If you could use a non-drilling method of mounting you might be better
off. I suggest some sort of bracket that holds the PCB by the edges.
Cruise the catalogs. One idea that you might try is to get some nylon
screws and nuts. If you are mounting to a base plate, drill four holes
in the base plate at the periphery of the board. You want the screws to
just clear the PCB. Pop in the screw and fasten with one nut. Add
another nut up the screw a ways; the PCB will sit on this nut. Add one
more nut to sit on top of the PCB and clamp down on the bottom nut. (No,
I havn't actually tried this...)
Otherwise, any place that you don't drill through a trace is OK. Maybe
try nylon screws? 4-40 is plenty big enough and only needs a .125 hole.
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___________________
John Blacet
Blacet Research
http://www.blacet.com