> This is because the track end is rounded (diameter=3Dtrack width) and it =
is backed off
> so the rounded end just touches the hole during the plotting output stage=
.. If the
> track is too wide or the pad diameter is too small, the track has to be b=
acked of so
> far that there are two small cuts between the track and the pad. This can=
 cause
> over-etching during manufacture.
>=20
> If this would happen, designspark does not backoff the track so the track=
 coveres
> the drill hole.
>=20
> I don't know if this really is a problem or even if the board manufacture=
rs does
> plot the layout with holes in the pad.

What a weird way of doing it. My understanding is that Orcad ends the track=
 on the hole centre. I regularly put small hole/pad vias in wide tracks (i.=
e. the pad used is smaller than the track width), that would create a probl=
em if back-off was used.

I can't see a reason for doing the back-off. The situation you describe abo=
ve will create chemical traps for the etchant, which are a definite no-no, =
as that will likely create problems with corrosion further down the line, a=
s well as any over-etch problems that may exist.
--=20
Scanned by iCritical.

--=20
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