Electronics Forum | Tue Jan 12 15:29:40 EST 2010 | davef
What is your concern regarding voiding in QFN solder connections?
Electronics Forum | Thu Sep 02 06:22:34 EDT 2010 | sachu_70
Good. This is the right way to profile. Let me ask you, have you anytime soldered QFN componets on your boards? The concept of LGA soldering is similar to that used for a QFN package. QFN soldering also exhibits void formations, and is an inherent pr
Electronics Forum | Fri Apr 06 11:10:43 EDT 2012 | cadco
We are a PCB design house/CM and we have found that if you elongate the QFN pads to the outside of the part by .025 to .030 you then have the opportunity of doing touch-up manually with a soldering iron should there be a voiding issue. This would hav
Electronics Forum | Fri Jul 19 13:02:01 EDT 2019 | davef
Double-check me on this, but I don't believe that A-610 [IPC-A-610] requires side fillets on QFN solder connections, because the sides of most terminations are not plated. Plating on the bottom of the termination is sufficient for a proper solder con
Electronics Forum | Thu Aug 10 11:24:18 EDT 2017 | dleeper
The exposed metallization on the sides of the QFN probably aren't tinned and therefore not expected to have solder wetted to them. If previous parts formed nice toe filets, it might just be that those parts were fresher and the exposed metal did not
Electronics Forum | Mon Nov 19 13:13:51 EST 2007 | hegemon
We have found differing results based on the pattern used when reducing to total % of solder paste on the center pad. We arrived at 68% coverage on the center pad, and 1:1 for the perimeter pads. To get the 68% coverage we used a number of differen
Electronics Forum | Thu Aug 10 10:52:11 EDT 2017 | ttheis
We are just using a stereo microscope at this time. When we first started out with these parts a year ago they filleted very well but with no apparent change they began having problems. While the boards do work, we are concerned about the long term r
Electronics Forum | Sat Dec 02 10:23:47 EST 2017 | tomh
Have you ever heard of "Solder Mask Defined Thermal Pads"? I wrote a short blurb on this here - https://www.pcblibraries.com/forum/ipc7093a-btc-qfn-solder-mask-defined-thermal-pad_topic2154.html This technology saves fabrication costs by not havi
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