Re: Who's using autorouters for their designs?

From: Mac (foo_at_bar.net)
Date: 10/23/04 

Date: Sat, 23 Oct 2004 17:27:07 GMT

On Fri, 22 Oct 2004 19:39:24 +0200, Henk Boonsma wrote:

> I'm wondering how many people are using autorouters for their board layouts
> and in what percentage (i.e. what percentage is being routed by the
> autorouter)? I've had some bad experience using autorouters and hardly use
> them anymore. OTOH, Electra claims that autorouters do a very decent job
> with digital circuits and that even though the layout doesn't look as
> 'artistic' as one done by a human, they are ussually better.
>
> When I look at board layouts on most digital products (e.g. motherboards) it
> seems to me that they've been done manually (i.e. most signal busses are
> perfectly routed next to each other, something an autorouter won't ussually
> do).
>
> What do you guys think?

I used to work for a well-known large company that designed single board
computers (using the high-end Mentor Graphics tools) for telecom
applications. We did not use an autorouter at all.

However, a friend of mine tells me that people who really know how to use
autorouters can get good results. He used to work with one of these guys.
The guy now works (on a contract basis) for a large, US-based PC company
and sets up the autorouter to do their motherboards for them. I don't know
what tools they use.

I guess the trick is finding the right balance so that you meet skew and
signal integrity guidelines, but don't over-constrain the board.

--Mac