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Electronics => PCB/EDA/CAD => KiCad => Topic started by: metRo_ on October 06, 2013, 02:46:25 pm

Title: Design component footprint with kicad
Post by: metRo_ on October 06, 2013, 02:46:25 pm
Hi,
I'm designing the following component on kicad http://cds.linear.com/docs/en/datasheet/3469f.pdf (http://cds.linear.com/docs/en/datasheet/3469f.pdf)

(http://i.imgur.com/Jm7sMEl.png)

I want to set a pad clearance of 0.2mm but the only way I found to do it was to add a clearance of 0.1mm to each pad but that makes the most left and right pads to has only 0.1mm of pad clearance like the top clearance.

How would you do that?

thanks :)
Title: Re: Design component footprint with kicad
Post by: Thor-Arne on October 06, 2013, 04:01:14 pm
Many of the footprints I've seen have overlapping pad clearance, just set it to 0,2mm ?
Title: Re: Design component footprint with kicad
Post by: metRo_ on October 06, 2013, 04:45:51 pm
That way you have DRC errors :s
Title: Re: Design component footprint with kicad
Post by: Thor-Arne on October 06, 2013, 06:16:46 pm
Doh, didn't think of that at the time i replied.  :P
Guess that's another issue with the standard kicad libs.

I can't see any options for offsetting the pad clearance, perhaps hacking the .mod file directly....  :-//
Title: Re: Design component footprint with kicad
Post by: elgonzo on October 12, 2013, 10:24:41 am
Quote from: metRo_ on October 06, 2013, 04:45:51 pm
That way you have DRC errors :s

Nope, overlapping pad clearances don't cause DRC errors in KiCAD (wouldn't makes sense, anyway).
Perhaps ancient KiCAD versions had this issue, i don't know.

However, if your reply was to Arne's second picture, it indeed looks like adjacent pads poke into the clearance area of each other. Which would cause DRCs of course...
Title: Re: Design component footprint with kicad
Post by: elgonzo on October 12, 2013, 10:25:27 am
Quote from: Thor-Arne on October 06, 2013, 06:16:46 pm
Doh, didn't think of that at the time i replied.  :P
Guess that's another issue with the standard kicad libs.

I can't see any options for offsetting the pad clearance, perhaps hacking the .mod file directly....  :-//

The Pad properties dialog has two tabs. The second tab contains what you are looking for :)
Title: Re: Design component footprint with kicad
Post by: Thor-Arne on October 13, 2013, 08:58:14 am
Quote from: elgonzo on October 12, 2013, 10:25:27 am
Quote from: Thor-Arne on October 06, 2013, 06:16:46 pm
I can't see any options for offsetting the pad clearance, perhaps hacking the .mod file directly....  :-//

The Pad properties dialog has two tabs. The second tab contains what you are looking for :)
Where? I cant see any offset for the pad clearance in  that tab.
You can easily offset the pad, but not the clearance.

The problem is solved by using 0,2mm clearance and have the clearance overlap without overlaping the pads themselves.

I don't use smd much so I haven't noticed this problems in the libraries.
It seems that the issue lies with the values set to 0 (zero) so that they use the global defaults, which perhaps have changed from release to release.