Arduino Forum

Development => Other Hardware Development => Topic started by: liuzengqiang on Jul 06, 2018, 07:14 pm

Title: EAGLE net class question
Post by: liuzengqiang on Jul 06, 2018, 07:14 pm
I've had this question for a while. It has become more of an issue the bigger board I'm designing. Here it is:
First of all, I am using EAGLE 6.6.

I use two net classes to distinguish power connections from signal connections, with different trace thicknesses. This works well on smaller boards. There is plenty of space to run thicker traces.

But when I design bigger boards, some traces that connect say pullup resistors to 5V are also made thick by the auto router but really don't have to be thick. Making them thin saves space for more traces.

But if I go manual and thin out the traces, I fear that EAGLE doesn't understand what I did and will rely on this thin trace to daisy chain to thick power traces to power other parts of the board.

So are there any methods to tell EAGLE not to daisy chain certain connections such as when thinner traces are used instead of net-class defined thickness or am I worrying about things that will never happen? Thanks.
Title: Re: EAGLE net class question
Post by: westfw on Jul 07, 2018, 11:48 am
Not that I know of.  I usually manually route power traces (or re-route) to make sure all the actual power connections are thick enough.  I MIGHT let the autorouter deal with the pullups/etc.  (that usually means the power "class" is set thicker than the "default", but not as thick as I want the actual power connections to be.)
Title: Re: EAGLE net class question
Post by: CrossRoads on Jul 07, 2018, 01:53 pm
You can route the wider traces for power manually, then set the power class to thinner and let it autoroute the pullups and connections to ICs, especially SMD, thinner.