Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, DJ Delorie <dj@...> wrote:
>
> 
> "Jim Miller" <jim@...> writes:
> > I've gotten some breakout boards in the past from Sparkfun that
> > worked well for SOIC but I now need a few for a uSOIC which has
> > 0.5mm lead pitch for 10 pins (or more.)
> 
> These are the types of boards I'm most likely to make at home.  Just
> design one, put four to six copies on a small panel, and etch them.
> Choose the best resulting board.  I use resistor lead trimmings for
> "legs" (they're smaller than 0.025" sq posts).
> 
> 0.5mm pitch is only 10 mil rules, you should be able to do that at
> home.
>

I agree with DJ - Do a panel of them to make sure you get a good one 
if you are not always doing stuff that small.

I have just done a 0.45mm QFN package (ATMega48) and the resist came 
out good.  The etch is what I had a problem with.  I panelised 15 
boards to make sure I got a good one.  

Some tracks (6-8 thou) almost got etched completly away on one side 
of the panel before the other side was clear of copper.

I guess it is dinfitly a case of some people have got bubble etchers 
that work well and mine is crap :D

I think I am going to keep a tub of Ferric Chloride around just to do 
these fine ones and float etch them till I get a spray happening.