kicad-developers team mailing list archive

[Andy Peters <devel@xxxxxxxxx>]

> On Jul 9, 2018, at 10:24 AM, Seth Hillbrand <seth@xxxxxxxxxxxxx> wrote:
> 
> Hi Andy-
> 
> In the footprint you mention, note that there are many paste-only pads (see attached image).  To follow Silicon Labs' recommendation, simply create your exposed pad with no paste layer and add multiple paste-only pads in the geometry you desire.

I must have pulled an older version of that footprint, as that one has the paste-mask cut-outs and the one I used didn't. I see how that works. No need for a pad number, just create a pad with no copper layer and only the paste-mask layer and place as many as needed. Perfect.


> Note that there is a tutorial on the user forum (https://forum.kicad.info/t/tutorial-how-to-make-a-footprint-from-scratch/11092/1) that covers this.

Thanks for the link — I had not seen that.


> 
> -S
> 
> Am Mo., 9. Juli 2018 um 10:00 Uhr schrieb Andy Peters <devel@xxxxxxxxx>:
> I followed the discussion about “new non-copper pad paste and mask clearances,” hoping that it would suggest how to do something. Maybe I’m missing it.
> 
> I’m using a part in a QFN-44 package with the exposed pad. The library guys have created this footprint in https://kicad.github.io/footprints/Package_DFN_QFN and it’s the QFN-44-1EP_7x7mm_P0.5mm_EP5.2x5.2mm guy.
> 
> The recommendation from the chip vendor (Silicon Labs, but I’m sure it’s a standard recommendation) is for solder paste stencil to have a “3x3 array of 1.25 mm square openings on 1.80 mm pitch for the center ground pad.” The library footprint doesn’t have this stencil stuff, it’s just one big open area for solder paste. And I built a board with this footprint and now know why the recommendation is for the smaller openings in the stencil.
> 
> I figured this would be a good use of the “Custom Shape Primitives” feature in the footprint editor. But I can’t figure out how I’m supposed to enter anything into this dialog. The buttons are all grayed out. See:
> 
> 
> 
> 
> This is with yesterday’s “testing” build.
> 
> Am I missing something? Is this feature not yet implemented?
> 
> Application: kicad
> Version: (5.0.0-rc3-dev-5-gfd7f3b8), release build
> Libraries:
>     wxWidgets 3.0.4
>     libcurl/7.54.0 LibreSSL/2.0.20 zlib/1.2.11 nghttp2/1.24.0
> Platform: Mac OS X (Darwin 17.6.0 x86_64), 64 bit, Little endian, wxMac
> Build Info:
>     wxWidgets: 3.0.4 (UTF-8,STL containers,compatible with 2.8)
>     Boost: 1.61.0
>     OpenCASCADE Community Edition: 6.8.0
>     Curl: 7.43.0
>     Compiler: Clang 7.3.0 with C++ ABI 1002
> 
> Build settings:
>     USE_WX_GRAPHICS_CONTEXT=ON
>     USE_WX_OVERLAY=ON
>     KICAD_SCRIPTING=ON
>     KICAD_SCRIPTING_MODULES=ON
>     KICAD_SCRIPTING_WXPYTHON=ON
>     KICAD_SCRIPTING_ACTION_MENU=OFF
>     BUILD_GITHUB_PLUGIN=ON
>     KICAD_USE_OCE=ON
>     KICAD_USE_OCC=OFF
>     KICAD_SPICE=ON
>