A custom EMI/RF shield can only delivers its 40-60 dB isolation when it is mounted as a continuous Faraday cage grounded to the PCB perimeter with no skipped pads, no rocking, no spring-tab gap. Gleamco (Dongguan Yaotai Metal & Electronics Co., Ltd.) stamps board-level shielding covers in nickel silver, tinplate (SPTE), brass, stainless steel, and beryllium copper at +/-0.01 mm, but field EMC failure is usually an installation issue, not a stamping issue.

1. Pre-installation check
– Verify the shield footprint matches the stamped can: outer dimension, wall height (2-5 mm typical), ground-tab pitch, vent/slot position.
– Confirm PCB ground pad ring is continuous, connected to inner ground plane by dense via stitching (via pitch <= lambda/20 at target frequency).
– Keep >=0.5 mm clearance from tall components (connectors, coils, electrolytic caps) to avoid coil contact or lid deformation.
– Clean pad area with IPA; remove oxide on bare copper; no fingerprint oil on tinned rim.

2. SMT reflow soldering (best shielding, permanent)
Used for one-piece cans or two-piece shield fence (lid is separate).
– Stencil: 1:1 aperture on perimeter pads, reduce center-pad aperture 10-20 % to control solder volume; use solder-mask-defined pads to stop bridging.
– Paste: SAC305 or SnPb per profile; print thickness 0.10-0.15 mm.
– Placement: pick-and-place for small cans (<20×20 mm); laser-aligned manual fixture for large cans.
– Reflow: standard SMT profile; shield mass can cause tombstoning if center pad heats slower use thermal relief spokes on center pads and profile the can corner with a thermocouple.
– Accept criteria: 100 % perimeter wetting, no solder ball on vent holes, lid sits flush, no coplanarity rock.

3. Clip-on / snap-fit shield (rework-friendly)
Spring tabs on the can snap into PCB slots or onto SMT shield clips (tape-and-reel, placed by pick-and-place).
– Lower SE than solder (contact is discrete, not continuous) but acceptable for 30-50 dB class consumer RF.
– Do not over-bend tabs during removal; tab fatigue reduces normal force after 3-5 open/close cycles.
– Use when firmware/RF tuning needs lid-off access post-assembly.

4. Two-piece shield (fence soldered + lid clip-on)
Most common automotive/telecom choice:
– Fence = permanently reflow-soldered to PCB, continuous ground, max SE.
– Lid = snap-on over fence with finger springs, removable for debug, no desoldering.
– Gleamco supplies fence + lid as matched set: dimples, finger count, and insertion force tuned to your lid thickness (0.2-0.3 mm).

5. Press-fit and screw-fixed (rare on PCB)
– Press-fit posts into plated holes: no heat, moderate SE, risks pad crack if PCB flexes.
– Screw fixing: only for large module cans, needs EMI washer under screw head.

6. Common installation defects
Tombstoning caused by center pad heat sink effect; fix with thermal relief + stencil cut.
Cold joint on one side caused by board warp or poor coplanarity; fix by flattening PCB and checking can flatness within +/-0.05 mm.
EMI leak caused by skipped ground pad or gap >0.1 mm; fix with 100 % AOI on perimeter.
Lid rattles caused by tab spring force too low; fix by specifying BeCu finger instead of tinplate.
Solder balls in vents caused by excess paste; fix by aperture reduction + wipe.

Why Gleamco shields install cleanly
– Progressive-die stamping gives burr <=0.03 mm, no rocking edge.
– DFM review aligns tab pitch, vent size, and fence/lid engagement to your PCB layout before tooling.
– Materials: nickel silver (solderable, stable), tinplate (cost), BeCu (spring fingers), brass (conductivity), SUS (rigidity).
– 7-8 day prototype, IATF 16949 / ISO 9001, RoHS, tape-and-reel or blister pack for SMT lines.

A shield can is a grounded enclosure, not a metal cap. Correct pad design + right mounting method + stamped accuracy = passing FCC/CE radiated test on first spin.

 

inquiry@gleamco.com | https://gleamco.com/rf-emi-shield/