Flexible EMI absorber sheets

The EMI flexible absorber sheets, developed for
electromagnetic-wave absorption and noise suppression, can eliminate noise effectively. EMC/EMI problems are solved by attaching noise-suppression sheets simply on the parts that are sources of noise.

Usage examples

Example 1: Wrapped around a cable

Example 1: Wrapped around a cable

Example 2: Applied to a flat cable

Example 2: Applied to a flat cable

Example 3: Applied to an integrated circuit (IC) top

Example 3: Applied to an integrated circuit (IC) top

Example 4: Applied between integrated circuits

Example 4: Applied between integrated circuits

Example 5: Applied to case and between boards

Example 5: Applied to case and between boards

Features and advantages

• Very flexible and easy to handle
• Can be delivered in any shape, size and/or thickness
• Optionally available as a custom-made tube
• Can be cut according to the customer’s drawings
• Provides effective EMI suppression in a wide frequency range (1MHz to 18GHz)
• Changes the magnetic flux path to avoid interference with other components or surrounding cables
• Reduces the eddy current when the magnetic flux is close to metal
• Non-conductive adhesive backing (UL recognized) available
• Effective in preventing resonance and suppressing coupling
• High surface resistance (>10⁶ Ω)
• Easy and fast to process due to self-adhesive

Applications

• RFID (Radio Frequency Identification) systems
• NFC (Near-field communication)
• Wireless power chargers (WPC / Qi)
• Computers (NB / desktop / tablet) and peripherals
• Digital Products
• Mobile phones / smartphones / phablet
• Wireless equipment
• EMI-shielding box / black box
• Between printed circuit boards
• On IC’s, processors, and controllers
• On cables that need high flexibility

Material structure

Choosing the right EMI flexible absorber sheet

Permeability ( µ = µ’ – j µ’’ )

 The variation of response frequency when RFID tag + 5780 + metal (Reference)

The response frequency is become lower when 5780 thickness become thick but the signal strength with little difference.

The response frequency is increase when metal attached, but the signal strength is smaller if the 5780 thickness is thinner. It means the metal affect more when the 5780 is thinner.

Effect diagram - Magnetic shield

5780 EMI flexible absorber sheets can change the magnetic flux path to keep the magnetic flux from affecting other components.

Effect diagram - RFID/NFC on metal

The magnetic flux induced an eddy current and generated a reverse magnetic field to offset the
magnetic flux to cancel the communication. After attaching an EMI absorber sheet between the metal and the RFID
antenna, the communication recovered.

Effect diagram - Wireless power charger

5780 EMI Flexible absorber sheets can be used for a wireless power charger to avoid eddy current when the RX coil is attached to metal; this changes the magnetic flux path between TX coil, RX coil, and magnet.

Filter Effect Test

Magnetic Shield / Decoupling Effect Test

Insertion loss (1MHz ~ 3GHz)

Return loss (1MHz ~ 3GHz)

Return loss (3GHz ~ 18GHz)