Ensuring contact between aluminum chassie and EMC fingers

[ThomHM]

Hi, I'm a senior electronic engineer who also dabbles a bit with mechanics. I need some advice as my knowledge in this area
is limited.

I have a housing made of cast aluminum and a PCB inside with two combined RJ45/USB connectors that protrudes through square holes in the housing. These holes have
machined/milled edges and the connectors have spring-like "fingers" that presses against the hole edges to drain off EMI into the chassis. These fingers are cut and
formed from the connector casing itself and is likely made of nickel/bronze.

My thoughts are that aluminum eventually oxidizes and the milled surface become insulating and therefore will not drain away the EMI. To hope for an initial gas tight
connection is not realistic as this unit will live in a vibration environment.

Is there a way to treat the alu egdes somehow to ensure lasting connection between the two metal surfaces?

Thanks in advance and best regards
/Thom

 

[3DDave]

Electroless nickel plating is the typical answer.

 

[ThomHM]

Ok, thank you Dave. I'll look into it.

/Thom