Homebrew PCBs

In a message dated 06-Dec-01 17:55:59 Central Standard Time, victorf@... 
writes:


> how about just buying a thin copper sheet say 3mil or so.
> then run the copper through the laser printer and print your art work.
> once that's done laminate the copper to a fiberglass board.
> then etch as normal.
> would this work????
> does anyone see any problems with this?
> 

Vic:  First question:  NO.  Second question:  YES!  This would be akin to 
training dolfins to fly.  Even if you could get the toner to stick to the 
copper, it ROLLS in there, and would crumble.  And, laminating it to FR-4 
requires HEAT and PRESSURE, and there wouldn't even be consecutive CRUMBS of 
toner left on the Cu!  If this was a "good idea", it'd be "perfected" and 
DONE, by now!  

There are TWO ways to do homebrew PCB's:  Use "rub-off" ("impression") 
patterns (Radio Shack sells NICE ones that work very well, if you keep your 
nasty fingers away from the "good side"!).  Etch.  Drill.  OR, if you have a 
"CNC method" to drill on a 0.05" grid, drill the holes first, sand (deburr), 
and THEN do the "rub-off thing".  

Second method, OK for really-simple little PCB's:  Use FINGERNAIL polish, and 
PAINT the pattern on.  Use an Xacto-knife to scrape-off or shape the sloppy 
work, etc.  OR, press-on 3/4" wide Scotch "Magic Mending Tape" (the "frosty" 
Scotch-tape stuff), and then CUT the pattern with that knife, peeling-off the 
unwanted part.  Then etch.  If you worked neatly, and didn't get greasy 
fingers all over the stickum-side of the tape, this will make a FINE etch!  

Also, for "one-off" double-sided boards, DRILLING first is necessary!  

See my PCB drill in FILES.

I do this so infrequently that I just use warmed Ferric Chloride (the nasty 
yellow-brown stuff).  I once got some Ammonium Persulfate from one of those 
mail-order places in the back of the magazines, but I could never get that to 
work right, and it left a ruined cabinet and carpet, where it "came through" 
the factory-container after a year!  

If you need more than three of "same board", get 'em done  PROFESSIONALLY!  
Unless you are very, very poor, and on house-arrest, so "have the time".  
NOTHING beats a plated-through board for soldering leads in place!  Wicking!  
Strong!  Excellent!  Lotsa luck!   Jan Rowland