Electronics Forum | Mon Mar 11 06:49:42 EDT 2019 | SMTA-Bob
You problem will be related to the part type or the design. Standard 40 or 100 pin QFN or LGA parts are not going to drop due to weight as they are just a few grams. If you send a photo of the PCB pad footprint and the component separately I may be a
Electronics Forum | Thu Aug 24 15:37:50 EDT 2006 | Chunks
Hi Any, This is from an earlies thread "Solder Ball After Reflow Process". Date: August 16, 2006 01:52 PM Author: Russ Subject: Solder Ball After Reflow Process Oven settings are meaningless here. What does the board see? It is the paste we a
Electronics Forum | Wed Feb 04 08:00:30 EST 2009 | milroy
Hi, It depends on the stencil thickness, aperture size and the component footprint. For exampl if you have a PCB with QFP,CSP,QFN & BGA parts then this underwiper is not useable because you will still find solder cream deposits in the apertures aft
Electronics Forum | Wed Jul 06 06:17:11 EDT 2016 | pavel_murtishev
Dear members, Recently we have found that solder mask thickness variation could lead to solder balling under QFN packages for a high reliability device. Is there any industry proven method for solder mask thickness checking? Any equipment or any me
Electronics Forum | Thu Aug 19 18:29:58 EDT 2021 | tey422
It's more about how difficult to handload the those extra parts at the end of kit. i.e. big size connector, doesn't require extra. Micro parts like QFN, QFP would be depend on the kit size; under qty of 50, 1 or 2 extra would be good. If qty over 1
Electronics Forum | Tue Apr 25 07:44:39 EDT 2006 | Holly
MikeL, I came across your post. We are also a small company looking at rework systems for BGA/QFN/CSP. .5mm worse case pitch. We had a PACE 1700 on trial and we found it clunky and unreliable. We also evaluated a PDR 410 system and found it better
Electronics Forum | Mon Feb 05 20:43:27 EST 2001 | davef
1 Solder on gold fingers comes from: 1a About 70 % of the time it's caused by poor cleaning of screen printer, staging area (table), conveyor, reflow oven chain or belt, and keeping boards separate from cleaning process 1b After loading paste onto
Electronics Forum | Sat Mar 14 09:12:59 EDT 2009 | davef
First, there is no good justification for getting solder on gold fingers. Second, it is well known that solder on gold fingers is unacceptable. So, shipping boards with that condition indicates sloppy quality practices at your CM. Third, that being
Electronics Forum | Tue Apr 19 16:20:05 EDT 2016 | davef
Don't blame it on the poor paste thickness requirement [although I might go on to argue that it's could be a contributor to the issue]. Most likely you're the problem. About 70% of the time solder on gold fingers is caused by poor cleaning of screen
Electronics Forum | Fri Dec 01 15:06:54 EST 2017 | emeto
I am not sure that is doable. Ground Aperture is very small(for the stencil blade to get in there) and very close to the other apertures. I want to say the minimum requirement for step is 6mm clearance from other apertures for the stencil houses that
