Electronics Forum | Tue Jan 13 22:43:11 EST 2004 | davef
We have seen this in reflowed parts, where there is flux res collected in the dimple in the solder, where the lead 'presses' in the solder. Generally, we attack this as a thermal issue: * Thermal pads sucking the heat away from the leads. * Leads no
Electronics Forum | Thu Jan 15 15:08:43 EST 2004 | mrmaint
Are your qfp's being stored properly. I have seen this in the past and it turned out to be a moisture issue. We saw most of the problems on the corners. The component would swell during the reflow process thus lifting the corners. After baking the re
Electronics Forum | Mon Jan 12 08:59:57 EST 2004 | Paul F
I may have a similar problem at the moment with a QFP-68. Do the unsoldered leads leave a perfectly formed footprint in the reflowed solder? Do you usually find this issue occurring towards the corners of the QFP rather than in the middle of a row?
Electronics Forum | Thu Jan 08 15:03:40 EST 2004 | dwzeek
We have an ongoing problem with our QFP144 packages soldering. It has not received much attention until late due to some customer failures. Most of the failures would show up in ESS testing and be repaired. The failure rate is about 2 in 1000 parts f
Electronics Forum | Thu Aug 30 12:31:26 EDT 2018 | emeto
We all agree that you have a PCB issue. It would be for the best if you use a lab to investigate a few of these PCBs. It would be interesting to investigate the plating specs and contamination levels. For a start you should insist on proper packaging
Electronics Forum | Fri Aug 24 12:24:35 EDT 2018 | davef
Could be ... Consider this: The LED and the BIG pad reflowed before the small pad. The superior force of the solder on the BIG pad pulled the LED over and the LED took the solder on the little pad along with it. Try this: Print paste on a board. No
Electronics Forum | Thu Aug 30 14:49:54 EDT 2018 | benreben
Don't search in your profile or your process. The problem is the PCB!
Electronics Forum | Thu Aug 30 16:17:07 EDT 2018 | emeto
First suspect PCB contamination - clean the boards, bake/dry them, try again.
Electronics Forum | Thu Sep 20 07:28:19 EDT 2018 | proceng1
I agree, your PCB has contamination or something.
Electronics Forum | Thu Oct 25 14:36:42 EDT 2018 | etmpalletguy
Look at the Stencil man! Give me a call offline if want, I'm with Stentech, tooling & stencils...
