Re: gEDA-user: A couple o' questions

[Marvin Dickens <marvindickens@xxxxxxxxxxxxx>]

Stuart Brorson wrote:
> > Is it a DRC failure? I have my boards full of such shit and I don't
> > care. I think the 1mil wide think cannot peel off and float because it's
> > held on both ends. Maybe it can get interrupted but I don't rely with
> > my groundplane connectivity on such thin places.
> >     
>
> This should be a failure.  A 1 mil trace can easily become a 0 mil
> trace at your PCB fab house due to their tolerances.  That is, the
> etch process used to etch out your traces has variability; if you have
> 1 mil features on your board, they might be totally eaten away during
> PCB manufacture. 

Both bridging of closely spaced traces and total removal of traces is 
caused by the puddling
of etchant during the etching process. Inverting spray etching machines 
are less likely to
produce this problem. The cons  of inverted etching machines include 
that they can only
etch one side of a board at a time.  even so, the pros weigh the cons...


Best


Marvin