Plastic layer between PCB and case?

[maroder]

Hi,

I just received my second aluminium CNC case. There is a thin piece of plastic inlay in the case, I guess to protect the PCB from the aluminium seatings. I much would prefer to remove the plastic and seat the PCB directly onto the CNC aluminium, as the keyboard would then sit completely flush within the case.

Will this harm the PCB or is the plastic just a precaution for installation?
Anyone got an idea?

[Parak]

Aluminum is conductive. Any exposed point on the PCB that comes into contact with it will be shorted with other contact points. This is a bad.

[jbondeson]

You could also put a thin non-conductive (plastic) washer between the standoffs and the pcb.

Out of curiosity, what case is this?

[ika]

Aluminum is conductive. Any exposed point on the PCB that comes into contact with it will be shorted with other contact points. This is a bad.

Regular anodized aluminum should not be conductive, although conductive anodizing exists. Check with a multimeter first.

[heedpantsnow]

I always put something in my alu keyboard cases.  Always.  A piece of foam shelf liner, Tyvek, or the really thin foam bags that LCD's come wrapped in.  Why take the risk?  Sure, some anodizing is non-conductive, but your solder joints can/frequently do scratch through.

[platypus]

+1 for drawer liner, if you don't have any laying around, you can get it on amazon, or at a dollarama, target, walmart, home depot, etc.

It also reduces "ping" and resonance similar to placing your keyboard on a mat.

[maroder]

Thanks for the replies. Its a Pexon CNC case. I will just put some drawer liner in between.

[jd29]

How about some short standoffs? I don't know if you want the PCB as low as possible, or dislike the plastic for some other reason.

The highest contact points on your PCB are probably the switch pins, so I doubt setting it on the aluminum would destroy anything but your keyboard definitely won't work.