Auto route

[Angelo Fraietta]

I am looking for an academic reference for the pro and cons of auto routing with
a tool like Protel.

Does anybody have any references that I might be able to use?
--
Angelo Fraietta
Home Page
http://www.users.bigpond.com/angelo_f/

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[David Harmon]

I am looking for an academic reference for the pro and cons of auto routing with
a tool like Protel.

Does anybody have any references that I might be able to use?

What are you trying to accomplish?

 

[Simon Peacock]

The pros are a cheap auto-router may generate a board.. the cons are they
may generate a board.

I've been designing PCBs for over 10 years and the cheap ones are just that
... cheap unless you have a spear $100k then your better off setting the
rules and routing it by hand... and even if you have $100k .. it'll still
take you longer to setup the design rules than to hand route

but that's my opinion.

Sometimes you get lucky and the router will finish .. but I've hand cleaned
a PCB in as much time as it took for me to route it by hand for the next
rev.

Simon

 

[Angelo Fraietta]

What are you trying to accomplish?

I am writing a thesis and am justifying the use of auto routing in Protel

I found one
Feldmann, K., M. Koch, and A. Rothhaupt. "Intelligent Enhancements for
Conventional Layout Systems to Support the Design of Printed Circuit Boards."
Paper presented at "Low-Cost Manufacturing Technologies for Tomorrow's Global
Economy," Proceedings 1994 IEMT Symposium., Sixteenth IEEE/CPMT International,
12-14 September 1994 1994

--
Angelo Fraietta
Home Page
http://www.users.bigpond.com/angelo_f/

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[Angelo Fraietta]

The pros are a cheap auto-router may generate a board.. the cons are they
may generate a board.

I've been designing PCBs for over 10 years and the cheap ones are just that
.. cheap unless you have a spear $100k then your better off setting the
rules and routing it by hand... and even if you have $100k .. it'll still
take you longer to setup the design rules than to hand route

but that's my opinion.

I found Protel 99SE was quite good. But then again, I don't have the experience
of hand routing that you have.

Sometimes you get lucky and the router will finish .. but I've hand cleaned
a PCB in as much time as it took for me to route it by hand for the next
rev.

I sometimes had that problem.

Simon
Thanks.

--
Angelo Fraietta
Home Page
http://www.users.bigpond.com/angelo_f/

Note:Remove NoSPAM to email me

 

[Hal Murray]

I am writing a thesis and am justifying the use of auto routing in Protel

Nothing to do with Protel, but in general...

Look at the big picture. It's a cost/benefit issue.

If the auto router works on your problem it will probably save you
a lot of time.

I expect that many large/complicated designs are mostly auto routed.
I also expect that there is a lot of hand work in critical places.
Most of the time the auto-router will do the right thing if the placement
is good and the remaining choices are pretty simple. Often you can give
it hints/constraints to help it do the right thing.

The last board I did was tiny and simple. The auto router did it in
a few seconds. I pushed some parts around to make the job simpler.
The next try it got a better result. I'm sure I could have done
a better job by hand, but it wasn't worth the time/effort.

 

[[email protected]]

The pros are a cheap auto-router may generate a board.. the cons are they
may generate a board.

I've been designing PCBs for over 10 years and the cheap ones are just that
.. cheap unless you have a spear $100k then your better off setting the
rules and routing it by hand... and even if you have $100k .. it'll still
take you longer to setup the design rules than to hand route

but that's my opinion.

Sometimes you get lucky and the router will finish .. but I've hand cleaned
a PCB in as much time as it took for me to route it by hand for the next
rev.

Simon

Generally agree, though on boards containing many bussed components
auto-routers often do a good job of laying in the endless parallel
tracks and can save a lot of time here.

Where auto-routing is always useful is in testing component layout.
Run the autorouter (not necessarily until it has finished trying)
and look at the failed routes. Congested area, mis-alignments,
long traces on critical signals should all become apparent and
suggest how the layout could be improved. A few times round this
loop generally finds a better layout whether auto or manually
routing the final PCB.

 

[news.sonic.net]

I've used Protel 99SE to autoroute some very complicated boards and had good
success. I've just had to put some forethought into what I wanted out of the
route and had no troubles.
CW