Homebrew PCBs

Brian Pitt wrote:
> if the attachment comes thru its of a laser printing onto copper foil
> about 1/2 of it got toner to stick and a few spots the toner stuck then 
> peeled back off and a few other places hardly got any at all
> 
> there might be some tricks to get better results but a quicky
> experement didnt turn out as well as expected YMMV
> 
> Brian

   Still, that is impressively good for just a simple straight shot at it. 
Solid prints should be well within striking distance with a little work from 
that good of a starting point.

   I'm still thinking an oxide layer would be the best thing to try.  Simple to 
make, less conductive, tend to be more 'sticky' than bare metal, and unlike most 
coatings etc the copper oxide will still etch easily.  Just the brown like old 
PCB or a penny not the true green stuff of course..

   And that turned out way better than I'd have expected for just bare copper, 
all things considered.  Looks like print density might even fix it, I'm assuming 
you had the 'Black' checked off in Eagle but make sure it's also set highest in 
your print driver too, some will interfere.  We're going to be screwing up the 
printers for normal use anyway, even if it took a simple mod to make the printer 
print 'super black' beyond what it's normal settings could do it'd still be well 
worth it.  I'll take a look at what that takes, I've always assumed it's just 
higher charging voltage to attract more toner etc but could be done in other 
ways.  It may just be a set charging voltage then the laser just partially 
discharges even the black areas too.  Simply upping the high voltage a bit may 
be all it takes.

Alan