Rules are driving me nuts... Some help would be appreciated

[Ice-Tea]

This is driving me bonkers. I have a PCB with some stringent isolation requirements. So, obviously, I need some rules. They seem to work, kinda, but also not. For simplicity, I disabled most rules except for these:


Basically, "regular" 0.2mm clearance, 6.1mm clearance on outer layers and 2.5mm on inner layers. So far so good. Now look at the picture. I took a trace from "IO3" and routed it towards "IO2". Obviously, the rules made me "hit the wall". You can see a 6.1mm clearance to a pad (SOIC IC) with "ISO2", which is correct. It also shows the clearance to a much closer pad, basically the TH pad of a Y2 cap. Clearance there is much less, less than 2.5mm even.


So... What the heck is going on?? From what I can tell, all TH constructs (including vias I think) are not taken into account for the clearance... So, why? And how can I fix it?

[AlfBaz]

So... What the heck is going on?? From what I can tell, all TH constructs (including vias I think) are not taken into account for the clearance... So, why? And how can I fix it?

Bit of a gotcha I guess. Whilst through hole pads and vias have parts of them ton the top layer they are actually classed as being on the "Multilayer"

[Ice-Tea]

So, as far as rules go they do not exist on top and bottom per example? 

Kill me now... 

[Ice-Tea]

OK... follow up question.I can see how I could cook up a rule against "Multilayer". But how then would I make a rule that would have a different clearance for multilayer parts on outer and inner layers?? 

[T3sl4co1l]

Try (OnOutside OR OnMultiLayer) instead of named layers.

Tim

[Ice-Tea]

Yep, that's better. Now for the following part: a mechanical, non-plated hole is also a multilayer part. So that also generates errors where it should not. Can obviously exclude "No Net" parts but my clearance rules are starting to read like an encyclopedia.

[T3sl4co1l]

They don't have to be pretty, they just have to work...

And hey, it's not like it's the tax code (which doesn't even have to work!)...

Tim

[Ice-Tea]

They don't have to be pretty, they just have to work..

Ah, well, this is where the customer disagrees. He likes things pretty.

[free_electron]

ONOUTSIDE OR ISVIA OR ISPAD