Yahoo Groups archive

Homebrew PCBs

Index last updated: 2026-04-28 23:05 UTC

Message

Re:Double to single sided board

2009-01-14 by Lee Studley

You could paint the unused side with clear lacquer or polyurethane, etch 
the trace side, then
make an isolation drill bit. Where ever you need a through-hole item, 
drill the hole from the trace side, then on the
other lacquered side use the isolation bit to scrape/make a pad on the 
other side.
 
This way the lacquered side can also be a big ground plane and wont need 
to be etched away, wasting etchant.

2 ways to make a isolation bit:
1) if you are good with a dremel, use a disc or grinding bit and grind 
the tip of a spare drill bit so that the cutting edge is slightly a W
with the center able to go into the tiny hole, and the outer W legs able 
to cut the pad. Be careful or it will cut all the way thru.

2) Use a large enough drill bit that can be centered in the hole, but 
the V of the cutting edges is wide enough to give about a 1/16" or 1.5mm
wide insulating crater in the the PCB. Turn the drill bit by hand or 
carefully in a drill press.
-Lee

Attachments

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.