High Permeability Ultra-Thin Magnetic Shielding Sheets for NFC Applications

TDK Corporation extends its Flexield family of magnetic shielding materials with the introduction of the IFQ06, offering high permeability (μ’) and low magnetic loss (μ”) designed for near-field communications (NFC) applications.

The IFQ06 material protects highly effectively against performance-reducing design features that complicate NFC designs, such as metal objects directly behind the antenna.

With the evolution of ever smaller and more multifunctional electronic devices, it is increasingly difficult to keep advanced functionalities from interfering with each other. NFC communication uses electromagnetic induction where the antenna receiving a carrier wave from a reader/writer allows the onboard IC chip to perform signal processing.

Metal objects, in particular, can absorb or disturb the magnetic flux lines of the generated H field, creating eddy currents which reduce effective range. These disturbances can also shift the inductance value and self-resonance frequency, reducing performance because of tuning issues between the two antennas. In some cases, metal close to the antenna will carry an induced current that produces a countering magnetic field, shortening the communication distance and making communication impossible.

By placing the newly released IFQ06 series material between the antenna coil and any metal surface, the magnetic flux is confined within the magnetic shield generated by the reader/writer. As a result, the generation of an induced current on the metal surface is eliminated, and optimum 13.56 MHz communication conditions can be maintained.

Other benefits of the IFQ06 series include the following:

• Shaping/directing the magnetic H field
• Influencing the quality factor (Q) of the inductive antenna
• Increasing the coupling factor (K) between the two antennas
• Helping set the inductance value (Ls) for resonant tuning
• Completing the magnetic field path
• Improving security by encapsulating the magnetic field and its respective information

TDK’s IFQ06 flexible magnetic sheet materials are offered in three formats: roll or sheet materials ideal for prototyping, lower volumes or where large areas need to be covered, and custom-cut parts to match design requirements for higher volume or automated assembly options.

Features

• Highly flexible magnetic material that facilitates easy forming to desired sizes and shapes
• Available in multiple standard thicknesses: 0.050 mm, 0.100 mm, and 0.200 mm
• Additional thicknesses of 0.065 mm and 0.075 mm are available upon request
• High permeability for thin film (µ’: 56), low magnetic loss (µ”: ~ 2) and good Q [µ’/µ”: 28] at 13.56 MHz
• High surface resistivity of >10 MOhm allowing for direct contact with metal antennas
• Available with an optional high-temperature resin [IFQ06S] that supports applications up to +125 °C
• Available on a roll, in sheet format, or customized to the customer’s specific needs