kicad-developers team mailing list archive

[Lorenzo Marcantonio <l.marcantonio@xxxxxxxxxxxx>]

On Wed, Mar 27, 2013 at 04:38:44PM -0500, Karl Schmidt wrote:
> It could take two layers to do this - One layer to mask-out the
> default paste and a second layer to put in what you want. But I
> don't think many are using it at all so just reversing the function
> might be a simple useful fix.

You're talking about solder paste removal... having mounted some
D3PAK components I tell you how I handle it (also useful for IC with big
thermal pads).

1) Don't set the paste layer in the main pad properties
2) Add individual pads *only* in the paste layer for each blob of paste
   you actually want

Even with huge components you usually don't need more than 9 blobs, it's
actually quite fast to do. You could even script it...

Anyway this is an extremely process dependant operation (IIRC average
reduction is from 40% to 60%) since varies with stencil thickness,
stencil cut method, paste grade and even reflow curve... in practice our
fabricator usually says: 'put a single big pad and we adjust the
stencil'. Even when the stencil layout is in the component datasheet!

-- 
Lorenzo Marcantonio
Logos Srl

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