure to partner with a reliable and experienced player like XGR Technologies. The company offers SnapShot ™ EMI shields that provide shielding effectiveness from below 1 GHz to 12 GHz, which is why they have been used in mission-critical applications, including avionics, navigation systems, medical equipment and military drones. They offer consistent isolation across a wide frequency range. Made of plasticized metal, these multi-cavity shields are lightweight and flexible. They can be easily removed and reinstalled in case the PCB needs any rework. They are absolutely safe and prevent shorting as these shields have non-conductive interior surface which reduces electromagnetic coupling. You can contact XGR Technologies team today to know more about these EMI shielding techniques or share your requirements.
