PCB Auto-routing software: Cadence Allegro / SPECCTRA
PCB Auto-routing software: Cadence Allegro / SPECCTRA
(OP)
Hello,
In the past, I've always hand-routed my boards in software from a netlist and rats-nest. Obviously, it's a tedious and horrible way to do it.
Now, I'm looking for a software package to do all that hard work for me. Up until now, I've been using Cadence's Orcad Capture/Layout to make schematics then translate them into boards.
Does anyone have any experience with Cadence's Orcad Allegro for automatically turning my netlists and parts into fully routed circuit boards? In a perfect world, I'd love to just define a bunch of parameters and DRC specifications then press a button for the process to begin. But, I know it's never that easy :)
So, what do you folks think about Orcad Allegro/SPECCTRA? Also, if not Orcad, what's your favourite PCB design studio?
Thanks,
deef
In the past, I've always hand-routed my boards in software from a netlist and rats-nest. Obviously, it's a tedious and horrible way to do it.
Now, I'm looking for a software package to do all that hard work for me. Up until now, I've been using Cadence's Orcad Capture/Layout to make schematics then translate them into boards.
Does anyone have any experience with Cadence's Orcad Allegro for automatically turning my netlists and parts into fully routed circuit boards? In a perfect world, I'd love to just define a bunch of parameters and DRC specifications then press a button for the process to begin. But, I know it's never that easy :)
So, what do you folks think about Orcad Allegro/SPECCTRA? Also, if not Orcad, what's your favourite PCB design studio?
Thanks,
deef





RE: PCB Auto-routing software: Cadence Allegro / SPECCTRA
We use Altium and you need to set up lots of design rules for the autorouter if you want it to auto-route reasonably.
HOWEVER there is a lot of work in placement and tidying up up the auto-routed board that some would perfer to just do it all by hand.
RE: PCB Auto-routing software: Cadence Allegro / SPECCTRA
This has been discussed a lot, recently enough, to still be completely valid responses.
thread240-185549: Schematic drawing programs
thread240-162059: PCB Layout Software
thread248-153459: PCB Software Suggestions
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: PCB Auto-routing software: Cadence Allegro / SPECCTRA
However, I worked at a company where they used an outside design house. One design was crammed with RF, Analog, multiple FPGAs, high-speed clocks, fine-pitch connectors. I designed using ORCAD schematic, wrote up a 10 page document describing signals and my thoughts, and accompanied by a AutoCad drawing/sketch of the board outline, mounting holes, possible connector locations for daughter boards, etc. The outside design house used full-blown Allegro with a high-end autorouter, and would turn the completed multilayer board layouts around in just a few days.
It is astonishing what can be done with the high-end routers in the hands of a PCB designer who specializes in the software package. The question is, will you be using the autorouter enough to become proficient at it?
RE: PCB Auto-routing software: Cadence Allegro / SPECCTRA
One method that I've found that works pretty well (using Cadence Spectra and/or Mentor Hyperlynxs) is to autoroute in stages, verify routing is acceptable, tweak by hand when neccessary, then lock the traces down to prevent rerouting. Sure this takes a bit longer, and isn't as exciting as pressing a button, crossing your fingers and hoping for the best, but it seems to work reasonably well for my level of complexity. (6 to 12 layers, with 1 to 4 layers of HDI on either side, 3 mil space / trace, etc.)
Hope this is helpful!
RE: PCB Auto-routing software: Cadence Allegro / SPECCTRA
An important question is "What size boards are you routing, and what is their density?"
If you're routing a 3" square dual-layer board with 50 components, an autorouter is probably going to be more of a hinderance due to the amount of time it will take to set up. If it's a 12" square 12-layer board with 2,000 components, an autorouter will only help you if you spend the time setting it up correctly.
Me? I do all of mine by hand up to 4 signal layers, TSSOP/0403 packages packed fairly dense. Anything beyond that and the autorouter gets to take a shot.
Dan - Owner

http://www.Hi-TecDesigns.com
RE: PCB Auto-routing software: Cadence Allegro / SPECCTRA
About a year later we had a new designer lay out a similar design. He chose to do it by hand and got the same performance level on a 4-layer PCB. This design had more engineering time but a significant cost savings on the bill of material.
I haven't found an autorouter that I like yet (although I've never worked with a package that cost over $20K either).
RE: PCB Auto-routing software: Cadence Allegro / SPECCTRA
RE: PCB Auto-routing software: Cadence Allegro / SPECCTRA
I could always get 100% route on an 8-layer board 12"x12" with 10 components, but then that's not very challenging ;)
Dan - Owner

http://www.Hi-TecDesigns.com
RE: PCB Auto-routing software: Cadence Allegro / SPECCTRA
RE: PCB Auto-routing software: Cadence Allegro / SPECCTRA
RE: PCB Auto-routing software: Cadence Allegro / SPECCTRA
Dan - Owner

http://www.Hi-TecDesigns.com
RE: PCB Auto-routing software: Cadence Allegro / SPECCTRA