Electronics Forum | Mon Nov 01 10:29:13 EDT 2010 | scottp
I've searched the archives and maybe my search skills aren't up to snuff but I couldn't find much. I'm curious what people are doing for 0.4 mm pitch BGAs, assuming a type 4 paste. Pad diameter? SMD or NSMD? Stencil thickness? Aperture diameter? Us
Electronics Forum | Thu Nov 15 08:25:08 EST 2007 | rgduval
I do think that the designer goofed, and used too large vias. I believe he only used on size via on the entire board, regardless of whether it was in a pad, or out on the board. I have seen vias in pad work, though. From a manufacturing standpoint
Electronics Forum | Mon Nov 30 08:39:05 EST 2015 | spoiltforchoice
http://blog.screamingcircuits.com/2010/09/smd-vs-nsmd.html such as this? Which handily also tells you what you might want to google.
Electronics Forum | Tue Sep 20 23:12:38 EDT 2005 | darby
Several suggestions. Your hands may be tied but here goes. 1. Doctor your stencil so that pads are not shared etc and reduce the apertures more that what you would normally. This may stop one pad wetting into another etc. 2. The use of a Pb-free sol
Electronics Forum | Tue Jun 02 21:27:22 EDT 2009 | davef
We've never heard of a situtation where oversized pads caused voiding. Your supplier is correct that the pads on the board should be the same size as the pads on the interposer, but this is to improve reliability issues. Search the fine SMTnet Archi
Electronics Forum | Thu Jun 04 20:06:30 EDT 2009 | davef
Since posting the above comment extolling the virtues of NSMD pads and disparaging SMD pads, we've learned that the points apply to all array devices, but in spite of that some designers of fine pitch [eg, 0.4, 0.5mm pitch] array devices choose SMD w
Electronics Forum | Thu Sep 06 05:25:38 EDT 2018 | spoiltforchoice
I'm no expert but I think you will find the majority of discussions around BGA & good printing results focus on the PCB design and things like tented vias and pad definition. e.g https://macrofab.com/blog/bga-pad-creation-smd-nsmd/ After that, work
Electronics Forum | Thu Jul 16 12:50:36 EDT 1998 | smd
200 boards an hour and probably does. Our slow P&P machine keeps us from getting that benefit. But we get to have all the headaches. I think the printer runs on a 286! That's pretty sorry for such an expensive piece of equipment. The stencil frame is
Electronics Forum | Mon Mar 23 16:38:09 EDT 2020 | emeto
Steve, On 16mil pitch I would try 12mil diameter on 5mil stencil, unless the BGA ball size is something unexpectedly huge.
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.
