Homebrew PCBs

John,
I found that if I had the toner looking thin (sort of speckled) on 
the transparency (you can only tell with a good magnifier like my 
30X one), that after ironing (with a lot of pressure) that it filled 
in nicely on the board (as seen in the microscope) and didn't widen 
too much. I will confess that at times, I still make the traces a 
little narrower than the desired width, knowing they will widen. I 
certainly didn't want to feel it bumped up on the paper, although I 
started out with exactly that idea too.

BUT, what may work well is to not worry about the thickness but NOT 
apply too much pressure (someone mentioned that yesterday), but the 
problem with this is that if you are ironing by hand, the pressure 
is so subjective. One might get it perfect one time and not the next.

I have yet to try a double-sided board but I need to sometime. It 
would shorten the routing step considerably. I have had some board 
where I had quite a few jumpers to be able to get all the traces on 
one side. Thanks for the tips.

My biggest problem is that my PC board making comes in spurts. I may 
make 2 or 3 in a month and then go several months before I make 
another. I have to relearn too much each time.

--- In Homebrew_PCBs@yahoogroups.com, whoop@b... wrote:
> 
> Kenny, I upped the toner density to make sure I got a solid black  
> print (I have a software utility to do that on my Apple 
Laserwriter).
> 
> I get a good solid black I can feel with my fingers is raised, but 
I  
> do tend to get small pad centre holes after ironing on, to the 
point  
> of the hole disappearing at times, so I think your idea of going 
the  
> other way and using less toner may be good. I am using a 
Staedtler  
> Lumocolor pen to touch up any little bits that need it. I am 
using  
> the black pen 318-9 and it works. I have read that the only one 
to  
> use is the red version of the pen, but black seems OK to me.
> 
> All laser printers print heavier than they should. I often see  
> printouts that come out of a 600 dpi laser side by side with 
output  
> from a 1270 dpi or 2540 dpi Linotron typesetter and the difference 
is  
> huge.
> 
> I did my first double-sided board 2 days ago (yes another clock, 
but  
> much smaller) and it seemed to work OK. I drilled four holes in 
the  
> corners and lined up the second side with the holes. I got it a 
bit  
> out of true, but not enough that the board was useless. I had no  
> trouble ironing on one side and then doing the other. I had 
imagined  
> the back might re-melt and smear.
> 
> John
>