Electromagnetic interference (EMI) or noise is a phenomenon that occurs when signals from two components in a circuit or two devices on different circuits clash with each other. This leads to crosstalk or noise which may hamper the functioning of the circuit and subsequently the entire device. Hence, this needs to avoided at all costs. EMI is commonly produced in printed circuit boards as well. There are many solutions for preventing EMIs, such as EMI shielding tapes, shielding cans, board level shields, and so on. All of these in one way or the other act as an insulation layer on the boards which may be conductive or non-conductive depending on the requirement. While board level shields have been found to be the most effective, this post draws comparison between the commonly used EMI shields and shielding tapes.
Comparative Account: EMI Shielding Tape or Board Level Shields
EMI shielding, in whichever form or type, is absolutely crucial. But, how to select the right type? Some important and obvious factors include materials used, level of noise tolerance, customizability, cost, and more. Here are some comparison pointers between EMI shielding tape and board level shields which may offer some clarity when choosing one.
EMI Shielding Tapes
EMI shielding tapes are self-adhesive films that offer protection from noise and are designed to resist corrosion, abrasion, and have flame retarding feature. Here are some pointers about EMI shielding tapes.
- Their adhesives may be conductive or non-conductive.
- These are mostly made of aluminum and copper foil.
- These tapes have very wide applications and are widely used to protect any sensitive devices, keyboards, cables, medical devices, shielding rooms, connectors, and so on.
- They are a cost-effective solution for protecting these devices from EMI.
- Some types of these tapes are also used to shield PCB EMI.
- However, they may pose certain challenges such as making the board rigid, adding weight to the board, and more. Some of these tapes may not be easily removable making it difficult to do any changes to the board.
Board Level Shields
These are also EMI shields but are specifically designed for printed circuit boards. They help protect the circuit and components on the board and prevent mixing of signals within the board. Here are some pointers about board level EMI shields which make them suitable for PCB EMI mitigation.
- These are multi-cavity shields widely used in circuit boards of noise-sensitive devices and systems such as radios, aerospace equipment, drones, GPS and navigation systems, and so on.
- They are super flexible and lightweight and hence do not add their weight to the board.
- These shields are easy to remove and can be reinstalled just as easily. Hence, it is easy to rework on a board which has this type of shield.
- Their outer surface is conductive, while the inner surface is made from non-conductive thermoplastics such as polyetherimide.
- They consume less space and can be easily cut into the perfect size that fits the board. The size or shape of the board does not matter.
- These shields absorb mechanical shock and vibration well.
As an OEM of electromechanical or electronic products that requires a good quality PCB assembly, you may have considered solutions for mitigating EMI. This is essential for the normal functioning of your product. Hence, it is essential to get the best quality EMI shielding tapes or board level shields. XGR Technologies offers SnapShot ™ EMI shields that offer isolation for a huge range of frequencies from below 1 GHz to 12 GHz. These shields are made of plasticized metal and are super lightweight. While they stay firmly in place, these shields can be easily removed and reinstalled in case you need to make any changes to the board. The shields have non-conductive interior surface which reduces electromagnetic coupling. You can contact XGR Technologies team today to know more about these EMI shields or share your requirements.
