Replies

• 

  Posted by NitWit at Fri Mar 18, 2011 5:09 pm

  Using the autorouter do not give you a warrenty, that all lines can be routed :-)

  My recommendations:

  Spend some more time in your schematics for optimization. Make it as easy as possible for the autorouter. F.e. if you are allowed, change pining of the connectors to avoid crossing of wires (in layout, not the schematics).

  Spend some more time in the parts placement. Reviewing airlines can give you a good impression about the work (and success rate) of the autorouter before you start routing. This is of course an issue of personal experience.

  My personal rule is to route power supplies like DC/DC converters always by hand, following the layout recommendations from the controller manufacturer. Well, my typical designs are complete done by hand, I use the autorouter only for checking, if the autorouter may reach 90%. In that case, I know, that the design can be finished.

  Think about 2 additional layers for power and GND. Regarding your design, you have parts on the same power level all over the board. Having an extra power plane for Vcc and GND would make live much easier.

   

• 

  Posted by qczek at Fri Mar 18, 2011 8:11 pm

  Hello,

  Thank you for your replay. I use a lot of TO/FROM symbols on my schematic, so a lot of connection seems to be not made, but when I use highlight net function, everything is ok. The location of components, and pcb size is determined by stm32 kit which will be used together as quadrocopter controller, so I can’t move any connector on this pcb.

  I just tried to auto route only one net 0V, without success, and I found out the problem is cause by elements located to close to pcb edge (it will be nice to get some detailed log, to found something about reasons of fail). I made the changes and now it works. I will try to rout all net again to see the result.

  Thanks

  Krzysiek

• 

  Posted by qczek at Sun Mar 20, 2011 4:05 pm

  Hi,

  After hours of partialy manual tracing, i got success, but i have a lot of T-D errors (Track to Drill Hole error (T-D) at (15449 18245) on layer "Bottom Copper".
      Track too wide to backoff from drill.)

  What does it mean, and how to fix the errors (99% of errors is connected to autorouted tracks).

  Thank you in advance

  krzysiek

• 

  Posted by qczek at Wed Jul 20, 2011 2:52 pm

  Hello,

  I'm trying to auto route quite simple 2 layered pcb, but unfortunate, even after 60 passes router can’t complete all tracks...

  I have tried to limit tracks to 8mils, but without results L

   

  Connections

  Attempted 197

  Completed 102 (51%)

  Failed 95

  Total vias 124

   

  It’s my first computer designed pcb, so maybe I do something wrong…

  Attachment contains the schematic view, and partially routed pcb.

  How can I achieve better results?

  Thank you in advance

  Krzysiek

• 

  Posted by KennyMillar at Wed Jul 20, 2011 3:14 pm

  I would start by looking at the design rules.

  These are the rules the autorouter will try to adhere to, and the rules the design rules check will verify.

  They are very conservative by default, and most board houses can manufacture to much closer tolerances. Get the data from your board house (ask for their 'specification' or DRC data) then update your spacings and clearances to match.

  To do this you open your pcb file and go to Settings / Design technology and select the Spacings and Rules tabs and enter the data from your board house.

  Also, I usually find that I get much better results by doing a full manual routing - the routing controls in DS are very powerful once you get used to them.