Electronics Forum | Fri Jun 20 03:47:24 EDT 2008 | philip
Hi all, any good recommendation for PbF paste application to reduce voids underneath the QFN thermal pad (stencil thickenss? opening? via hole? reflow profile etc)? We have tried few stencil opening design but no significant improvement as seen. Ther
Electronics Forum | Fri Jun 20 18:32:55 EDT 2008 | hegemon
Back when I used to do a lot of these style devices we ran into the same problem you are describing. Use a pattern for the center pad area and keep the total coverage to about 68% of the pad area. Diagonal Stripes, tic tac toe, cloverleaf, dot array
Electronics Forum | Tue Jan 12 15:29:40 EST 2010 | davef
What is your concern regarding voiding in QFN solder connections?
Electronics Forum | Mon Sep 19 07:56:19 EDT 2005 | Pop
How we can improved the Solder voids on QFN Packaging. Actually we adjust the time for solking to long . But is not affected. Pls advise. ThANK YOU
Electronics Forum | Mon Jan 11 13:31:54 EST 2010 | cbart
I know IPC is working on a spec for voiding for QFN'S. However since its not released I'm curious what others have defined as the max allowable % voiding on the leads (not center ground).
Electronics Forum | Fri Jul 19 22:26:32 EDT 2019 | dhanish
Thanks Dave..What is the voids spec for QFN?This is another challenge with the QFN's
Electronics Forum | Sun Aug 10 21:57:25 EDT 2014 | cmchoue
Does IPC definition for "QFN Void Ration" ? Like IPC 7095 susgestion the BGA Void ratio.
Electronics Forum | Tue Mar 14 14:15:03 EDT 2017 | dontfeedphils
I've always been happy with ~25% or less combined voiding on QFN ground pads (depending on the pad dimensions).
Electronics Forum | Thu Jul 26 09:47:30 EDT 2018 | vchauhan
Rob, Thank you so much for your suggestions. Vinod.
Electronics Forum | Fri Jul 27 09:58:33 EDT 2018 | vchauhan
Dave & Rob, You guys are great. Appreciate your help.
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