Electronics Forum | Mon Aug 23 03:12:57 EDT 2010 | grahamcooper22
Possible route causes of bridging on fine pitch ICs are; too much paste (stencil aperture wrong), poor print quality (paste smudges during printing), pcb pads not flat depending on the solderable coating, paste has poor cold slump properties, too muc
Electronics Forum | Wed Jun 14 09:34:25 EDT 2017 | cyber_wolf
In my experience there is no need for wet wiping stencils. We run 0201'and micro BGA's daily with no issues. If you are having paste release issues, I would be looking at other things. Aperture area aspect ratio, aperture design, land design, sold
Electronics Forum | Thu Sep 07 08:45:02 EDT 2017 | dleeper
In my experience with similar sized parts, the nano coatings (or what ever your supplier might call them) do help with repeatable paste release. How are you cleaning your stencils? A big red flag to me is that your stencil worked fine for the first
Electronics Forum | Wed Aug 29 03:16:20 EDT 2018 | cannizzaro
It is recommended that the thickness of the stencil of 0.1mm, the steel mesh should be partially nano-coated. It is best not to dry easily, and the particles are not easy to be too large. I have tried ALLPCB for this kind of BGA in the past and they
Electronics Forum | Mon Jun 28 08:25:54 EDT 2004 | Scott Dodge
What is the difference between a smooth finish organic coated bare copper board for fine-pitch components and HASL finish?
Electronics Forum | Tue Sep 14 09:35:47 EDT 2004 | JB
We have been using SANFORD Gold Coat and are pleased with it so far. It's a meallic marker. Hope it helps.
Electronics Forum | Thu Jul 21 07:15:27 EDT 2011 | ccouture
I cleaned the stencil with IPA 99% before applying the Rain-X. Apply Rain-X as per instruction.
Electronics Forum | Thu Jul 21 07:21:47 EDT 2011 | ccouture
So far after ~1500 units printed with the stencil treated once with Rain-X, no issues were detected with solder joints. The only difference is no more solder bridges on fine pitch with .010" openings. The print is picture perfect on all pads, nice an
Electronics Forum | Thu Sep 07 10:18:24 EDT 2017 | capse
Chrys Shea has published extensively on stencil materials, coatings and paste release mechanisms. Many of the papers are available to download on her website. Just search for Shea Engineering Services. I've worked with Chrys in the past, she is defin
Electronics Forum | Fri Mar 27 03:42:17 EDT 2020 | sssamw
Did you try 0.12 or 0.1mm nano coated stencil @ 10 mil aperture? A soak time type profile with long reflow time could help.
