Halcyon Audio Labs had a wireless speaker module that sounded great and radiated too much RF. Two weeks before their pre-compliance scan, they were over the FCC Part 15 limit in a band they couldn't afford to fail, and a board respin would have blown the launch window.
Great product, failing scan
Halcyon is a ten-person hardware startup building a premium wireless speaker. Their radio and amplifier share a compact board, and in early EMC testing the switching regulator and the RF front end were coupling enough energy to push them over the radiated-emissions limit.
The clean fix — a full board redesign with more ground stitching — existed, but it was six weeks and a new fab spin they didn't have. They needed to contain the emissions at the source instead.
Shielding, but it has to be manufacturable
Board-level shielding is the standard answer: a metal fence soldered to the ground plane over the noisy section, with a lid that snaps on. The catch is that a shield only works if it seats flat, makes continuous ground contact, and can be soldered by the same reflow process as everything else on the board.
A hand-bent prototype shield got Halcyon close in the lab, but it wasn't repeatable — every one seated slightly differently. They needed a production part.
The part we built
We stamped the shield frame from 0.5mm nickel silver with a bright tin plate so it solders cleanly in reflow, and held the footprint to ±0.08mm so it registers to the pads every time. The frame includes formed spring fingers along the perimeter for continuous ground contact and a positive-retention lip for the lid.
Nickel silver gives good shielding effectiveness and stays dimensionally stable through the solder cycle, and the tight tolerance means the pick-and-place machine and the reflow oven treat it like any other component.
First-pass compliance
With the shield populated, Halcyon's next radiated-emissions scan came in under the limit with margin to spare — on the first attempt, no respin. The consistent stamped footprint meant their contract assembler could place and reflow the shields with zero hand-fitting.
They hit their launch date. For a startup where the launch window and the compliance test were the two hardest gates, a precision stamped part cleared both at once.
“We were staring down a six-week respin. The shield bought us the margin and we made our ship date. That part saved the launch.”
Priya Nair, Hardware Lead, Halcyon Audio Labs