Getting bridges in stencil reflow--should I scale pads or what?

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vputz
 
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Joined: Mon May 03, 2010 5:43 am

Getting bridges in stencil reflow--should I scale pads or what?

Post by vputz »

I made a small batch of 5 boards today with not-outrageous parts (QFP48, Evil Evil micro-USB connector). I thought my stencil (0.1mm PET) looked good, and I thought the paste looked OK, but every single one had bridges on the QFP and that evil evil evil micro-USB connector (future revisions are going to use a part that has legs that fit into holes; I'm tired of trying to place these by hand without being able to see the contacts).

But I can't figure out what's going wrong! Sure, occasionally there'll be a smear, but that's obvious and fixable. Should I be scaling the pads down for paste application (ie making the "paste area" smaller than the pads)? I don't even know how to do that in kicad.

It's a mystery, but there's no way I can make batches of these at this rate.

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