--- 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.