Electronics Forum | Tue Feb 04 22:28:16 EST 2003 | davef
You could reduce the paste by about 70%. Solder balling and tombstoning will be the issues to fight. The drivers to these don't change with the component size. Use the fine SMTnet Archives for background. Aperture Size and Thickness of Solder Pas
Electronics Forum | Thu Feb 24 11:02:29 EST 2000 | mark scheunemann
I am looking to discuss 0402 issues, specifically tombstoning/unsoldered. Any recommendations on pad size/spacing, stencil design etc would be helpful. Placement and reflow profile look good.
Electronics Forum | Thu Feb 24 11:02:29 EST 2000 | mark scheunemann
I am looking to discuss 0402 issues, specifically tombstoning/unsoldered. Any recommendations on pad size/spacing, stencil design etc would be helpful. Placement and reflow profile look good.
Electronics Forum | Thu Oct 30 22:29:58 EDT 2008 | davef
For most applications, a nice square [or rectangle] pad works just fine. Assemblers ship boat loads of boards with these every day. It's reasonable for tight decoupling capacitor requirement applications to use round or radiused pads for components
Electronics Forum | Tue Feb 04 17:24:07 EST 2003 | jonfox
we have some pretty tight 0402 placements and our best fix was to reduce the pad (vertically speaking) from .030x.022 to .020x.022. Fewer tombstones and the paste flows out to the edge of the pads nicely. Only difference is that we have a 6mil sten
Electronics Forum | Wed Feb 05 14:20:45 EST 2003 | Stephen
One thing that worked for me was simply rounding off the pads, making square pads into circlesfor the stencil. It worked but did seem a little strange turning squares into circles for 0603's and 0402's and turning cirlces for BGA's into squares, (bu
Electronics Forum | Tue Feb 04 09:03:45 EST 2003 | Russ Roberts
Greetings, I am pretty new to SMT production, and have learned much from this forum. I am getting ready to build a CCA with many 0402 parts that are really close together. I consider these fine pitch. The board also has two QFPS, so my stencil design
Electronics Forum | Wed Feb 05 21:24:35 EST 2003 | davef
Stephen's correct. Radiased outer corners on 0402 pads really do seem to improve things. We aim to try "squared-up semicircles".
Electronics Forum | Wed Feb 05 10:23:26 EST 2003 | russ
Are these the only packages that you could come up with Dave? What about all the rest? You're something else. Thanks for doing my work for me! Russ
Electronics Forum | Wed Feb 05 13:56:40 EST 2003 | davef
I figure if you need the rest, you don't need these. These strips are from some laser cutting tool fabricator. They give them to their customers [laser cut stencil fabricators] so the customer can do a good job. Yall have a nice day now, y'hear?
