On my current design, I want to set a width rule for some nets which provide power in order to get them fatter. I set a net class on the net,set a rule and it works pretty well.

Now, this net is also used as an input on a ADC pin of a microcontroler. The first thing is that I don't need a fat connenter image description hereection for this purpose, the second is that there's no way to connect a fat line to only one pin on the microcontroler.

Is there a way to exclude a part of the net class from the rule ? Or a specific rule but based on which information ?

Here are two screenshots for illustration purpose.

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Three approaches:

  • Use a net-tie: A net tie will create two distinct nets (each has its own name) but they are actually joined. Information on how to create & use a net tie can be found here.
  • Use a 0R resistor. Again, this will create an additional net.
  • Scope your rules so that they target only specific areas. You can either target your rule to only apply within a specific room or within specific coordinates on your board.
  • \$\begingroup\$ Would a Neck-Down rule be of any help here? techdocs.altium.com/display/ADRR/… \$\endgroup\$ – Armandas Jan 3 '16 at 13:31
  • \$\begingroup\$ No, the Neck-Down rule only applies to pad entries, not to tracks themselves. You will need to scope the Routing -> Width rule to your desired values. Even if you set up a Neck-Down rule you would still get the width rule violations. \$\endgroup\$ – Tom L. Jan 3 '16 at 13:48
  • \$\begingroup\$ Net ties, really interesting. Would be cool to be able to resize each of them directly on the PCB... \$\endgroup\$ – Julien Jan 3 '16 at 17:51
  • \$\begingroup\$ That would be too easy ;-). Yet, experience has shown that for 90% of the cases where you need them, basically 3 or 4 different sizes are enough. \$\endgroup\$ – Tom L. Jan 3 '16 at 18:25

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