Nanocrystalline Sheet for Wireless Charging

Product Gallery

Ultra-Thin, Flexible, Die-Cut to Your Coil

Nanocrystalline alloy ribbon laminated to film and adhesive — the high-permeability layer for RX coils, FPC antennas and low-frequency EMI shielding.

XAK F-N nanocrystalline magnetic sheets, thin silvery ribbon stacked and gently curved beside a copper wireless charging coil

Exploded wireless charging receiver module: copper FPC coil, ultra-thin nanocrystalline sheet and battery stack

Wireless charging transmitter coil mounted on a ferrite sheet plate, macro view of the charging module cross-section

The Challenges

Where Ferrite Stops Fitting

Four reasons teams move a design from ferrite to nanocrystalline.

The stack-up ran out of Z-height

A watch, earbud or card-style RX has 0.3–0.5 mm behind the coil, not the 0.5–1 mm a ferrite plate wants. Nanocrystalline reaches the same inductance boost at a fraction of the thickness — 0.06 mm grades included.

The module runs hot under misalignment

Misaligned charging sends flux into the battery and housing as eddy-current heat. High-µ′ nanocrystalline confines that flux more effectively, and open industry testing reports roughly 7–8 °C lower temperature rise than ferrite at equal charging conditions — verify on your own module before relying on it.

The housing curves — the ferrite doesn't

Rigid ferrite plates crack or gap when bent into curved wearable housings. F-N is a flexible ribbon: it follows the radius and still die-cuts cleanly to outline.

One layer must couple and shield

Behind an RX coil you need flux concentration toward the TX and protection for the battery/PCB behind. F-N does both in a single thin layer — no separate shield plate in the stack.

Our Approach

From Coil Drawing to Working Samples

We validate the sheet against your operating point — Qi, Qi2 MPP, or a custom WPT frequency — before cutting.

1

Frequency confirmation

Qi 1.x spans 87–205 kHz; Qi2 MPP is fixed at 360 kHz (the older 127.7 kHz figure is outdated). We characterize F-N at your actual operating point, not at a generic test frequency.

2

Thickness vs. inductance, honestly

Thinner sheet, lower effective permeability in the assembly. We quote the expected coupling range for your thickness choice instead of promising the datasheet number at any thickness.

3

Die-cut to your outline

DXF in, kiss-cut sheets on release liner out — single-sided PSA standard; double-sided tape or bare sheet on request. Rolls for high-volume lamination processes.

4

Bench verification on your module

We ship samples of the recommended thickness plus one neighbor. Measure coupling and temperature rise on your real coil and housing — that's the specification that matters.

Product Data

F-N Series & the Ferrite Alternative

Typical values for selection reference — final thickness is confirmed against your coil and measurement results.

Property	XAK F-N Nanocrystalline	Ferrite Sheet (typical)
Permeability µ′	≈ 13,000 @ 100 kHz	100–150 @ 1 MHz
Saturation induction Bs	1.25 T	~0.3–0.5 T (Mn-Zn/Ni-Zn class)
Thickness	0.06–0.4 mm	0.05–1.0 mm (single layer)
Form	Flexible ribbon, rolls, die-cut (DXF)	Sintered plate or flexible polymer-bonded sheet
Temperature rise	Lower under misaligned charging (open industry testing: ~7–8 °C less than ferrite, equal conditions)	Baseline
Material cost	Higher	Lower — still the default for cost-driven builds
Best for	Slim RX, wearables, hot-running or curved modules, high coupling density	Standard TX/RX builds with comfortable Z-height and budget

Applications

Where F-N Earns Its Keep

The four application families behind most of our nanocrystalline projects.

Qi / Qi2 TX & RX modules

Smartphone and wearable charging where coupling density per millimeter matters. Validated at 87–205 kHz (Qi) and 360 kHz (Qi2 MPP) operating points.

FPC receiving coils

The thin FPC coils in watches, rings and TWS cases need a magnetic backing that bends with the flex and die-cuts to the coil outline. That's exactly the F-N format.

Smartphones, wearables & consumer electronics

Ultra-thin flux confinement behind coils and antennas in space-critical consumer assemblies — 0.06 mm grades for the tightest stacks.

EMI shielding & flux confinement

Communication devices that need low-frequency magnetic shielding or flux control without the weight and brittleness of ferrite plates.

Engineering Notes

Is F-N the Right Material for Your Problem?

The three-question decision we run before any quote.

Choose F-N when…

You need stronger wireless-charging coupling or coil-to-metal shielding in a very thin stack (0.06–0.4 mm)
The module runs hot under misalignment and flux confinement is the lever
The housing curves, or the outline is complex enough that a brittle plate fails in assembly

Choose something else when…

Cost leads and Z-height is comfortable → a standard ferrite sheet is the honest answer; we supply those too
The problem is high-frequency EMI noise (100 MHz–6 GHz) → that needs a lossy absorber, not a flux director — see our S-A series
Not sure? Send us your frequency and target — we confirm the right material before sampling, in writing

FAQ

Nanocrystalline Sheet Questions, Answered Directly

The questions engineers ask before moving a design from ferrite.

Nanocrystalline vs ferrite — when is the switch worth it?

Three triggers: you ran out of Z-height (F-N reaches the same inductance boost at a fraction of the thickness), the module overheats under misaligned charging (higher µ′ confines flux better; open industry testing reports ~7–8 °C lower temperature rise at equal conditions), or the housing curves and sintered ferrite cracks. If none of these apply and cost leads, stay with ferrite — we'd rather tell you that now than after a sample cycle.

What thickness should I choose for my RX coil?

Start from your mechanical gap and work up: 0.06–0.10 mm for the slimmest stacks (rings, cards, earbuds), 0.10–0.20 mm as the wearable sweet spot, 0.20–0.4 mm where coupling density leads. Thinner buys Z-height and costs some effective permeability — we quote the expected coupling range per thickness instead of promising the datasheet number at any thickness. Send the coil drawing and gap; we recommend a grade and ship two thicknesses for bench comparison.

Is F-N validated for Qi2 MPP at 360 kHz?

Yes — we characterize F-N at the Qi2 MPP operating point of 360 kHz (Qi 1.x spans 87–205 kHz; the older 127.7 kHz figure you may still see is outdated). Note that MPP alignment magnets sit closer to the coil, so flatness and thickness tolerance start to matter for coupling consistency — specify them on your drawing and we cut to them.

How do I get sheets in my coil's exact shape?

Send a DXF (or a dimensioned drawing) and we kiss-cut F-N on a release liner to your outline — single-sided PSA standard, double-sided tape or bare sheet on request. Rolls are available if you laminate in-house. Registration marks for pick-and-place can be added. Typical sample turnaround is days after the grade is confirmed.

Can F-N replace a Laird nanocrystalline sheet or TDK Flexield IFQ in my design?

Grade-wise, F-N's µ′ ≈ 13,000 @100 kHz puts it in the same class as leading nanocrystalline offerings, and we regularly support second-source qualification. But "same class" is not "drop-in": permeability curves, laminated thickness and adhesive systems differ by supplier. The right path is the one we always recommend — send your current part number and target inductance, we match the grade, send samples, and you verify on your own coil.

Start Your Nanocrystalline Project — What to Send Us

You don't need a finished specification. Send what you have — we'll confirm material and thickness with you.

📡

Operating frequency — Qi 87–205 kHz, Qi2 MPP 360 kHz, or your custom WPT frequency

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Coil outline — DXF or dimensions, plus TX coil if you have it

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Space budget — available thickness and gap behind the coil in mm

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Targets — inductance/coupling range and temperature-rise limit

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Quantities — sample needs and estimated annual volume

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Timeline — when you need samples for bench testing

Nanocrystalline Magnetic Sheets — High-µ′ Coupling for Slim Qi & Qi2 Designs