Electronics Forum | Mon Jul 16 11:25:22 EDT 2007 | davef
For the problem part, describe the pads on the board and the aperatures on the stencil.
Electronics Forum | Mon Jul 16 16:42:40 EDT 2007 | pnguyvu
Hi Jacky, It seems you have solder bead problem, beading occurs when the solder paste brick splatter as a component is placed into it, after reflow, the splatter becomes a spherical solder ball. Hope this will help. Steve USA STENCILS
Electronics Forum | Fri Jul 20 16:39:18 EDT 2007 | john_smith
Jacky, we have had a similar problem. We needed to go to a smaller nozzle and also check your vacuume system and air kiss.Could be after placement when the machine blows air to insure the part is off the nozzle that it is effecting the solder brick.
Electronics Forum | Mon Jul 16 10:44:29 EDT 2007 | Jacky
Hi All, Recently, we encountered strange defect at our SMT line. We can see solder ball spatter around at one of the component pad. This lead to insufficient solder defect at 1 side of the component. The other side of the component look good(Meet
Electronics Forum | Thu May 29 17:19:51 EDT 2008 | dyoungquist
On 0402s we use 20x25 mil pads with a 15 mil gap between the pads on the pcb with ENIG finish, 5 mil stencil with a 1:1 aperture (20x25 mil) and SAC305 lead free solder paste. We very rarely see any tombstoning on 0402s using this setup.
Electronics Forum | Fri Apr 17 10:44:29 EDT 2009 | rmitchell
Hi, follow up, Thanks to everyone that responded. We finished the build, the sun burst thru the clouds and the birds sang. Well that was a slight exageration. Sorry for lack of detail on the original post, I was frazzled. Since the 0201's were p
Electronics Forum | Thu Apr 11 20:35:22 EDT 2002 | davef
Messy. Messy. Messy. Consider gluing these components, until you control your process. It is unclear to us that a single factor drives these defects, but multiple factors that need to be tuned to work well together. PAD DIMENSIONS * Some SM-782 pa
Electronics Forum | Fri Apr 17 10:21:20 EDT 2009 | padawanlinuxero
have you try to change the stencil apertures to another figure like the one that look like a baseball home? I was having that problem and some solder beads and with that I was able to decrease the tombstones
Electronics Forum | Sat Apr 18 17:42:07 EDT 2009 | billwestiet
I like this suggestion the best as a "band aid", check out some of the low tombstoning solder pastes. I've seen these work.
Electronics Forum | Wed Apr 15 17:16:00 EDT 2009 | rmitchell
Hi, I am trying to reduce some 0402 cap tombstones. The main cause is the pad spacing is a little too far apart and the parts are as tall as they are wide .5mm I am stuck with the pad spacing for a while. All other parts are soldering well, even 0
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