How much copper is safe in a PCB faceplate?

[kylewetton]

I have some faceplates I laid out in the mail and I’m getting in my head about a couple of things.

I left the through holes for the pots plated, (figured it was durable), and used a copper pour on the top of the faceplate (manufacturer has previously left clamp marks on my faceplates without it), so again wanting to make it durable.

Now I’m starting to think, none of this copper is grounded and my potentiometer nuts will likely make contact with the copper plates in the holes.

My bare enclosure will also likely make small amounts of contact with the bottom of these plated holes.

Am I overthinking all of this? I’m worried I pretty much made an antenna somehow

 

[Robert]

Folks use aluminum faceplates.

I don't specify a ground plane in any of my faceplates but I've noticed visible copper in the drilled holes on a few occasions.

It's possible JLCPCB might randomly decide to leave the copper layer intact since it's being produced on a larger panel with other PCBs that most likely do require copper, cutting down the waste from removal when it isn't necessary.

Purely speculative, but I've definitely gotten a solid copper pour when I didn't ask for one.

 

[kylewetton]

Did you notice any noise issues with them?

 

[Bricksnbeatles]

If the enclosure is grounded then the faceplate with wind up being grounded too, from contact with the pots (which themselves will be grounded by the enclosure)

 

[kylewetton]

If the enclosure is grounded then the faceplate with wind up being grounded too, from contact with the pots (which themselves will be grounded by the enclosure)

That’s the thing though, I don’t know that the pots are actually making connection to the enclosure, the holes are tight, but not that tight

 

[Bricksnbeatles]

That’s the thing though, I don’t know that the pots are actually making connection to the enclosure, the holes are tight, but not that tight

Are they not making a connection to the inside face of the enclosure? Not the threads. But the pot housing itself

 

[kylewetton]

Are they not making a connection to the inside face of the enclosure? Not the threads. But the pot housing itself

Yes, they are, good point!

 

[GAStan]

Using Star Washers will insure a good ground.

 

[samlevy0515]

It's smart to think about this stuff! Y
ou're not overthinking it—ungrounded copper pours can indeed act like antennas, potentially picking up noise and causing weird interference in your audio signals, especially since the pot nuts and the enclosure will be making contact with it. For your next revision, you could either remove the pour from those specific areas or tie the entire copper pour to the circuit ground. For now, you might be okay, but keep some insulating washers on hand to place under the pot nuts if you start hearing any unexpected hum or noise.