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Re: [RFC]: New non copper pad paste and mask clearances behavior (was: What are the smallest values for pad paste and mask clearances)

 

The patch seems to work as intented.

But I thought Wayne said this won't be done because it would alter
interpretation of old existing board and footprints files. On the other
hand it's hard to imagine someone having designed footprints and boards
using and taking into consideration the global values, without noticing and
using this trick of using a very small value instead.

If this kind of change is made I think a more radical change would be more
logical. Why use these clearances for non-copper pads at all? I just can't
see why I or anyone would design a pad with certain dimensions and then
alter those dimensions on purpose with those clearance values. For example
I want a paste pad of 1.5x1.5mm. Why would I make it 2.0x2.0 and then
calculate values for paste clearance and % to make it smaller? Being able
to define the mask clearance for a paste-only pad makes even less sense.
Therefore they could be ignored completely and the corresponding GUI items
could be disabled or hidden. Instead of one explanation text which would
cover all cases with all pads it could be conditional: in the copper pads
it would read as it is, in the non-copper pads it would be "Clearance
values are not used for non-copper pads" or something as simple.

Eeli Kaikkonen

2018-05-02 15:58 GMT+03:00 jp charras <jp.charras@xxxxxxxxxx>:

> Hi All,
>
> Dick Hollenbeck ( who wrote a lot of code for Kicad) proposed to use
> global mask margin values only
> for pad at least on a copper layer.
>
> (I am thinking this is also what was expected by some of guys)
>

Attached, a patch to use global mask settings only for pads on copper
> layers to build the mask shape
> (solder or paste layer) of the pad.
>
> Therefore pads *only* on a solder or paste layer are no longer affected by
> global settings.
> (The drawback is a change in the behavior of previous Pcbnew versions, but
> it should not impact a
> lot of old boards or old footprints)
>
> The change in code is very small.
>
> I added a info message in dialogs, in the pad clearance setup sub-window
> to explain the purpose of
> this setting.
> This is perhaps the main problem, because a message in a dialog must be
> short, and yet understandable...
> The info messages are not perfect.
>
> Please, test it.
>
> --
> Jean-Pierre CHARRAS
>

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