Re: gEDA-user: PCB suggestion

[Karel Kulhavy <clock@xxxxxxxxxxxxx>]

On Fri, Jan 07, 2005 at 05:58:10AM -0500, Bob Paddock wrote:
> On Friday 07 January 2005 01:57 am, Stephen Meier wrote:
> > I feal like I have to step in here. With a 900 pin BGA (30 rows by 30
> > columns) at a 1mm (39 mil) pitch. Four signal layers are just bearly
> > able to route all the signals out from under the bga. That was using via
> > in pad and squeezing two 4 mil traces between pads/layer. 
> 
> I know you can not post the design, but could you post the section relevant to 
> the BGA?  I'd like to know how to do these large BGA's myself.
> 
> Via "via in pad" does that mean each ball falls into a via, or are the balls 
> on non-hole pads?

Is putting vias through SMD pads a bad practice? Can it influence reliability
of the soldering?

Cl<