Circuits Assembly Online Magazine - Precision MicroOffers ‘Quiet Corners’ to Improve Shielding Attenuation

The effectiveness of board level EMI/RFI shielding depends on many factors: the design of the shielding can, material choice, thickness, venting, method of attachment and the ‘maximum linear dimension’ (the longest contiguous hole or slot). This maximum opening size is a function of the frequency spectrum of the device being shielded and of the attenuation you are trying to achieve.

Profiled and folded shielding cans offer many benefits, including bespoke design, exceptional co-planarity, low tooling costs etc., but one drawbacks is the corner seam, which can act as an emitter antenna if it is not folded and mounted with care. This corner seam can be soldered for complete integrity in high frequency applications but much of the time, the need is simply to reduce the maximum linear dimension.

A new finger joint arrangement on the corner seam allows two adjacent walls to interlock along the corner seam.

The Quiet Corner design reportedly improves noise attenuation and the mechanical stability of the shielding can.