5 ms·

Perhaps you didn't read the article. Author's example circuit is fairly simple with handful of components. He estimates it would take him 10 hours to do manual

Perhaps you didn't read the article. Author's example circuit is fairly simple with handful of components. He estimates it would take him 10 hours to do manual routing to satisfy all the constraints. If things were more complex, I can easily see multiple days worth of effort. So, no, problem is not trivial and would save far more time than just 15-minutes. Double sided PCBs costs almost same as single sided however going from 2 layer to 4 layer literally doubles the cost. Going from 4 layers to 6 layers increases cost by 50%. For boards like Raspberry Pi or Arduino, this could make massive difference if you doing production at scale. So the problem is very real.

stephen_g 9y ago
I'm not sure if the author is the best reference though - a professional designer with good tooling wouldn't take anywhere near that long. Professional tools like Altium, Allegro, etc. have really good interactive routing tools, and some pretty cool semi-automatic routing tools where you select groups of nets, plot an approximate routes, and it works out the finer details. This can make routing busses and stuff almost as fast as routing single tracks. Secondly, sometimes dropping layers isn't an option - given EMI/EMC requirements you're going to need a ground plane in almost all high speed designs (anything over a couple of hundred hundred MHz). So for a lot of designs, four layers is the minimum. Add in impedance control, or RF, and you might need to go to eight (RF microstrip always needs to be next to a ground plane, or stripline needs one above and one below. So you can end up needing a lot of layers especially once you add in power planes). At the end of the day, it's a trade-off between lots of different factors, and I don't think (for any skilled professional) that the quality of the route would really come into it much...
- madengr 9y ago
  Took about 1 second to realize there were no bypass caps on the board. I stopped reading with any depth at that point. Autorouters meet all physical rules, while violating all electrical rules. Manual routing with the application of push and hug (semi-auto) routing is the way to go. No one just pushes an autoroute button.
- cottonseed 9y ago
  Or sketch routing: https://www.youtube.com/watch?v=fIi13gI9xEA https://www.youtube.com/watch?v=fIi13gI9xEA

stephen_g 9y ago

I'm not sure if the author is the best reference though - a professional designer with good tooling wouldn't take anywhere near that long. Professional tools like Altium, Allegro, etc. have really good interactive routing tools, and some pretty cool semi-automatic routing tools where you select groups of nets, plot an approximate routes, and it works out the finer details. This can make routing busses and stuff almost as fast as routing single tracks. Secondly, sometimes dropping layers isn't an option - given EMI/EMC requirements you're going to need a ground plane in almost all high speed designs (anything over a couple of hundred hundred MHz). So for a lot of designs, four layers is the minimum. Add in impedance control, or RF, and you might need to go to eight (RF microstrip always needs to be next to a ground plane, or stripline needs one above and one below. So you can end up needing a lot of layers especially once you add in power planes). At the end of the day, it's a trade-off between lots of different factors, and I don't think (for any skilled professional) that the quality of the route would really come into it much...

madengr 9y ago
Took about 1 second to realize there were no bypass caps on the board. I stopped reading with any depth at that point. Autorouters meet all physical rules, while violating all electrical rules. Manual routing with the application of push and hug (semi-auto) routing is the way to go. No one just pushes an autoroute button.
cottonseed 9y ago
Or sketch routing: https://www.youtube.com/watch?v=fIi13gI9xEA https://www.youtube.com/watch?v=fIi13gI9xEA