I would be interested in hearing other BGA routing strategies.

Barbra

> -----Original Message-----
> From: Jon R. DeGenova [SMTP:[log in to unmask]]
> Sent: Wednesday, May 13, 1998 2:01 PM
> To:   [log in to unmask]
> Subject:      Re: [DC] Minimum routing layers for a 256 pin BGA part with
>
>      Pat,
>
>      We divide the part into the four quadrants, and in each quadrant
>      fan toward the corner of the part.  This makes for a horizontal
>      and a vertical routing channel (like a plus sign) through the
>      center of the part.
>
>      Jon DeGenova
>      [log in to unmask]
>
>
> ______________________________ Reply Separator
> _________________________________
> Subject: [DC] Minimum routing layers for a 256 pin BGA part with 1.27
> Author:  "DesignerCouncil E-Mail Forum." <[log in to unmask]>,
> Pat
> Paulson <[log in to unmask]> at Internet
> Date:    5/13/98 11:59 AM
>
>
> I'm working on my first design using a BGA part and I'm looking for any
> ideas that would be helpful.  I'm using a 25 mil pad for the solder ball
> with pin escapes (through hole vias) for each pad. These pin escapes are
> placed in the same direction so the solder side of the pcb looks like the
> bga footprint for de-bug purposes.
>
> I guess this means I have to use 4 layers to route away from the part? Are
> there any tricks that I'm missing? I'm ready to say the heck with pin
> escapes at the part.  What techniques do other people use?  I'm using 6/6
> widths/spacing.
>
> Thank you for your ideas/help!
>
> Pat Paulson
> VTEL Corp.
> [log in to unmask]
>
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