Hello, I am a newbie with regards to making multilayers, and could use some
help with copper pour.
Copper pour worked fine for me with the 2-layer boards I made up to now.
However, I just finished my first 4-layer board with a (12+1516) layer
setup.
My expectation of this was, to get all simple through vias, connecting
whatever traces on each layer they meet.
So far so good.
As a last step, I drew polygons for the earth planes and did a copper pour
using Ratsnest.
This presented a problem: most of the vias were cleared by the copper plane,
as set by the isolation distances in the Design Rules.
But some vias now got connected to the ground plane.
If you have, f.i., a through via connecting layers 2 and 15, it seems as if
the program isn't aware of it being also present in the remaining outer
layers.
It just treats the via as a hole there, and sees no reason to maintain an
isolation distance between the via and the copper pour.
If I manually route an additional, very short (in fact, just a dot) piece of
trace from such a via onto the offending layers, then copper pour correctly
isolates these layers from the via. Because of time pressure, I scanned this
particular board visually several times and patched all vias so the
isolation was correct.
For a complicated board, this is quite a tedious task, and it's easy to
overlook a single via.
Is there something to be done, so the through vias will be recognised over
their full insertion length during copper pour, even if there is no trace
connected to them on that layer?
Any help is much appreciated.
Best regards,
Mike
