kicad-developers team mailing list archive

[Eeli Kaikkonen <eeli.kaikkonen@xxxxxxxxx>]

Are we talking about the same thing, and have I completely understood what
"net pad clearance" means? I don't quite get what you mean.

I'm talking about the pad-to-pad and pad-to-track clearances. Paste-only
and mask-only pads don't seem to have that at all in practice and it's not
applied to mask or paste layers even in pads which have copper layers.

For example I have experimental footprints with separate copper, paste and
mask pads in separate locations. When they are put into a board the mask or
paste pads of two different footprints can even overlap without DRC errors
while copper pads can't be too close to each other. If in the Display
Options I check Show pad clearance, the copper pads have clearance lines
around them but paste and mask pads don't. So I think that "Net pad
clearance" haven't had any effect for non-copper pads even before these
recent changes. There's no clearance value left in these four fields which
would be applied on non-copper pads (which Wayne called "aperture pads").

Based on that I think it would be correct to say "clearance values are used
only for pads on copper layers". Unless "pads on copper layers" is too
inaccurate. It looks like "pads which have at least one copper layer" would
be more accurate because that seems to make the difference whether
clearances are applied or not, and only the copper layers have "net pad
clearance". Anyways, the current text leads one to think that "net pad
clearance" would be used for non-copper pads.


Eeli Kaikkonen


2018-05-06 1:38 GMT+03:00 Jeff Young <jeff@xxxxxxxxx>:

> Hmmm… I actually changed that on purpose because I thought the other was
> misleading.
>
> We build the masks for the mask layers differently depending on whether or
> not the pads have *any* copper layers.
>
> We don’t treat the pad clearance differently based on that constraint.
>
> Now it’s true that we only check clearance between two items on the same
> copper layer, but that’s subtly different than “not on any copper layer”.
>
> Perhaps too subtle?
>
>
> On 5 May 2018, at 20:19, Eeli Kaikkonen <eeli.kaikkonen@xxxxxxxxx> wrote:
>
>
>
> 2018-05-03 23:39 GMT+03:00 Jeff Young <jeff@xxxxxxxxx>:
>
>> I’m happy to clean up the dialog if JP wants to check in what he has.
>> Just let me know….
>>
>
> It looks cleaner now, but I noticed that the information is a bit
> misleading. It says "solder mask and paste values are used only for pads on
> copper layers" while actually it seems to be true for all the clearance
> values, also the net pad clearance. That would make the text simpler and
> shorter: "clearance values are used..."
>
> I still don't know why the value fields should be editable for non-copper
> pads because they are not applied anyways. Well, this is nitpicking, so it
> can be ignored...
>
> Eeli Kaikkonen
>
>
>