Homebrew PCBs

On Tue, 10 Apr 2007 16:07:01 +0200, derekhawkins <eldata@...> wrote:

> 8/8 rules on a reliable basis should be easy with the crudest of
> etching setups provided you can see the process and not just depend on
> a timer. Etching has always been the no-brainer step for me.
> It's the printer and/or transparent media that's the limitation at
> finer rules (below 6/6) IMO. A combination of irregular spacing and
> rough edges in the case of inkjet or toner fuzz in the case of laser
> seems to be the show stopper. Magnification of the artwork is all
> that's required to confirm this.


I'm not actually sure about that. I've transferred finer lines with TT  
that looked ok, but they disappeared completely during etching.
I do not know what the under-cutting rate is, but let's keep in mind 35u  
is 1.4mil, and it looks always like areas close to resist etch faster than  
large copper areas. So i would not be surprised if there is quite some  
undercut.


Anyway, even the pro board houses have 5/5 as their "standard" product.  
Some even 8/8...


ST