Stefan,
Mariss Friemanis of Gecko drives mentioned some good information
about how he lays out his SMD VERY densely populated drives. It
involved some "strange" values for the layout grid, and included soem
thought about where to run vias and ancillary parts...
Un fortunately, I'm not sure where I filed it. But he's known to be
quite helpful, and hangs out at several groups including the
electronics 101 group that I think belongs to our list owner here?
Anyways, I'd call him, or at least ask on a user group where he's
evident. It was VERY good info, and of the type borne of hard-won
empirical experience, not book learning...
Hope this helps,
Ballendo
--- In
Homebrew_PCBs@yahoogroups.com, Stefan Trethan
<stefan_trethan@g...> wrote:
> Hi,
>
> i was wondering if there is a tutorial for advanced routing.
> I mean as soon as you have two layers and more than 100components
> it starts to get more difficult.
> If there is no tutorial we could maybe exchange some tricks.
>
> How do you start?
> How do you decide which parts are on which side?
> (i put the SMD ones on top which can be connected to throughhole
without
> adding a via, and i aim for the same population density top and
bottom.)
>
> Often it is required to rotate and rearrange parts to get a good
layout,
> but at a certain number of parts it is very hard to keep track of
things.
>
> Do you start routing with special nets, like supply?
>
> You see, the methods i used for years on smaller circuits seem
very, very
> hard
> to apply to bigger circuits, and i believe there must be some
tricks i
> don't
> know yet.
> Maybe if everyone throws in a few ideas we can all learn something.
>
> I always use different color "rubber bands" for GND and VCC which
helps a
> bit.
>
> ST