I have been following this QFN discussion as about a year ago I worked a reliability problem for a QFN user.

One thing I noted is that the standoff is (of course) low. For anybody who is using QFNs: Have you done a Werner Engelmaier style mechanical reliability analysis on the parts?

Just asking. I saw them being used for avionics and was a little concerned about whether any planes I was to be flying on used QFNs. 

Greg Munie PhD
IPC Technical Conference Director
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-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Dave Schaefer
Sent: Saturday, February 23, 2013 11:33 AM
To: [log in to unmask]
Subject: Re: [TN] 48-pin QFN via-in-pad solder slug problem.

I am currently working on a design with 2 similar QFNs requiring via in slug for thermal and electrical reasons.
IPC-4761 gives a good summary of methods for handling these components; IPC-4761 Type VII (filled and conductively capped) appears to be the only sure bet solution.

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