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| Date: | Tue, 11 Oct 2011 10:39:18 -0400 |
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How does one do these calculations, what are the rules?
Is there a web site that can provide guidance? QFN's are difficult to
solder well
Karen Tellefsen - Electrical Testing
[log in to unmask]
908-791-3069
Re: [TN] [DC] QFN layout
Robert Kondner
to:
TechNet
10/11/2011 10:29 AM
Sent by:
TechNet <[log in to unmask]>
Please respond to rkondner
Pete,
I agree. Sometime it is less of an agenda and more of a case of never
having reflowed these parts.
My observation with QFNs has suggested having a good .5 to 1.0 mm of pad
outside the package. It acts like a solder reservoir area allowing solder
to flow out from under the leads as the component reflows and settles down.
So often I see suggest QFN footprint with no such area.
Just a non-qualified observation.
Bob K.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Pete
Sent: Tuesday, October 11, 2011 9:32 AM
To: [log in to unmask]
Subject: Re: [TN] [DC] QFN layout
I never trust the manufacturer's suggested footprint, always do my own
calculations. They have a different agenda than I need to have. Lately,
though, I'm finding their footprints much closer to mine.
Pete
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