Electronics Forum | Fri Dec 03 13:08:40 EST 2004 | Dreamsniper
The voids are between the interface of the pad and the solder joint of component chips. I have a good thermal profile and this problem occured only on certain product so since we have some common components, component termination contamination is no
Electronics Forum | Fri Feb 01 19:07:57 EST 2013 | hegemon
We have had some success in void reduction with LGA by pre-tinning or "bumping" the devices before placement. The extra solder seems to allow a slightly higher standoff, and allows better outgassing, is my guess. A lot more labor , but the results
Electronics Forum | Thu Sep 26 14:45:36 EDT 2019 | dwl
Excellent X-ray picture, very helpful! It looks like you have a lot of voiding on the center thermal pad. My guess is that outgassing is pushing solder off the pad which is forming solder balls outside the body of the component package. The first
Electronics Forum | Fri Jun 25 13:35:13 EDT 2004 | tcp
We have beaten the reflow profile angle to death and haven't been able to duplicate the condition, so I don't think that is the problem. The voids were visible on the surface of the remaining solder. Where the lead tore out of the solder left indic
Electronics Forum | Fri Jul 20 08:16:48 EDT 2007 | hussman
Wow, I've never heard of this. If it voids during cure you either have a hot profile or bad adhesive. We use Loctite Chip Bonder. No problems.
Electronics Forum | Fri Jul 25 07:26:45 EDT 2008 | realchunks
From what I can understand, you say this only happens on one type of BGA (?). Try baking this BGA. You may have out gassing during rework. Do you use tacky flux during rework? If so, try a different flux. And last, check your rework profile.
Electronics Forum | Thu Sep 02 04:51:35 EDT 2010 | sachu_70
Seems interesting ... I am certain this could be resolved. But first one question: How did you monitor the reflow profile at this component? How and where was the thermocouple connected?
Electronics Forum | Thu Oct 25 13:39:29 EDT 2012 | cyber_wolf
Wait a minute...Your peak temps are PbFree like. Why is your profiler looking at time above 183 ? What is the time above 217 ? I thought we were looking at time above 217 not 183.
Electronics Forum | Mon May 27 04:36:08 EDT 2019 | SMTA-Rogers
Dear Sr.Tech, We tried to adjust the soak time and TAL time of reflow profile, but it doesn’t seem to help much.
Electronics Forum | Thu Jan 02 10:30:42 EST 2020 | emeto
thank you Steve, when you mention Stencil design, what do you refer to? How about the Reflow profile? Any specifics that I should look for. Everything is in my process window, but some detail towards this package might be very helpful.
