March 1 Tariffs: What Actually Changed

The tariff does not read your BOM. It reads the country-of-origin field on the commercial invoice — one line of text that now carries a 25% multiplier.

The 25% tariff on Korean-origin electronics is active and enforced. What changed in practice:

Customs is flagging it. US customs brokers are flagging Korean-origin HTS codes; cargo has seen 48-hour holds at Long Beach and LAX for origin verification.
Distributor pricing lags. Distributor catalog prices have not fully adjusted — inventory landed before March 1 is pre-tariff. New inventory arriving after will carry the surcharge. The price you see today is not the price you will pay on the reorder.
Vietnam routing works. Korean manufacturers with Vietnamese production are documenting Vietnam origin; this adds 1–2 days of clearance but avoids the 25%.

What did not change: raw material imported from Korea and substantially transformed in the US remains exempt. Substantial transformation is the legal test — a change in name, character, or use. Stamping and forming a Korean coil into a finished shield in Vietnam is substantial transformation; relabeling is not.

POCONS response: Our shield-can production runs in our Vietnam facility — same standards, same tooling, unchanged lead times, Vietnam country of origin.

Korean Manufacturer Spotlight: Innox Advanced Materials (이녹스첨단소재)

Innox Advanced Materials, headquartered in Seongnam, Korea, manufactures flexible copper-clad laminate (FCCL) and controls roughly 25% of the global FCCL market. FCCL is the base material of every flex circuit — the foldable substrate in phones and wearables, and the flex harnesses in automotive.

Their technical edge is low-loss FCCL grades for impedance-controlled, high-frequency flex up to 28 GHz — the band that matters for 5G mmWave antenna feeds and high-speed board-to-board interconnect. Loss in a flex laminate is governed by the dielectric loss tangent (tan δ) and conductor surface roughness; at 28 GHz, skin depth in copper is only ~0.4 µm, so the laminate-copper interface roughness directly sets insertion loss. Low-loss FCCL uses smoother copper foil and a low-tan-δ polyimide or modified-PI dielectric.

POCONS connection: A shield design has to account for flex-cable routing. When a flex circuit exits a shielded compartment, the cable aperture and the FCCL's own ground structure determine whether the shield seam stays sealed. We design can apertures and gasket interfaces around the actual FCCL geometry — the cable is part of the EMI boundary, not an afterthought.

Price Watch

🚫Tin Alert

Tin has broken $51,600/t. Myanmar's Wa State mining suspension — in effect since January — has removed roughly 10% of global tin ore supply. LME and Shanghai tin inventories are below 2022 lows. If Wa State operations do not restart, further upside is plausible. Tin is 96.5% of SAC305 solder and a primary shield-plating finish — this is a direct, unavoidable BOM cost for every reflowed board.

Bench Note

A customer's Korean-origin shield cans were held at Long Beach for origin verification, threatening a production deadline. A Vietnam-sourced equivalent — same alloy, same dimensions, same plating spec — cleared customs in 4 hours and the line ran on schedule. The cans were electrically identical. The only thing that differed was the country-of-origin stamp, and in 2026 that stamp is a schedule risk, not a footnote.

One Thing

The tariff doesn't care about your BOM. It cares about the country-of-origin stamp on the commercial invoice. Two electrically identical shields, one stamped Korea and one stamped Vietnam, now differ in landed cost by 25%.

— From our factory floor